CJ-4 oil for older flat tappet engines..

Posted by: Ponch

CJ-4 oil for older flat tappet engines.. - 01/04/14 11:03 PM

Hey all... I was wondering if today's CJ-4 HDEO lubes have enough anti-wear additives to protect older engines with flat tappet cams? I know that the CJ-4 HDEO's have reduced amounts of certain additives compared to older CI-4 version. I got asked this question today by a friend who has an older muscle car with a flat tappet motor. He was told that he should still run a ZDDP additive with a current CJ-4 lube if he chooses to run a diesel motor oil. Are CI-4 oils even available anymore besides from Amsoil?
Posted by: Chris142

Re: CJ-4 oil for older flat tappet engines.. - 01/04/14 11:08 PM

Should be penty unless it has super stiff valvesprings like a 375hp 396.regular pcmo is fine for a stock engine. Theres millions of engines...jeeps,chevys etc running around on sn oil and the owner does not know a thing about oils and they are not eating cams
Posted by: Ramblejam

Re: CJ-4 oil for older flat tappet engines.. - 01/04/14 11:09 PM

No additives are needed.

If you focus solely upon ZDDP, CJ-4 Mobil 1 Turbo Diesel Truck 5W-40 comes in at 1130ppm phosphorus, and 1250ppm zinc.

FYI, Mobil 1 15w-50 is specifically recommended for flat tappet applications -- 1200ppm phosphorus, and 1300ppm zinc.

Posted by: artificialist

Re: CJ-4 oil for older flat tappet engines.. - 01/04/14 11:09 PM

Lucas oil still makes a CI4+ oil. As for the ability of CJ-4 oil to protect flat lifter cams, it seems that if you have stock cams, or cams not built for performance, CJ-4 is more than strong enough to protect those cams.
Posted by: Ponch

Re: CJ-4 oil for older flat tappet engines.. - 01/04/14 11:28 PM

Thanks guys.. I believe it is a late 60's 396 motor with stiffer springs and bigger cam? He had mentioned to me also that he wasn't sure if a high viscosity oil such as 20w50 was needed or not? I did not know how to answer that..as I have no experience running older big block chevy's. I would think personally that any current 15w40 CJ-4 oil would do very well. Im not sure a HDEO 10w30 would suffice in this application? I know regarding older motors that bearing clearances and such are far larger/looser than today's engines.
Posted by: Chris142

Re: CJ-4 oil for older flat tappet engines.. - 01/04/14 11:42 PM

I dont know where the bearing clearance rumor started.The bearing clearances have not changed in 60+ yrs. Clearance depends on shaft diameter.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 12:00 AM

Originally Posted By: Ponch
Are CI-4 oils even available anymore besides from Amsoil?

I would think a CJ-4 would be adequate. Nonetheless, you should still be able to find some CI-4 and CI-4+ lubes out there. Up here, it's a little hard, and Imperial Oil yanked all the old stuff. The data sheets for them still exist at XOM in the U.S. though, for what it's worth.

As you're aware, there are other choices from Amsoil, along with RP XPS and Valvoline VR1 and Defy.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 06:06 AM

15W-40 CJ-4 is perfect, CJ-4 having typically 1000 ppm P (phosphorus of ZDDP), 1200 ppm P being the maximum limit. They also have other antiwear additives in the mix, such as moly, which greatly increase the potency of ZDDP.

The tests for CI-4 (or CI-4 Plus) are less stringent on wear than for CJ-4, despite CI-4 (Plus) having no ZDDP limit. So, you're better off with CJ-4 than CI-4 (Plus) if you're given the choice. ZDDP is not the entire story when it comes to wear. ZDDP is necessary for wear protection but it doesn't work well in protecting against wear while used alone and the other additives can make a big difference. So, it's more the balance of ZDDP and other additives.

I would recommend Mobil Delvac 1300 Super 15W-40. If cold starts are a problem in your area (temperatures below 10 F), use a 5W-40. (For 5W-40, Rotella and Delo are cheap and Mobil 1 Turbo-Diesel Truck is also a good option.) 5W-40 is thinner (HTHS viscosity ~ 3.7 cP vs ~ 4.3 cP for 15W-40) and will wear your flat tappets more than 15W-40 but it should still be acceptable. Don't use 10W-30 CJ-4 for your flat-tappet application if you're concerned about wear. Thicker oil is better for boundary lubrication (metal-to-metal contact), such as for the lubrication of flat tappets or other wear-prone valvetrain systems.
Posted by: widman

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 06:46 AM

If you want the answer in 30+ pages, I recommend this paper, where I went into detail about all the rumors and myths. It used to be in my signature, but I was told it doesn't meet the rules for signatures. http://www.widman.biz/Corvair/English/Links/Oil.html

The short answer in three parts is,

Yes, CI-4 or CJ-4 oils are fine. CJ-4 limits the ZDDP, and with some of the early versions, this might not have been great, but they have matured and are fine.

DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

Viscosity: Stay with the viscosity originally recommended by the manufacturer. IF it was 15W-40, I'd go to 5W-40 in most cases, especially if morning temperatures are below 50F. If you are going to race it high rpm's and high temp, you can go with a 5W-50. My Corvair originally called for 10W-30, which I was using, but I went to 5W-40 when I was planning on a long summer trip through an area here where normal ambient temperatures are over 120F, which will not do much to keep an air cooled engine in the 100 range.
Posted by: JHZR2

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 08:28 AM

If stiffer springs so it needs more zddp, just dope some in. You won't need a lot. Thing is, I'd do a voa before actually coming up with a treat rate to ensure that what you're doing is Ok. Don't want to dope anything too high.

Something like the redline assembly lube should do the trick. There are also zddp replacements...
Posted by: Flareside302

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 08:38 AM

if its a stock performance older engine.. any SN PCMO is fine after the cam has broken in. higher lift/duration cams go with a high zinc auto oil. Amsoil Zrod, Vr1.
Posted by: TiredTrucker

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 09:51 AM

My recent Schaeffer 15w40 syn blend CJ-4 had 1429 zinc, 1104 Phosphorus, 1161 Calcium, and 46 moly after 13733 miles on the oil. Haven't done a virgin analysis on it. I have been told by Schaeffer that their 5w40 full syn CJ-4 has the same add pack anti wear stuff as this one.
Posted by: A_Harman

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 02:43 PM

50/50 blend of Valvoline VR1 10w30 and 20w50.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 02:49 PM

Originally Posted By: widman
DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

I agree on this.

Flat tappets require extreme-pressure (= antiscore) additives such as moly more than ZDDP, which is not an antiscore but an antiwear additive. So, what you really need is an oil with a good balance of ZDDP and moly. I don't think too much moly makes too much of an harm other than more engine deposits but too much ZDDP will certainly result in less protection against wear after a certain optimum value of ZDDP. This could be as high as 2500 ppm P but don't take chances with aftermarket additives. There are also different types of ZDDP and the one used in your oil is optimized against other additives.

Once again, my recommendation for temperatures above 20 F is Mobil Delvac 1300 Super 15W-40, which has about 1000 ppm P and also has the extremely potent trinuclear moly. For lower cold-start temperatures, use Mobil 1 Turbo-Diesel Truck 5W-40 if you want premium protection. A cheaper alternative would be Rotella 5W-40, and an even cheaper alternative would be Delo 5W-40.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/05/14 05:28 PM

Originally Posted By: Gokhan
Originally Posted By: widman
DO not add ZDDP. You have no idea how badly you are screwing up particular formulations, upsetting their additive balance and adding deposits to the engine. And if you go too high, you will have cam galling and other problems.

I agree on this.

Flat tappets require extreme-pressure (= antiscore) additives such as moly more than ZDDP, which is not an antiscore but an antiwear additive. So, what you really need is an oil with a good balance of ZDDP and moly. I don't think too much moly makes too much of an harm other than more engine deposits but too much ZDDP will certainly result in less protection against wear after a certain optimum value of ZDDP. This could be as high as 2500 ppm P but don't take chances with aftermarket additives. There are also different types of ZDDP and the one used in your oil is optimized against other additives.

Once again, my recommendation for temperatures above 20 F is Mobil Delvac 1300 Super 15W-40, which has about 1000 ppm P and also has the extremely potent trinuclear moly. For lower cold-start temperatures, use Mobil 1 Turbo-Diesel Truck 5W-40 if you want premium protection. A cheaper alternative would be Rotella 5W-40, and an even cheaper alternative would be Delo 5W-40.

Also note that Non-ILSAC (non-GF-5) SN oils are exempt from the 800 ppm P ZDDP maximum limit. This means xW-40 and xW-50 SN oils have no ZDDP maximum limit. Also, high-mileage SN oils of any viscosity have no ZDDP maximum limit, as they are not GF-5. ZDDP maximum limit is imposed by the "Resource Conserving" (of the GF-5) designation, not the SN designation by itself.

This said, Mobil 1 0W-40 SN is a great alternative for flat-tappet engines. It has about 1000 ppm P (of ZDDP), which is similar to CJ-4 oils, and (probably) has trinuclear moly, the most potent kind of moly. It also has another advantage against CJ-4 oils: It's tailored more toward gasoline engines. This is unlike CJ-4 oils, which are tailored more toward diesel engines.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 01:04 AM

Originally Posted By: Gokhan
Also note that Non-ILSAC (non-GF-5) SN oils are exempt from the 800 ppm P ZDDP maximum limit. This means xW-40 and xW-50 SN oils have no ZDDP maximum limit. Also, high-mileage SN oils of any viscosity have no ZDDP maximum limit, as they are not GF-5. ZDDP maximum limit is imposed by the "Resource Conserving" (of the GF-5) designation, not the SN designation by itself.

The problem is, though, that just because certain viscosity or certification examples have no limitation doesn't mean they pour the stuff in. Plenty of non-ILSAC rated oils, HM examples, or pre-limitation examples had rather low zinc and phosphorous concentrations, lower, in fact, than some modern ILSAC formulations.

That's why I do like things such as most HDEOs or VR1 for such applications. At least we have confirmed, elevated additive levels.

Did I ever mention that a local WM here sells VR1 cheaper than normal PCMO? wink
Posted by: Jim Allen

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 07:03 AM

Most of the current crop of HDEOs have MORE ZDDP than the PCMO oils from back in the day. If you go to Blackstone Lab's website and find the newsletters from 2012, you will see a batch of vintage oil VOAs. They tested unused oils as old as the 1930s and 1940s. If you look at the more recent oils from the '60s and '70s, you will find some with very little ZDDP and some with very moderate amounts under 1000 ppm. A few showed on 100-300 ppm. A few are as high as 1200 ppm. I have posted some VOAs from the late '80s and they were around 1000 ppm. In many cases even the current PCMO has enough zinc for low performance flat-tappet applications that aren't breaking in a new cam. I think one is prudent to want a bit more ZDDP than 800 ppm and HDEOs are but one alternative. You might look at the QS Defy line as well. The HDEOs are a good choice but the viscosity choices are more limited.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 12:06 PM

I would go with Mobil 1 0W-40 SN -- 1000 ppm P. Get a 5 qt jug from Walmart.

Here is the table of Mobil 1 oils (PDF file), showing their ZDDP levels. Some go up to 1750 ppm P, well above the CJ-4 maximum limit. GF-5 minimum and maximum limits are 600 - 800 ppm P. CJ-4 minimum and maximum limits are 0 - 1200 ppm P (no minimum limit). Also note that the type of ZDDP used in diesel-engine oil is more an antioxidant than an antiwear additive. This is in contrast to gasoline-engine oils, where the type of ZDDP used is more an antiwear than an antioxidant additive.

Here is the Q&A from the Mobil 1 Web site:

Question:
Mixing Motor Oil to Reach the Right ZDDP Level for Classic Cars
For an older, flat tappet, performance motor with inherent cam wear issues is there any benefit to mixing high ZDDP Mobil 1 Racing 4T 10W-40 to Mobil 1 High Mileage 0W-30 oil? The 15W-50 creates TOO MUCH oil pressure. It would be nice if you had a product for 'Classic' cars, high ZDDP, 0W-30 and 0W-40. I have used nothing but Mobil 1 for 15+ years.
-- Bill McCauley, Tallmadge, OH

Answer:
Mobil 1 0W-40 already contains a higher level of ZDDP (1000 ppm) that could benefit your flat tappet engine. We also have a Mobil 1 High Mileage 10W-40 (1000 ppm); see our table listing the phosphorous levels for all Mobil 1 synthetic motor oils.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 12:22 PM

Originally Posted By: Gokhan
Also note that the type of ZDDP used in diesel-engine oil is more an antioxidant than an antiwear additive. This is in contrast to gasoline-engine oils, where the type of ZDDP used is more an antiwear than an antioxidant additive.

The following is a good read on why you shouldn't use diesel-engine oils in flat-tappet gasoline engines:

Why NOT diesel or racing oil? (link from Cam-Shield oil treatment)

Contrary to the current internet buzz that diesel oil is the oil to use in a gasoline flat tappet cam engine, the correct oil to use on a continuous basis in your classic car's flat tappet cam engine is an oil designed for gasoline engines that contains the correct level of ZDDP anti-wear protection. Similarly, a race oil is not recommended for continued use in a street driven gasoline engine.

If you look on the back of a bottle of oil you will see the API performance classification for the oil. Diesel oils with API credentials of CI-4, CI-4 Plus, CJ-4 will typically have Zinc levels around 1100 parts per million (ppm). For a flat tappet cam gasoline engine with moderate valve spring pressures (such as a flat head engine) the generally accepted minimum level of protection is 1200 to 1300 ppm of Zinc. For muscle cars and hot rods with higher valve spring pressures, 1600 ppm will give uncompromised protection. Race cars generally need around 2000 ppm. Break-in of a new cam is generally best protected with around 2500 ppm (in addition to the molybdenum cam lobe lube). Current API SM/ILSAC GF-4 gasoline engine oils have incredible performance capabilities and will have approximately 850 ppm of Zinc, but will need to be supplemented with ZDDP to make them suitable for use in flat tappet cam engines in classic cars, hot rods and race cars. It is extremely important to add a highly concentrated ZDDP product so as not to dilute the oil and thus impact the performance integrity of the engine oil.

Here are the differences between diesel engine oil and gasoline engine oil. In a modern diesel engine there is substantial exhaust soot contamination that the engine oil must contend with. Diesel oil is designed with much higher levels of detergency and dispersency to fight the soot contamination. Like ZDDP anti-wear chemistry, detergents are a surface active chemistry and compete directly for space on metal surfaces, such as the cam lobe and lifter face. So, in practice, the effective level of Zinc anti-wear is a bit lower than what we expect it to be based solely on chemical analysis. Additionally, the ZDDP that is generally used in diesel formulas is primary ZDDP (which activates at higher engine temperatures) since a diesel engine runs predominantly at operating temperature. In a gasoline engine, we must have both primary and secondary ZDDP (which activates at lower temperatures) since the engine will experience a significant number of cold starts. Also, the viscosity modifier polymers that are used in multi-viscosity engine oil to prevent viscosity loss at operating temperature (to protect the bearings) are different for diesel oil and gasoline oil. Diesels operate at essentially the same rpm all day long and need polymers that are shear stable to protect the bearings. Gasoline engines experience many large ranges of rpm during operation and require polymers that have both shear stability and thickening efficiency capability to protect the bearings.

Race oil formulas are typically designed with reduced levels of detergency and dispersency to improve performance of the anti-wear and friction modifier chemistries. Race oil is typically changed very frequently and race engines are typically re-built frequently. For a street driven gasoline engine, the correct levels of detergency and dispersency are required to prevent deposit formation (particularly at the piston rings), and sludge formation, from contaminants. This becomes more important to classic car owners who may only drive the vehicle occasionally and who change the oil once or twice a year.
Posted by: Jim Allen

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 01:31 PM

Originally Posted By: Gokhan
For a flat tappet cam gasoline engine with moderate valve spring pressures (such as a flat head engine) the generally accepted minimum level of protection is 1200 to 1300 ppm of Zinc.


Generally accepted by whom? The companies that make specialty oils for "classic" cars and want to steer you away from other, less expensive oils? Or is it from companies that sell ZDDP additives that want to scare us into more ZDDP? Actually, I see you clipped the sales pitch from the Cam-Shield website in your post, in addition to linking to it, and that is not your own writing. I would hardly regard that as an objective source of information.

The less complex truth is the API has backrated many SM and SN oils for flat tappet engines. That may or may not be the whole story, but testing was done to qualify the ratings based on the 800 ppm levels of ZDDP. And remember that their are other additives that do the same thing. I personally think nearer 1000 should be a minimum, no other additives in the picture.

One good clarification point: A purely "diesel rated" oil, e.g. API CI only, is not suitable for any gas engine. That has less to do with ZDDP than other things, however. But when we talk about HDEOs, we are talking about dual rated oils that may be CJ-4/SM or CI-4/SM. They are dual rated for gas or diesel and contain enough for diesels and way more than a low-po flat tappet engine requires unless breaking in a new cam.

FInally, if 1300 is the minimum amount required, how do you account for the fact that many older oils, period to the era of the flat tappet, had nowhere near that much?
Posted by: Jim Allen

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 01:50 PM

I forgot to mention that while the high detergency and dispersency additives in a diesel rated oil can reduce the effectiveness of a ZDDP package vs the package in a gas engine, but it is related to the activation temps of the product. The diesel rated oil reputedly requires a higher activation temp. By how much, I do not know. Is this an issue? I doubt it. Do diesel have substantially higher oil temps than a gasser? Not really. It's more an operational cycle issue, whereby diesels most often are run hard, long and hot versus a higher percentage of gasser are short hopped and seldom reach full oil temp. In theory, a modern, short hopped light truck diesel could run into the same issues... if that's an truly an issue. So while the differences in ZDDP chemistry between a gas and dual rated diesel oil may exist, it seems doubtful it's a significant issue. I see the lack of optimal viscosity choices as more an issue, but it you are willing to get intothe more expensive dual-rate oils, that may not be much of an issue. Especially if you consider that many "classic" or late generation flat tappet engines were spec'ed of 10W30 or 10W40 oils that are esily matched in the HDEO realm.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 03:18 PM

Originally Posted By: Jim Allen
Originally Posted By: Gokhan
For a flat tappet cam gasoline engine with moderate valve spring pressures (such as a flat head engine) the generally accepted minimum level of protection is 1200 to 1300 ppm of Zinc.

Generally accepted by whom? The companies that make specialty oils for "classic" cars and want to steer you away from other, less expensive oils? Or is it from companies that sell ZDDP additives that want to scare us into more ZDDP? Actually, I see you clipped the sales pitch from the Cam-Shield website in your post, in addition to linking to it, and that is not your own writing. I would hardly regard that as an objective source of information.

The less complex truth is the API has backrated many SM and SN oils for flat tappet engines. That may or may not be the whole story, but testing was done to qualify the ratings based on the 800 ppm levels of ZDDP. And remember that their are other additives that do the same thing. I personally think nearer 1000 should be a minimum, no other additives in the picture.

One good clarification point: A purely "diesel rated" oil, e.g. API CI only, is not suitable for any gas engine. That has less to do with ZDDP than other things, however. But when we talk about HDEOs, we are talking about dual rated oils that may be CJ-4/SM or CI-4/SM. They are dual rated for gas or diesel and contain enough for diesels and way more than a low-po flat tappet engine requires unless breaking in a new cam.

FInally, if 1300 is the minimum amount required, how do you account for the fact that many older oils, period to the era of the flat tappet, had nowhere near that much?

I didn't post their article for their claims on ZDDP levels. Sure, they sell ZDDP treatment and they will claim you need more ZDDP.

It's of course true that it's very important to have a good balance between different additives in the oil. Even the article states that. For this reason, when people blend their own oils (mixing different brands or viscosities), I have concerns that the resulting mix may actually be worse than the constituents. I also have concerns against using any kind of aftermarket oil additive.

However, the reason I posted the article is that they make a very good point about diesel-engine oils and racing oils not being the optimum oils for gasoline engines. Their point about detergent levels being too high in diesel-engine oils and too low in racing oils is valid. Their point about diesel engines using different ratios of primary to secondary ZDDP, optimized for diesel engines, is also valid. They also make a good point about different types of viscosity-index improvers used. This is all very useful and true information.

Your point about the CJ-4/SM dual certification misses the mark. While it's true that virtually any CJ-4 oil is dual-certified for SM use, what your point is missing is that CJ-4/SM oils are exempt from some tests and specs of SM. They only meet some of the specs and tests of SM. Quoting from API:

"If API CI-4 and/or CJ-4 categories precede the S
category and there is no API Certifi cation Mark, the
Sequence VG (ASTM D6593), Ball Rust (ASTM D6557),
and Gelation Index (ASTM D5133) tests are not required."


"For all viscosity grades: If API CH-4, CI-4 and/or
CJ-4 categories precede the S category and there
is no API Certifi cation Mark, the S category limits for
phosphorus, sulfur, and the TEOST MHT do not apply.
However, the CJ-4 limits for phosphorus and sulfur do
apply for CJ-4 oils."


The bottom line is that the dual-certified CJ-4/SM oils are not intended for mainstream gasoline-engine use. They are intended for some fleet use, where the fleet operators may find it more convenient to use a single type of oil.

CJ-4/SM oils are not optimized for gasoline engines, and the article helps explain it why, and the API reference I quoted officially tells you that they are not optimized for gasoline engines.

My recommendation once again is Mobil 1 0W-40 SN without any aftermarket additives. Any other high-quality xW-40 SN or xW-50 SN oil with good ZDDP and moly levels intended primarily for gasoline engines will also work well. Do not use xW-30 or thinner, as they don't provide as good boundary lubrication because of thinner oil film. Also, remember that only the "Resource Conserving" SN oils have a maximum limit on ZDDP but all CJ-4 oils have a maximum limit of 1200 ppm P on ZDDP. In addition, the type of ZDDP used in SN-only (gasoline-engine) oils is a more potent antiwear additive in gasoline engines than the type of ZDDP used in CJ-4 (heavy-duty-diesel-engine) oils.
Posted by: Doug Hillary

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 03:56 PM

Hi,
Gokhan - Sorry to intrude again but many iterations from you in this Thread (and some others) fly in the face of reality!

For various reasons I have used HDEOs in petrol engines since the late 1950s - I may say and ALL with excellent end results. So have many Fleet Owners with millions of $ tied up in assets - they typically have great results too

Ensuring that the correct API/ACEA/Manufacturer requirements are met is always paramount to long life and durability on the way

Of course like any other contributor your input is welcome no doubt, but re-reading some of your own rhetoric may assist your understanding of the subject.

Experience plays a great part when making statements here on BITOG - at least!
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 04:45 PM

Originally Posted By: Doug Hillary
Hi,
Gokhan - Sorry to intrude again but many iterations from you in this Thread (and some others) fly in the face of reality!

For various reasons I have used HDEOs in petrol engines since the late 1950s - I may say and ALL with excellent end results. So have many Fleet Owners with millions of $ tied up in assets - they typically have great results too

Ensuring that the correct API/ACEA/Manufacturer requirements are met is always paramount to long life and durability on the way

Of course like any other contributor your input is welcome no doubt, but re-reading some of your own rhetoric may assist your understanding of the subject.

Experience plays a great part when making statements here on BITOG - at least!

Doug, we're not saying here that a CJ-4/SM oil wouldn't work in a gasoline engine. That would be ridiculous. If that's how you read my posts, you're mistaken. I myself used CJ-4 15W-40 in my car for many years with very good results.

Regarding the "certification" of dual-certified (CJ-4/SM) oils, even API states that these oils may not be optimal for gasoline engines, as they don't meet every requirement of an SM-only or SN-only oil.

The point is that an SN-only oil is better optimized for a gasoline engine and there is really no benefit of using a CJ-4 oil in a gasoline engine. You don't need the high concentration of soot dispersants of a CJ-4 oil in a gasoline engine. Too much dispersants strip the antiwear additives away, which is not good for this user's flat-tappet application. I suggested Mobil 1 0W-40 SN with 1000 ppm P, which is the same as the typical ZDDP concentration in a CJ-4 oil. He can also use something like a Pennzoil Yellow Bottle 10W-40 SN, which has about 850 ppm P, and save a lot of money, given the chances that his engine uses a lot of oil.
Posted by: Jim Allen

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 05:16 PM


I agree that dual rated HDEOs may not be optimal for all engines but I submit they can be optimal or nearly so for older flat tappet engines when measured against the older specifications they were originally certified under. Flat tappet engines were largely gone by the mid 1990s, so they would have operated under a lower oil spec than today's oils can offer. It doesn't take much to beat those old oils with the array of lubricant available today, up to and including HDEOs.

The fact that HDEOs are exempt from certain API gas oil tests (likely because there is a higher or different standard for a similar test in the CJ certification) is no condemnation in and of itself.

As to the diesel primary vs secondary ZDDP ratios being different than a gas formulation, it's a point but I'm not convinced it's particularly noteworthy one in the grand scheme of things. If you are only talking about "perfect world" stuff, I'll concede the point. If we are talking about general viability of HDEOs within the context of an ordinary engine, nothing I have seen would indicate a measureable difference on any level you'd care to mention, even a long ways down the road. As Doug mentioned, there has been a whole lot of practical evidence aquared that HDEOs work fine in gas engines. There are many fleets that have used HDEOs for millions of miles in their gas fleets that delivered perfectly acceptable performance.

I don't disagree that the oils you recommended are fine oils and suitable for the purpose (we could argue about your viscosity recommendations... ( : < ), I think that HDEOs are more a viable alternative than you seem to want to admit.

Also, you never commented on the old oil VOAs and the apparent low levels of ZDDP.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/06/14 05:32 PM

Originally Posted By: Jim Allen
I forgot to mention that while the high detergency and dispersency additives in a diesel rated oil can reduce the effectiveness of a ZDDP package vs the package in a gas engine, but it is related to the activation temps of the product. The diesel rated oil reputedly requires a higher activation temp. By how much, I do not know. Is this an issue? I doubt it. Do diesel have substantially higher oil temps than a gasser? Not really. It's more an operational cycle issue, whereby diesels most often are run hard, long and hot versus a higher percentage of gasser are short hopped and seldom reach full oil temp. In theory, a modern, short hopped light truck diesel could run into the same issues... if that's an truly an issue. So while the differences in ZDDP chemistry between a gas and dual rated diesel oil may exist, it seems doubtful it's a significant issue. I see the lack of optimal viscosity choices as more an issue, but it you are willing to get intothe more expensive dual-rate oils, that may not be much of an issue. Especially if you consider that many "classic" or late generation flat tappet engines were spec'ed of 10W30 or 10W40 oils that are esily matched in the HDEO realm.

See this reference from Automotive Lubricants Reference Book. High detergency is always bad for wear protection, as it also strips away the antiwear, extreme-pressure, and friction-modifier, and oil films from metal parts while it cleans them. Regarding primary and secondary ZDDP, it has to do more with the combustion temperature, which is greatly higher in diesel engines, than the oil temperature. Secondary ZDDP is more potent than primary ZDDP as an antiwear additive. Gasoline-engine oils have more secondary ZDDP as wear is a bigger concern in gasoline engines and there is less concern of ZDDP decomposition.

However, when attempts were made to introduce detergent additives into gasoline
engines, or to use diesel lubricants containing detergents in gasoline engines, there
were many failures with heavy wear resulting particularly in the cam and tappets.
The initial reactions were that these detergents were either chemically attacking the
metal or that their apparently colloidal metal compounds were actually abrading the
surfaces. This is now known not to be the case, and the effect is due to the highly
surface active nature of the detergents. which causes them to compete strongly for
possession of the metal surfaces with boundary layer and antiwear additives or
natural lubricity compounds in the oil. Because most detergents do not have
significant antiwear capability, the surfaces become relatively unprotected, and wear
takes place where loadings are heavy. To overcome this, the concentration of ZDDP,
or other antiwear additives, must be increased substantially for it to compete successfully
with the detergent and obtain some measure of occupation of the metal surfaces.

Today, ZDDP is the predominant antiwear additive used in crankcase oils, although
it is a class of additive rather than one particular chemical. The solubilizing groups
that enable the metal dithiophosphate to be soluble in oil can either be alkyl (straight
or branched chains) or aryl (aromatic rings). The antiwear activity (or rather the
sensitivity of the additive to commence giving antiwear protection) varies inversely
with the thermal stability of the particular structure. This increases with carbon number
and in the order secondary alkyl (the least stable and the most potent), through
primary alkyl to aryl types (the most stable but least potent). Diesel engines run
considerably hotter in the ring zone than gasoline engines, and ZDDP decomposition
tends to produce lacquer in this area. On the other hand, diesel engines, because of
their design and metallurgy, tend to have fewer wear problems than gasoline engines.
Thus, for a simple diesel oil, a more stable but less potent type of ZDDP can be
tolerated. However, when formulating multipurpose oils for use in gasoline engines,
high-speed passenger-car diesel engines, and larger diesel engines, it is necessary
to select carefully between the possible ZDDP types available and sometimes to
use balanced mixtures of two or more types. In some countries, restrictions on
lubricant phosphorus content, caused by concern for exhaust catalyst poisoning,
can limit the level of ZDDP that can be used. A phosphorus limit of 0.05% maximum
has been common for many years in Japan, and a limit of 0.1% maximum is
common elsewhere.


What this reference book is saying is really interesting:

The reason why diesel-engine oils have more ZDDP is not because they are meant to provide more protection against wear. On the contrary, it's only to make up for higher concentrations of detergents and dispersants in diesel-engine oils, which increase wear!

The long story short, you don't get more wear protection for your flat tappets with 1200 ppm of ZDDP in a diesel-engine oil than you get with 800 ppm ZDDP in a gasoline-engine oil, as the higher concentration in a diesel-engine oil is only to make up for wear-inducing detergents and dispersants. In addition, there are other things in a diesel-engine oil additive package that are not optimized for gasoline engines, including the type of ZDDP, amount of friction modifiers, type of viscosity-index improvers, etc. There is a reason why the additive companies make separate additive packages for CJ-4 and SN/GF-5 oils.
Posted by: Jim Allen

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 05:36 AM

I've read that book too. I'll quote back part of your quote:

"However, when formulating multipurpose oils for use in gasoline engines,
high-speed passenger-car diesel engines, and larger diesel engines, it is necessary
to select carefully between the possible ZDDP types available and sometimes to
use balanced mixtures of two or more types."

I think that describes a modern HDEO, a balanced product.

You have still not commented on vintage oil ZDDP levels.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 10:24 AM

Originally Posted By: Jim Allen
I've read that book too. I'll quote back part of your quote:

"However, when formulating multipurpose oils for use in gasoline engines,
high-speed passenger-car diesel engines, and larger diesel engines, it is necessary
to select carefully between the possible ZDDP types available and sometimes to
use balanced mixtures of two or more types."

I think that describes a modern HDEO, a balanced product.

You have still not commented on vintage oil ZDDP levels.

Jim, Automotive Lubricants Reference Book was written by SAE, and I couldn't imagine any other explanation that would illuminate better on this subject than the excerpt from the book I posted above. It put the final period on this matter and everything is crystal-clear now.

Yes, they of course use a mix of primary and secondary ZDDP, and we knew that already. However, there is a good possibility that a diesel oil has more primary ZDDP than a gasoline oil, which has more secondary ZDDP. I won't reexplain the difference between the two and why diesel and gasoline oils tend to use different ratios of primary to secondary, as it's explained in the excerpt from the book I posted above.

The answer to your quiestion about vintage oil is explained in glory detail in the first paragraph in the excerpt. That's why I didn't reexplain it. But let me say it briefly -- if you don't have detergents, you need much smaller amounts of ZDDP.

So, why I have to keep reexplaining this -- I don't know -- as the excerpt clearly explained it and put the final word on it. But I will state the conclusion from the excerpt one more time, which is crucial: It's a big fad/myth/misconception that diesel oils (HDEOs) offer better wear protection, such as for flat-tappet engines, because they have more ZDDP (0 - 1200 ppm P) than gasoline-engine oils (600 - 800 ppm P). The only reason why HDEOs have more ZDDP is to make up for the high level of detergents, which increase wear. You will get no increased wear in a flat-tappet or other engine with an SN/GF-5-only gasoline-engine oil (PCMO) than you will with an HDEO. In fact, chances are that, in a gasoline engine, with an SN/GF-5-only PCMO, you will get less wear than with an HDEO, as the type of ZDDP used is more potent as an antiwear additive (as gasoline engines are more prone to wear than diesel engines) and the detergent levels are smaller, along with many other optimizations of additives for gasoline-engine use. Once again, this is clearly explained in the excerpt from the SAE book above and I will not explain it one more time.

That excerpt from the SAE book should be made a sticky thread in the HDEO section for those who are sucked into using HDEOs because they rather mistakenly assume the higher level of ZDDP will help them decrease wear in their gasoline-engine application, while they don't realize that HDEOs are more likely to cause increased wear in gasoline engines due to their high detergent levels and other reasons (less secondary ZDDP, additives not optimized for gasoline-engine use, etc.) explained above.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 11:09 AM

Originally Posted By: Gokhan
Regarding the "certification" of dual-certified (CJ-4/SM) oils, even API states that these oils may not be optimal for gasoline engines, as they don't meet every requirement of an SM-only or SN-only oil.

First off, unfortunately, the quotes you posted from the Cam-Shield people are filled with tripe. Their survival depends on us buying into the idea that there was much more ZDDP in oils of yesteryear and that an additive is the solution. Neither holds a lot of water.

Additionally, back in the day, just about every engine oil out there was dual rated. Was that a problem? Also, many of these older, high performance applications really don't have a need for the finest, most carefully tuned lubes available today. Modern engines aren't that sensitive. Older ones are even less so.

We're also exaggerating the detergency of HDEOs. Too many of these references are dated; Richard indicated how things have changed even within the lifespan of CJ-4. ULSD is the norm. TBN in HDEOs is lower than it used to be. We also shouldn't ignore cost. Some of us get HDEOs, even synthetic ones, at a significant discount. My price on Delvac 1 rivals that of conventional. That makes it a pretty easy choice.

Also, with reference to some of the ultra-low phosphorous HDEOs - those are usually easy to spot. Delvac 1 LE 5w-30 is advertised as such, yet is still dual rated; I'd probably run it without concern, either. Others with low/no ZDDP lack the gasoline rating altogether; those I'd avoid considering their not suitable for gasoline engines.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 11:32 AM

Originally Posted By: Garak
Originally Posted By: Gokhan
Regarding the "certification" of dual-certified (CJ-4/SM) oils, even API states that these oils may not be optimal for gasoline engines, as they don't meet every requirement of an SM-only or SN-only oil.

First off, unfortunately, the quotes you posted from the Cam-Shield people are filled with tripe. Their survival depends on us buying into the idea that there was much more ZDDP in oils of yesteryear and that an additive is the solution. Neither holds a lot of water.

Additionally, back in the day, just about every engine oil out there was dual rated. Was that a problem? Also, many of these older, high performance applications really don't have a need for the finest, most carefully tuned lubes available today. Modern engines aren't that sensitive. Older ones are even less so.

We're also exaggerating the detergency of HDEOs. Too many of these references are dated; Richard indicated how things have changed even within the lifespan of CJ-4. ULSD is the norm. TBN in HDEOs is lower than it used to be. We also shouldn't ignore cost. Some of us get HDEOs, even synthetic ones, at a significant discount. My price on Delvac 1 rivals that of conventional. That makes it a pretty easy choice.

Also, with reference to some of the ultra-low phosphorous HDEOs - those are usually easy to spot. Delvac 1 LE 5w-30 is advertised as such, yet is still dual rated; I'd probably run it without concern, either. Others with low/no ZDDP lack the gasoline rating altogether; those I'd avoid considering their not suitable for gasoline engines.

Perhaps you can shrug off the Cam-Shield reference but the SAE reference is quite clear and authoritative. You should read the SAE reference above carefully.

CJ-4 oils still have more dispersants than any other diesel oil of the past (CI-4 etc.), as they have excellent, never-before-seen soot control (which you don't need for your gasoline application). Dispersants also reduce the effectiveness of ZDDP as do detergents (see this reference).

If you think you need an xW-40 oil and you live in Canada, Mobil 1 0W-40 or similar, not Mobil Delvac HDEO, is the right oil for you. If you're OK with xW-30 viscosity, pick up any synthetic 0W-30 or synthetic 5W-30. I can't believe you would be picky on the price of the oil because you have a newer-model luxury car.
Posted by: Jim Allen

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 12:00 PM

Originally Posted By: Gokhan

Perhaps you can shrug off the Cam-Shield reference but the SAE reference is quite clear and authoritative. You should read the SAE reference above carefully.



It is authoritative in defining general concepts but does it address this issue directly? I.e. what is the equivalency? Does 1200 PPM net ZDDP (primary and secondary) content in a dual rated HDEO, with all its extra dispersency and detergency additives, still exceed the level of anti-wear protection found in current SN levels? Or not? Can you answer that?

BTW, neither SN or CJ-4 existed when the book was written. And it does not appear to be an SAE book either. It was published in 2003 and given the timeframe of getting a manuscript from author to print, he was probably reflecting 2001 or 2002 technology. It's 2014 now and there have been many advances since, both in PCMO and HDEO.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 12:07 PM

I read what I could, since the link won't show me much beyond the cover. Nonetheless, from the quote you provided, nothing I read worries me in the least. Of course detergents and dispersants compete with AW compounds. That's nothing new or surprising, and has been observed in gasoline engine oils, too.

I certainly don't need a synthetic. Most of the time I have had the G, it's been on a steady diet of PYB 5w-30. But, I had some Delvac 1 ESP 5w-40 in stock and decided to use it up. Given the price and the much easier shopping experience, I'm considering sticking with it for the long run. Note that XOM specifically endorses it for high performance applications.

Do note something about M1 0w-40. If Delvac 1 ESP 5w-40 is inappropriate because it's dual rated, what makes M1 0w-40 appropriate? After all, it is an A3/B4 rated oil. A3 is for gas, B4 is for diesel. Hence, it's also a dual rated oil.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 12:26 PM

Originally Posted By: Jim Allen
Originally Posted By: Gokhan

Perhaps you can shrug off the Cam-Shield reference but the SAE reference is quite clear and authoritative. You should read the SAE reference above carefully.

It is authoritative in defining general concepts but does it address this issue directly? I.e. what is the equivalency? Does 1200 PPM net ZDDP (primary and secondary) content in a dual rated HDEO, with all its extra dispersency and detergency additives, still exceed the level of anti-wear protection found in current SN levels? Or not? Can you answer that?

BTW, neither SN or CJ-4 existed when the book was written. And it does not appear to be an SAE book either. It was published in 2003 and given the timeframe of getting a manuscript from author to print, he was probably reflecting 2001 or 2002 technology. It's 2014 now and there have been many advances since, both in PCMO and HDEO.

You're now being nothing but argumentative.

It's a SAE publication -- see the second page.

The knowledge ten years ago (when this book was published) applies more than well enough to the present day. On top of that, the book explained the history of ZDDP use in oil and answered your question regarding vintage oil -- yet, you're still being childishly argumentative. You simply don't understand how science works. You must think scientific publications are like iPhones that need to be updated every year. We are not discussing the itty-bitty difference in CJ-4 & CI-4 or SN and SM here. The general ideas in the book apply extremely well to this very particular subject of this thread.

The questions you're asking now are becoming argumentative and ridiculous. No one can answer exactly how much wear protection a particular oil or a given amount of ZDDP offers and we are not here to discuss that. We have been just discussing whether an HDEO or PCMO is generally more suitable for gasoline-engine use, especially one with flat tappets, and that has now been well-answered.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 12:36 PM

Originally Posted By: Garak
Do note something about M1 0w-40. If Delvac 1 ESP 5w-40 is inappropriate because it's dual rated, what makes M1 0w-40 appropriate? After all, it is an A3/B4 rated oil. A3 is for gas, B4 is for diesel. Hence, it's also a dual rated oil.

Hi Garak,

No, I wouldn't consider A3/B4 dual-rated, as all oils fit in one of the ACEA A/B categories. B categories can hardly be considered true diesel categories, as there is virtually no oil sold that doesn't fall into an "A/B" category. In other words, for example, any Pennzoil yellow bottle is a dual-rated oil in that sense. The categories in ACEA corresponding to the API CJ-4 etc. categories are ACEA E9 etc. -- the true heavy-duty-engine-oil categories.

See this reference for the understanding of the ACEA categories.
Posted by: Jim Allen

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 07:30 PM

Originally Posted By: Gokhan

You're now being nothing but argumentative.


Since you want to get personal, I merely am mirroring your snotty, condescending, holier-than-thou style. You've read a book and now you're an instant expert claiming to understand it all and anyone who doesn't bow and scrape doesn't know squat. That's quite your style..

Originally Posted By: Gokhan

It's a SAE publication -- see the second page.


Ain't seeing it. Says it's a 2003 pub from Elsevier B.V. in the Netherlands. No SAE info. If it matters.

Originally Posted By: Gokhan


The knowledge ten years ago (when this book was published) applies more than well enough to the present day. On top of that, the book explained the history of ZDDP use in oil and answered your question regarding vintage oil -- yet, you're still being childishly argumentative. You simply don't understand how science works. You must think scientific publications are like iPhones that need to be updated every year. We are not discussing the itty-bitty difference in CJ-4 & CI-4 or SN and SM here. The general ideas in the book apply extremely well to this very particular subject of this thread.

No one can answer exactly how much wear protection a particular oil or a given amount of ZDDP offers and we are not here to discuss that. We have been just discussing whether an HDEO or PCMO is generally more suitable for gasoline-engine use, especially one with flat tappets, and that has now been well-answered.


Again the personal insults. Basically I agree that the concepts don't change too much but I disagree that the wear protection can't be measured. It can. Whether it has or not in the context of this discussion, we do not know. The practical answer to the question is that an HDEO is probably more than adequate for a flat tappet engine. Is it optimal? I never said that it was, just that it's a viable low cost, easy access option, a generally suitable option, with few downsides for the average joe.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/07/14 08:17 PM

How is it personal insults when I'm pointing out that you're being argumentative, especially when you're being so? How many references have you posted so far to counter my claims? I've answered many of your questions and your response every time has been to come up with a new question.

I told you to look at the second page (copyright page) of the book but you didn't. It was published by SAE in September 2004, 9 years 4 months ago. It's the second edition:





You dismissed a nine-year-old authoritative SAE book on engine oil saying that it was outdated.

Sure, the wear can be measured. It's measured by the Sequence IVA (ASTM D6891) test. However, good luck finding any results of the test disclosed. The only results disclosed I am aware of were during the Mobil 1 - Valvoline SynPower - Castrol Edge war. The maximum acceptable wear limit is 90 microns and the SM version of Mobil 1 had showed 180 microns of wear, according to private tests:



How is HDEO more affordable than PCMO? The original question in this thread was whether a flat-tappet engine could benefit from higher levels of ZDDP in CJ-4 oils. The answer, according to the references I posted, one of them being authoritative, is probably not, the reason having got to do the with type of ZDDP (primary vs. secondary), amount of dispersants and detergents, and optimization of the additive packages for gasoline or diesel applications. Would a CJ-4 be adequate for flat tappets? Probably, yes, and I've never said no. However, being adequate wasn't the original question. The original question asked whether a CJ-4 oil was a better choice than an SN/GF-5 oil. The answer, according to this reference, is no, and everything it says makes perfect sense. In fact, chances are that an SN/GF-5 oil provides better wear protection for flat tappets than a CJ-4 oil. Extra ZDDP in CJ-4 oils is to make up for wear induced by extra dispersants and detergents in CJ-4 oils, not to provide additional wear protection surpassing wear protection in gasoline engines. In fact, gasoline engines are more wear-prone and they demand more wear protection than diesel engines.

You can keep being argumentative and claim that we still don't know for sure because we have never seen the Sequence IVA results. Yes, you can never be sure which oil provides less wear in Sequence IVA or in real-life driving. However, we can still give a general answer to the question asked here originally.

After being told about the different types of ZDDP (primary, secondary, or a certain mix of a certain ratio of the two) used in diesel vs. gasoline oil and wear-inducing dispersants and detergents in diesel oil, if someone still thinks that 1000 ppm P of ZDDP in a CJ-4 oil will offer more wear protection for his flat tappets than 800 ppm P of ZDDP in an SN/GF-5 oil, well...

Anyway, Jim, I have no hard feelings here -- I was just frustrated by your seemingly argumentative responses. smile
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 01:21 AM

Originally Posted By: Gokhan
See this reference for the understanding of the ACEA categories.

I am familiar with the ACEA sequences. I would suggest you do have to look at the B as true diesel categories, and not all oils meet ACEA specifications. PYB certainly does not. Pennzoil certainly has a different bar to meet when it's dealing with PYB versus PU in A5/B5 or A3/B4 types. Heck, we even have people using ACEA E rated oils in various VW diesels that call for VW spec oils.

With respect to my Infiniti, "luxury car" or not, its oil specifications are very modest. It calls for SM/GF-4 in North America, with a bit wider range elsewhere. Generally speaking, the engine isn't calling for anything too terribly specific, like a certain phosphorous or SAPS content.

I'd be interested to hear from Doug or Shannow about the 15w-40 grades commonly used down under. I assume the 15w-40 commonly used in gassers there is dual rated like most 15w-40 grades here.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 01:26 AM

Another issue, aside from ZDDP, is viscosity. Some of these engines were contemporary with a 10w-30 with a higher HTHS than what one sees in an ILSAC rated oil. Aside from ZDDP, some people do choose an HDEO over a PCMO for certain applications due to the higher HTHS, without having to jump to a 10w-40, 20w-50, or a synthetic in the process.

Personally, I never had issues with ILSAC rated oils in older stuff unless there were serious fuel dilution issues.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 01:47 AM

Originally Posted By: Garak
Originally Posted By: Gokhan
See this reference for the understanding of the ACEA categories.

I am familiar with the ACEA sequences. I would suggest you do have to look at the B as true diesel categories, and not all oils meet ACEA specifications. PYB certainly does not. Pennzoil certainly has a different bar to meet when it's dealing with PYB versus PU in A5/B5 or A3/B4 types. Heck, we even have people using ACEA E rated oils in various VW diesels that call for VW spec oils.

With respect to my Infiniti, "luxury car" or not, its oil specifications are very modest. It calls for SM/GF-4 in North America, with a bit wider range elsewhere. Generally speaking, the engine isn't calling for anything too terribly specific, like a certain phosphorous or SAPS content.

I'd be interested to hear from Doug or Shannow about the 15w-40 grades commonly used down under. I assume the 15w-40 commonly used in gassers there is dual rated like most 15w-40 grades here.

I was primarily pointing out that the equivalent of API CJ-4 is ACEA E9, not ACEA Bx.

I don't think ACEA licenses A and B categories separately any more -- they all seem to come as A/B combined at the present. ACEA Bx is possibly more similar to the old API CF. It's certainly not meant for heavy-duty engines as the API Cx-4 or ACEA Ex categories.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 01:58 AM

Originally Posted By: Garak
Another issue, aside from ZDDP, is viscosity. Some of these engines were contemporary with a 10w-30 with a higher HTHS than what one sees in an ILSAC rated oil. Aside from ZDDP, some people do choose an HDEO over a PCMO for certain applications due to the higher HTHS, without having to jump to a 10w-40, 20w-50, or a synthetic in the process.

Personally, I never had issues with ILSAC rated oils in older stuff unless there were serious fuel dilution issues.

xW-30 oils with higher HTHS values are nothing but xW-35 oils. Both the KV @ 100 and HTHSV are about 15% higher than a typical xW-30, with the same proportional increase -- so, an xW-35 so to speak.

I wouldn't be that picky about viscosity and if the manufacturer recommended such an oil ("xW-35" so to speak), I would pick xW-40 in the case of a diesel engine or flat-tappet engine (because of wear concerns) and either the xW-30 or xW-40 for a modern gasoline engine depending on driving style and particular engine. For gasoline engines, if wear is not a concern, I like smaller viscosity because of lower (= better) oil pressure, better fuel economy, and more compliance with the various GF-5 specs.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 02:01 AM

Certainly. The E sequences are based upon the API specifications, which certainly isn't the case with the A and B sequences, and no, I'm not aware of any pure "A" or pure "B" oils, either. But, if an oil is likely to be used in a European diesel of some sort, and, specifically, meets the minimum specifications, there are obviously standards to be met that other, non-ACEA oils may or may not meet - we just don't know.

I think we in North America focus way too much on the differences between HDEOs and ILSAC stuff, rather than the similarities. CAFE's legacy isn't so much thinner oils or reduced phosphorous content, but a lot of alarmism about the differences between a "gasoline" oil, an HDEO, and a "motorcycle" type oil.

It's great that we can use a thinner oil in a gasoline engine without adverse consequences. It's also important that such oils are marketed appropriately to ensure someone doesn't toss them into his new Cummins. On the other hand, just because it says "Rotella" doesn't mean it's relegated to the big rigs.

You want a real kick in the head with respect to pricing? Our wonderful Walmarts charge about twice as much for M1 TDT as the distributor charges for Delvac 1. Go figure.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 02:06 AM

Originally Posted By: Gokhan
I wouldn't be that picky about viscosity and if the manufacturer recommended such an oil ("xW-35" so to speak), I would pick xW-40 in the case of a diesel engine or flat-tappet engine (because of wear concerns) and either the xW-30 or xW-40 for a modern gasoline engine depending on driving style and particular engine.

I wouldn't be, either, necessarily, but I could see why others would. Some would be deathly afraid of a 15w-40 as too thick. They would prefer to use a 10w-30 HDEO as still within grade for their vehicle that originally called for 10w-30.

On that vein, my dad was into thin before it was in. I was considering running a 5w-30 HDEO in my LTD at the time (it was consuming 5w-30 PCMO heavily, and with our weather, just jumping up grades isn't necessarily wise). He made it very clear of what he thought about using that "thick stuff" in there. wink
Posted by: Jim Allen

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 10:29 AM

I spent some time this morning rereading the relevant parts of both the referenced texts above, the SAE and the Dutch book referenced later in the the thread, and I'm beginning to think I didn't give the ZDDP differences between an HDEO and a PCMO enough weight in the context of a flat tappet engine.
Further reading in Noria texts and others (I have an "HDEOs in gassers" file) tends to reinforce this, though when dual rated HDEOs are compared to PCMOs, the cautions are much less strident vs a diesel-only rated HDEO vis-a-vis detergency. The detergency seems to be the most significant issue.

HDEOs seem to be a better choice in really old engines (flat tappet or otherwise) that lack filtration, or at least full flow filtration, because the detergency and dispersancy qualities of an HDEO are much more useful in that type of crankcase environment.

At the end of the day, while I think an HDEO has "enough" anti wear protection for most flat tappet engines, it may be less near optimal than I originally thought. We have no real way of knowing one way or the other until someone does some wear tests or we get inside info from an oil manufacturer. Prudence would then dictate going with the more suitable oil, especially in a muscle car engine. So I think I'm going to say, "I stand corrected" here.

As to the question originally asked ( see the red highlighted part below), at the risk of continuing to be argumentative, I still think the general answer to that is "yes." HDEO's have "enough" wear protection generally speaking. We know that to meet SM specs, an HDEO has to have the wear protection to go with it. For the most part, the lube mfrs think SM and SN is backwards compatible into the flat tappet era, so an HDEO is AT LEAST at that level. Without knowing the exact ratio of primary to secondary ZDDP, etc. or actual wear tests, I can't say definitively what the end results might be but I suspect the HDEO would show less wear than the average SM or SN PCMO in a standard performance flat tappet engine.

"Hey all... I was wondering if today's CJ-4 HDEO lubes have enough anti-wear additives to protect older engines with flat tappet cams? I know that the CJ-4 HDEO's have reduced amounts of certain additives compared to older CI-4 version. I got asked this question today by a friend who has an older muscle car with a flat tappet motor. He was told that he should still run a ZDDP additive with a current CJ-4 lube if he chooses to run a diesel motor oil. Are CI-4 oils even available anymore besides from Amsoil?
Posted by: OVERKILL

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 11:01 AM

Originally Posted By: Jim Allen
I got asked this question today by a friend who has an older muscle car with a flat tappet motor. He was told that he should still run a ZDDP additive with a current CJ-4 lube if he chooses to run a diesel motor oil. Are CI-4 oils even available anymore besides from Amsoil?


he's probably better served with an oil like M1 0w-40 which is setup with a higher level of AW additives and is also a PCMO IMHO.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 12:49 PM

Originally Posted By: Jim Allen
I got asked this question today by a friend who has an older muscle car with a flat tappet motor. He was told that he should still run a ZDDP additive with a current CJ-4 lube if he chooses to run a diesel motor oil. Are CI-4 oils even available anymore besides from Amsoil?

I think the concern over something with flat tappets and very high spring pressures might be warranted. For something of a more modest output, I wouldn't worry. I do recommend VR1 fairly often and for good reason. Beyond that, with the really high performance stuff, there are boutiques and dedicated race oils, of course. And none of us here, to my knowledge, claimed that HDEO was interchangeable with a race oil or ideal for flat tappets with very high pressures.

And you know my stance on additives. They're a last resort. I did use a ZDDP additive for break in of the F-150 after rebuild, but that's simply because I had no desire to use 20w-50 VR1 for a winter rebuild (the 10w-30 is rare here) and there simply weren't a lot of other options at the time; even Defy was just ink on a press release.

I still contend that the detergency issue with HDEOs is overblown. Soot carrying capability did go up with CJ-4, but TBN and SA have trended down, generally speaking. Take a look at the elemental VOA numbers and TBN of M1 0w-40, Mobil Delvac 1 5w-40 (CI-4), and Mobil Delvac 1 ESP 5w-40 (CJ-4). Detergency (from the elemental perspective, which is all we can see in a cheap VOA, of course), SA, and TBN all go down as me move from M1 0w-40 to the CJ-4 Delvac 1. The TBN drops further if you go to something like Delvac 1 ESP 0w-40, which lacks the higher minimum TBN ACEA standard of the 5w-40.

And we shouldn't allow ourselves to fall into the trap of ignoring what we can't see, either. Delvac 1 LE 5w-30 is CJ-4 with what are roughly GF-5 levels of phosphorous. Obviously, something else is fulfilling the ZDDP's role there. And, soot holding has improved while elemental detergents and TBN have dropped.

Oils are compromises, and detergency versus anti-wear is not a new issue. Should we go one step further and return to ND oils? Is Pennzoil's clean engine campaign going to leave a bunch of premature engine failures in its wake? I'm not concerned. As I already mentioned, the Delvac 1 ESP 5w-40 sheet endorses its use in high performance gasoline applications, specifically. In my use, I'm not concerned about ZDDP in any event.

Doug has gone through this Delvac 1 in a gasser argument before, and I wouldn't be surprised in the least that he doesn't wish to go through it again. There are too many deaf ears out there. I, however, am glad to be able to learn from his decades of experience at the pinnacle of the industry and put some of that knowledge into practice in my own way.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 07:28 PM

I think we all agree that a CJ-4/SM oil is usually OK to use in a gasoline engine, assuming the recommended viscosity is available. As I said earlier, I used Mobil Delvac 1300 Super 15W-40 CJ-4/SM for many years in my small gasoline engine. The main drawback was excess drag on the engine, making idles, especially cold idles, rougher and the fuel economy a little less and light-throttle power a little less. The excess drag is caused by the high viscosity (internal friction of the oil) and higher surface friction of the oil in comparison to an ILSAC GF-x (Energy/Resource Conserving) oil.

My main point in this thread is that, after educating myself reading the SAE Lubricant Reference and a couple of other references, higher ZDDP limit in CJ-4 oil (1200 ppm P vs. 800 ppm P in ILSAC GF-x oil), is not to make a CJ-4 oil more wear-protecting than a GF-x oil. It's only to make up for the detergents and dispersants in the CJ-4 oil. If you have 1200 ppm P, it's effectively much less because of the detergents/dispersants in Cx-4 oils. There is a lot of buzz on the Internet for using Cx-4 for flat tappets because of high ZDDP, but they are ignorant of this very important technical reason why the ZDDP is higher in diesel oil. That's my main point and I didn't realize this myself until I read the references.

I do agree that CJ-4/SM oils pass the gasoline-engine wear tests Sequence IIIG and Sequence IVA and they should usually be OK in a gasoline engine.

Also, the issue regarding primary vs. secondary ZDDP, the latter of which is far more potent as an antiwear additive, may be somewhat less of a concern, as nowadays they seem to mostly use a mix of the two and the mix seems to have similar potency of secondary ZDDP alone. (In the past diesel engines used only primary ZDDP because of better thermal stability of it.) So, perhaps, this is not too big of an issue but then it may also be. Some gasoline-engine oils may take more advantage of higher secondary-ZDDP ratios in the ZDDP mix than diesel-engine oils can accept.

Garak, you pointed out that the detergent levels have been decreasing in Cx-4 oils. However, notice that ZDDP levels have also been decreasing. The reason why they used more ZDDP in CI-4 was to make up for the rather high concentration of detergents in CI-4. The reason why some of the CJ-4 formulations use even less ZDDP is because they use even less detergents. So, someone shouldn't get sucked into a CI-4 oil for flat tappets because it has more ZDDP, as it's only to make up for high detergent content. In fact, the wear-protection requirements in CJ-4 or stricter than in CI-4.

What's also very important is the dispersants in diesel oil. CJ-4 in particular has a very high concentration of dispersants as CJ-4 has unprecedented soot control. These dispersants are ashless (metalfree) and they don't show in specs or VOAs. They are called succinimides. They also fight against the ZDDP films. See this very recent (September 2013) scholarly article (full text not available for free):

Abstract: Recent years have seen an increase in the concentration of dispersant present in formulated engine oils, while the concentration of antiwear additives has been progressively reduced. However, it is known that the presence of dispersant can, in some cases, detract from the performance of antiwear additives in lubricant blends. In this article, the influence of three succinimide dispersants on the film formation and wear-reducing properties of a secondary zinc dialkyldithiophosphate (ZDDP) has been studied. Both posttreated and non-post-treated dispersants reduce steady-state ZDDP tribofilm formation to a certain extent depending on the dispersant concentration. At very high dispersant concentrations, ZDDP film formation is suppressed almost entirely. This can be restored only marginally by increasing ZDDP concentration, which implies that the absolute dispersant concentration rather than the dispersant : ZDDP ratio controls the impact of the dispersant on ZDDP film formation.

Addition of dispersant to ZDDP also caused an increase in wear rate for all three dispersants tested. For one succinimide reported in detail in this article, it is has been shown that the wear rate increases approximately linearly with dispersant concentration and is largely independent of ZDDP concentration over the P weight percentage range studied.


So, moral of the story is that don't get sucked into heavy-duty (CJ-4, CI-4, etc.) oils just because of their high ZDDP content. Their high ZDDP content is only to make up for high concentrations or dispersants and detergents found in diesel oils. You won't get the same potency of a given amount of ZDDP in a diesel oil as you would get from the same amount in a gasoline oil with less dispersants and detergents. Effectiveness of ZDDP is greatly and inversely affected by the amount of dispersants and detergents in oil, and diesel oils have a lot of dispersants to control harmful soot.
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 07:48 PM

Originally Posted By: Gokhan
So, moral of the story is that don't get sucked into heavy-duty (CJ-4, CI-4, etc.) oils just because of their high ZDDP content. Their high ZDDP content is only to make up for high concentrations or dispersants and detergents found in diesel oils. You won't get the same potency of a given amount of ZDDP in a diesel oil as you would get from the same amount in a gasoline oil with less dispersants and detergents. Effectiveness of ZDDP is greatly and inversely affected by the amount of dispersants and detergents in oil, and diesel oils have a lot of dispersants to control harmful soot.

In addition, more generally than for flat-tappet engines, I also don't see much of an advantage of using a CJ-4 oil (heavy-duty engine oil) in a gasoline engine in general, as there are a vast variety and number of gasoline-engine oils, more tailored and better tested toward gasoline engines, using gasoline-engine specific additive packages. A CJ-4/SM oil will probably work OK in most gasoline engines given the availability of viscosity, but then why use it just because it's OK to use, as it's not optimized for gasoline engines but for diesel engines?
Posted by: Gokhan

Re: CJ-4 oil for older flat tappet engines.. - 01/08/14 07:58 PM

Originally Posted By: Garak
With respect to my Infiniti, "luxury car" or not, its oil specifications are very modest. It calls for SM/GF-4 in North America, with a bit wider range elsewhere. Generally speaking, the engine isn't calling for anything too terribly specific, like a certain phosphorous or SAPS content.

In that case, why not use a cheap conventional 5W-30 GF-5 or perhaps a cheap fully synthetic 5W-30 GF-5 in your Infiniti? Your car (smoother idles) and your wallet (less money spent on fuel) will both thank you. Do you really need to run xW-40 in it (racing it etc.)? I can understand that you can get the Delvac 5W-40 cheaper than the Mobil 1 0W-40 or similar if that's the case.
Posted by: Garak

Re: CJ-4 oil for older flat tappet engines.. - 01/09/14 03:56 PM

As mentioned already, I wouldn't call an HDEO interchangeable with a break in lube, a pure racing oil, or VR1. It is, however, another very good option for various circumstances. I wouldn't recommend that someone building a performance engine go and grab it and use it for break in. On the other hand, I'd have absolutely no hesitation about using it in my F-150. Additionally, 15w-40 got a lot of use in the old Audi, as it was the widest recommended viscosity. People who do have flat tappet high performance engines should be cautious, particularly at break in. But, the guy driving an old slant six or a Ford 300 doesn't need to go and buy a racing oil or VR1 20w-50.

In older engines, too, there are other things we have to consider. An older engine can benefit from detergency, either from an HDEO or a modern GF-5 oil. In carbed applications, fuel dilution is certainly a possibility. In my F-150, it was terrible before the rebuild and carb replacement. To maintain operational viscosity, I had to use 15w-40 (for the summer) or a non-ILSAC PCMO (MaxLife 5w-30, non-ILSAC at the time). Otherwise, the oil light would come on.

While not all carbed engines were as terrible, we have to be cautious when comparing a carbed example versus a modern fuel injected system. The introduction of fuel injection probably did more to extend OCIs than most other advancements. We shouldn't underestimate the issue of fuel dilution; look at some of the DI examples we see today.

When it comes to detergency competing with anti-wear, we see oil companies trying to strike a balance. This is nothing new. After all, break in lubes and racing oils have little to no detergency for a reason.

Note the GF-5 oils aren't exactly light on the detergency. I would say that few of us here are equipped to determine whether a GF-5 or an HDEO or a racing oil has the best anti-wear properties for a given situation, unless that situation is really obvious (i.e. GF-5 in a new flat tappet race engine is silly, and race oil in a taxi is pretty foolish). Generally speaking, though, to determine which (between a 5w-30 SN/GF-5 and a 10w-30 HDEO) would provide the best anti-wear in my F-150 or (between a 5w-30 SN/GF-5 and M1 0w-40 and Delvac 1 5w-40) my G37 would require a serious undertaking.

I'm aware of the fuel economy issues when comparing a GF-5 rated lube (such as a 5w-30) versus something like a 10w-30 HDEO, 5w-40 or 15w-40 HDEO in something like my G. And yes, it's false economy to choose a thicker, yet cheaper grade. But, that's not exactly what it's all about. Walmart Canada is nuts, and I mean certifiably insane, and sometimes it's necessary to vote with one's wallet. Imperial Oil seems to reward HDEO purchasers, and again, it's necessary to vote with one's wallet.

For idle and performance, I don't notice a difference between the HDEO and the PCMO. I've already gone through the fuel economy in another thread here, not to show that there's no difference, but to show that it's unnoticeable. Yes, it's there. Yes, I would agree that it costs me more gas. But, from an operational perspective, I wouldn't notice an oil switch unless it were 20w-50 in our -40 or something similarly odd.

With respect to ILSAC type lubes, I have nothing against them. I used about 500 bottles of QS conventional in a 1981 Impala over the years alone. That's one taxi out of many. My LTD went half a million kilometers and only saw QS and GTX. My Town Car was similarly treated. I simply had some Delvac 1 ESP in stock, and tried it. I may want to run some UOAs for the heck of it. I may want to stick with it, given the pricing. Of course, my mixing phobia is well known here. If I have Delvac 1 in there, I have to stick with it until I'm sick of it. wink

But, I hold no illusions. I would have an exceedingly difficult time proving that this choice is "better" than Formula Shell, PYB, QS, M1, Mobil Super, Valvoline, GTX, or whatever alternative we wish to pick.