Flat Tappet Motor Oil One More Time

Status
Not open for further replies.
Joined
Apr 30, 2017
Messages
139
Location
Michigan
I just discovered the 540RATBLOG on motor oils. His testing shows that high zinc/phosphorous motor oils may not be the best indicator of protection for flat tappet engines. The testing on wear judged by psi breakdown shows that some oils without the 1,000+ zinc levels are better than those with. Basically, the zinc/phosphorous levels are irrelevant. Is there anything wrong with his analysis? Any reason to doubt it? If its for real, then why not pick one of the top ten or twenty oils and not worry about the on-going reductions in zinc and phosphorous? Any thoughts? I am not a chemical engineer so I can't comment on the validity of the tests so that is why I am asking this forum.
 
It's been discussed here at length. There are issues with his test protocol mainly that his test rig doesn't accurately model the cam/lifter interface or any interface in an internal combustion engine.
 
Search on 540RAT and you'll get hours of reading.

You need enough ZDDP, but since there are like 16 different formulation of ZDDP, he can't tell you which he's testing and which didn't work the best.

There is much more going on inside an engine than just the cam/lifters. Although they are crucial. Literally million and millions of flat tappets have run fine on Jiffy Lube bulk oil.

Race motors are whole nuther thing. Need specs and build info before commenting there ...
 
The engines in my cars are either low mileage original, never opened; or rebuilt to as close to manufacturers specifications as possible. 1966 Mustang 289 2V, 1972 Plymouth 440 4V, for example. They are not hot rod engines, nor are they race engines. They are totally stock and for the rebuilt ones, as close to stock as possible. Thanks.
 
Even if his methodology is wrong, does his answer make sense? That there is more to preventing flat tappet cam wear than just zinc, or is it that zinc levels matter what other anti-wear chemicals may be in the oil?
 
Originally Posted By: Building3
The engines in my cars are either low mileage original, never opened; or rebuilt to as close to manufacturers specifications as possible. 1966 Mustang 289 2V, 1972 Plymouth 440 4V, for example. They are not hot rod engines, nor are they race engines. They are totally stock and for the rebuilt ones, as close to stock as possible. Thanks.

Probably Valvoline VR1 10W-30 would be a great oil for both, it has 1300ppm of Zddp so no worries abotu Zddp, a stock engine anyway specially one that is already well worn in doesn't need crazy high concentrations of Zddp..
 
Originally Posted By: Building3
Even if his methodology is wrong, does his answer make sense? That there is more to preventing flat tappet cam wear than just zinc, or is it that zinc levels matter what other anti-wear chemicals may be in the oil?


This is what I always argue. A Pennzoil engineer (for example) could defend Pennzoil in a court of law that Pennzoil's additive package protects at least as well or better at, say, half the zinc level that oils had decades ago when you view the additive package in it's entirety.

If low zinc oils were fatal to flat tappets, wouldn't major oil companies place a warning label on their newer generations of oil to avoid a class action lawsuit from people using it in older cars? There are tens of millions of flat tappet cars still out there on the road. Toyota to this day still manufactures bucket and shim overhead cam engines, don't they? Buckets and shims are flat tappets in my book. It seems like all this obsession about zinc levels is a little overdone.
 
Originally Posted By: FordCapriDriver
The 540RAT page is not the word of god himself, in fact as others have said his tests and his results are not the best guide.

It is far worse than just "not the best guide", actually it is no guide at all. His premise is wrong, his testing methodology is wrong and worse of all, his data presentation and conclusion is even more wrong.

For the OP here is some reading:

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4344412/1

https://bobistheoilguy.com/forums/ubbthreads.php/topics/4533661/1

The bottom line is that when properly presented, all the results from his "test" are statistically equal. There is no discernible difference between any of the oils he tested, therefore all of them should be ranked equal. Or not ranked at all if you really want to be truthful.
 
Originally Posted By: Scdevon
If low zinc oils were fatal to flat tappets, wouldn't major oil companies place a warning label on their newer generations of oil to avoid a class action lawsuit from people using it in older cars? There are tens of millions of flat tappet cars still out there on the road. Toyota to this day still manufactures bucket and shim overhead cam engines, don't they? Buckets and shims are flat tappets in my book. It seems like all this obsession about zinc levels is a little overdone.

Is there any evidence at all that flat tappet engines require high zinc levels after break-in?
 
Originally Posted By: kschachn
Is there any evidence at all that flat tappet engines require high zinc levels after break-in?


My guess is that you already know the answer to your own question. Which is kind of different that you're asking it in the first place. Not just in this thread but many, many others as well.
 
Originally Posted By: SatinSilver
Originally Posted By: kschachn
Is there any evidence at all that flat tappet engines require high zinc levels after break-in?

My guess is that you already know the answer to your own question. Which is kind of different that you're asking it in the first place. Not just in this thread but many, many others as well.

Not at all, I do not know. In many threads I have seen people assume it is required, but I've also seen posts where it is stated that the requirement is only for break-in.
 
Originally Posted By: kschachn

Is there any evidence at all that flat tappet engines require high zinc levels after break-in?


Obviously some zinc is needed and it's just accepted that SOME zinc in engine oil is beneficial even after break in.

I used the Toyota bucket and shim example a few posts ago. What does Toyota do at the factory to "Break In" their buckets and shims and cams? (Nothing). I don't even think Toyota even uses assembly lube in their engines other than just regular engine oil. What procedure did GM use in 1970 to "break in" an LS6 camshaft in a Super Stock engine with .520 total lift / 316 duration? (Nothing other than maybe some zinc-rich assembly lube).

They certainly didn't hold the throttle at 2000 RPM for 20 minutes on the assembly line in 1970 on an LS6 Chevelle.
 
High lift, aggressive ramp, long duration-or '70s-'80s factory GM camshaft! Only ones I've ever had trouble with were GM ones from that era, back when every oil had high ZDDP levels.
 
The whole drama about flat tappet engines is just that-- drama. A true flat tappet engine is so rare these days that the number of people who actually got one of those engines is about 1% of people who think they got a flat tappet engine. Those with actual non-hydraulic (solid) flat bottom (splash/drip lube) litters can run all the fancy $$$ designer brand oil they want and they will still be replacing cams and lifters. ZDDP will not solve that problem, no matter what sort of ZDDP it is. For those very few with actual stock setup flat tappers, careful monitoring of RPM (don't over-rev too much) will do more than any oil ever could or can to prolong life of cam/follower.
 
Last edited:
Originally Posted By: silverbar
Those with actual non-hydraulic (solid) flat bottom (splash/drip lube) litters can run all the fancy $$$ designer brand oil they want and they will still be replacing cams and lifters. ZDDP will not solve that problem, no matter what sort of ZDDP it is.


What's the difference between a hydraulic and solid lifter in terms of cam lubrication, all other engine geometries being equal ?
 
Status
Not open for further replies.
Back
Top