15w-40 in a 2-stroke?

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So I'm taking advantage of Mobil's rebate on HD Super Delvac 1300 15w-40 oil. I visited the Mobil website to check out the product info and noticed that the Delvac 1300 has a CF-2 rating for use in a two-stroke engine. I emailed Mobil about it and they said while it is preferred to use a monograde oil, the 15w-40 can be used as well. Only time I've heard of that. http://www.mobil.us/USA-English-LCW/heav...-super.aspx#at.
 
Hi,
sdan27 - Yes 15W-40 CF2 rated lubricants can be used in DDs (not in 149 engines, or any Marine application) to improve startability from 0F to -25F. SAE30 is preferred

The 15W-40 lubricant must have a HTHS vis of 3.7cP min, TBN 7 min, and should be for a "short term" use
 
Originally Posted By: sdan27
So I'm taking advantage of Mobil's rebate on HD Super Delvac 1300 15w-40 oil. I visited the Mobil website to check out the product info and noticed that the Delvac 1300 has a CF-2 rating for use in a two-stroke engine. I emailed Mobil about it and they said while it is preferred to use a monograde oil, the 15w-40 can be used as well. Only time I've heard of that. http://www.mobil.us/USA-English-LCW/heav...-super.aspx#at.


A two stroke heavy duty diesel motor is what they mean, aka Detroit Diesel. Not like your chainsaw or weedeater. 15w40 will not mix well with gasoline
wink.gif
 
I did realize they were referring to the old DDs. We run three of them on our farm. A 3-53 in a trencher we lay tile mains with, a 4-53 in a crane and a 6-71T in an OshKosh truck we converted to a lime spreader. We use all of these exclusively in the summer months so I run a 40w oil in them. I was thinking if there were a 15w-40 oil that would work, that would be nice because then I could use that in all our equipment and wouldn't have to buy the straight 40w special.
 
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The cylinder ports DESTROY any viscosity improvers that a multigrade oil uses to achieve the viscosity spread between the W viscosity and the summer viscosity. The worst shear ever!
 
Originally Posted By: bullwinkle
The cylinder ports DESTROY any viscosity improvers that a multigrade oil uses to achieve the viscosity spread between the W viscosity and the summer viscosity. The worst shear ever!

Mobil Delvac 1300 Super 15W-40 is CF-2 approved, meaning that it was tested in a standard two-stroke-cycle test engine and it passed the test. Therefore, it would provide sufficient protection, although not the best protection, for a two-stroke engine.

Incidentally API has now ditched both the CF-2 and CF tests for good. They no longer manufacture CF-2 test engines.
 
Originally Posted By: bullwinkle
The cylinder ports DESTROY any viscosity improvers that a multigrade oil uses to achieve the viscosity spread between the W viscosity and the summer viscosity. The worst shear ever!


Very interesting!

I love this site, just because I can learn things like this almost every day.
 
Viscosity improvers have changed over the years.

Are we still blending 15w40 the same way from 30 years ago?

And if HTHS is the issue, then there are plenty of multi-weight oils with HTHS >3.7! I guess maybe 40 years ago the only way to get HTHS was with a straight single weight.

Times have changed.

Except for some massive oil con$umption, and using the cheapest oil for top offs, is there any REAL proven reason not to use a current 15w40?
 
Hi,
unDummy - Yes there are many design issues with DD two stroke engines - and many variations too!

Typical oil use is around 1ltr/1kkms and they do leak a lot. As well as being scavanged by a supercharger many variations are twin turbocharged. Early versions revved out to near 4000rpm and later fuel economy versions operated around 1600rpm!

I aa a great fan of this great American motor and have been involved with them since the 1950s - in boats, trucks, Euclid twin engined scrapers, Champion graders, Terex dozers and the likes. I managed the largest Fleet of these engines outside of NA at one stage - and Test drove a prototype fuel economy version in the US in 1975! I also operated the first EFI version (DDEC 1) here in OZ in 1986-7 and assisted in refining them for use in out Trucking Industry

The sound of course is an engines designers delight - well at least to people like me

Roger Penske killed their "costly" production in favour of the Series 40, 50 and 40 Series

Never use other than prescribed lubricants in these engines!
 
Mobil Delvac 1300 Super 15W-40 has an hefty HTHS viscosity of 4.3.

It is CF-2 certified, unlike other multigrade HDEOs. You can't certify an oil without running it in a prolonged period in a test engine. This means it works in a two-stroke engine. Whether a monograde will perform better (possibly, perhaps even likely) is another question.

Motor oil, including viscosity modifiers, has evolved a lot, and you can't judge an oil simply by saying that it's a multigrade and it won't work and so on. It's not even unlikely that some generic 40-weight oil will actually perform worse in a two-stroke-cycle diesel engine than 1300 Super 15W-40.
 
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Here is a good discussion on multigrade vs. monograde in two-stroke-cycle diesel engines. In any case the most important thing is to make sure that the oil has CF-2 certification if this certification is required by your engine manufacturer.
 
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Thanks for the heads up Doug, but my question wasn't answered.

Today's oils are far superior to what was available 5 years ago, let alone 40 years ago.

Today's VII/VM's are far superior to what multi-weights were blended with back then too. If its simply a VII/VM issue, then I'm not worried. If its something else, I haven't seen it.

I haven't seen an issue with non-SAE40 in the gensets, pole/well drills, pumps, and trucks that were topped off regularly and filled with 15w40 in long term use. I've also seen some regularly topped off with 20w50 and 10w40, because that was what was available at the local nearest store. Any oil is better than none and there were no ill effects. Not every fleet or garage keeps barrels of every oil weight out there so I'd guess that the mis-oiled engines are more than what is spoken about on the web.

I understand the consumption issue and its not a concern.

There are plenty of >3.7 HTHS oils out there. SAEJ300 for a 15w40 20w40 25w40 and straight-40 requires it. The 0w40, 5w40, 10w40 requires 2.9 HTHS which probably would be sheared and consumed excessively. Some are >3.7 too if you hunt down and read the datasheets. And, the winter oil, per J300, 30wt HDEO requires a 2.9 HTHS. Makes you want to think that unwarranted 'fear' of 'nothing' is the only reason to stick with the SAE40.

I think that the shear stable DexronVI and ATF+4(over a decade ago), along with the performance seen from current oils, shows that we can make an oil with the VII/VM's work fine in ANY application.

I wonder where brightstock/slackwax would be on the chart here(maybe too far to the left and off the chart):
http://www.lubrizol.com/ViscosityModifiers/Asteric/default.html
 
Hi,
undummy - You and I both know of the advances in lubricants over the last several decades

My answers were predicated to the OP's question - I assumed that he was talking about the DD two-stoke engine series range

DD two-stroke engines have not been developed for around 20 years, their genesis commenced in the 1930s. Yes, you can use a 15W-40 HDEO under certain operating criteria and that has been the case for many years. Long term use however is usually costly! However even after production ceased DD made sure that mono-grades were covered in their Recommendations. The same applied when Mercedes Benz took over DD!

What makes the DD specific lubricants a better choice is the long well developed formulation history for each Brand. This is typically 0.8% SA (which creates a low TBN), low VI with good viscosity retention and excellent foaming and corrosion controls

In many applications these engines operate for long periods at WOT - in others (buses etc) they idle for long periods. They need lots of clean air for scavanging and will tolerate high Fe levels. They are intolerant of high soot loadings (less than 1%) and fuel above 2.5%. They operate well in the most difficult of climates. In my case I have used them at very high altitudes (10000ft) and at the extremes of cold -25C and in searing heat above 110C. We never ever used a 15W-40 lubricant but an SAE30 instead in the cold!

IME I would never use other than a recommeded viscosity and correctly formulated lubricant in these engine families - but to each his own!
 
I will say this discussion has convinced me to use Delvac 1300 in my older Mercruiser flat tappet V8 (351 Windsor Ford)-if it can begin to stand up to a DD 2-stroke, it'll definitely be OK in continuous gasoline 4-stroke operation. Still would stick to monograde oils in the DD, though, there are plenty of reasonably priced ones available, such as Rotella T1 SAE 40.
 
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