Flat tappet cam wear due to reduced zinc/phos

WaterfordBob · May 27, 2006

Excess flat tappet cam wear was a topic in the June Hot Rod Magazine. This seems to be a relatively new rash of failures. But in typical politically correct form they just threw out a bunch of possibilities but no clear direction. The list of possibilities included recent (since 2000) influx of import tappets with poor crown, poor metalurgy, etc. But the main theme was the reduction in phos and zinc in the additives of catalyst friendly modern oils. Granted the lube needs of a roller tappet/cam are different but it's still very very high loading on the cam.
So does anybody know the real scoop so that us drivers of older nostalgic cars with the flat tappets can treat our babies right?

JohnBrowning · May 27, 2006

Who uses import lifters??? I always TRW,Crane,Comp Cams,Lunati,OEM,etc...... If someone is skimping on lifters due to cost they need to rethink what they think they are saveing!!!!

More then likely it is the lower levels of ZDDP, lack of a good assemply lube with EP additives and failure to stay above 2000 RPM's the first 20 minutes of run-in.

Quest · May 27, 2006

JohnBrowning has a good point.

Flat tappet lifters doesn't have to go on high ZDDP level in order to survive. Any of those previously reported incidents are mainly isolated incidents (mishaps) due to the following:

In the 80s, GM suffered from flat tappet wear due to quality issues and although they officially denied it's their fault, insider's source leaked indicated that their OE parts supplier didn't harden their cams enough to deal with this. This was subsequently (silently) resolved with hardened cam/lifter parts.

Also: some cheep imported aftermarket replacement cams and lifters are not properly hardened and this may not be immediately noticeable until 30,000miles down the roard.

Lastly, this is due to improper initial breakin procedure. John is absolutely right that in addition to have sufficient assembly lube on the contact surface, builders often neglect the importance of running them 1600~2000rpm for up to 10 mins during initial run-in stage.

Q.

LarryL · May 27, 2006

Current Hot Rod magazine has an article about this very subject, short but a good read.

G-MAN · May 27, 2006

quote:

Originally posted by LarryL:
Current Hot Rod magazine has an article about this very subject, short but a good read.

BrianWC · May 27, 2006

This reminds me of the "typical forum thread" joke that went around a little while ago.

waynebo · May 27, 2006

This has nothing to do with the chevies from the 70's that wiped lobe's etc...this a new problem that has been talked about by racers on most race sites and even hotrod has done an article on it.. it has to do with epa requirements and no longer a need in newer engines for the same compounds i.e zinc,etc. used in older flat tappet engines,,also the cam grinders,,top names have been having to get there lifters from crappy offshore suppliers as all american lifter manufacturing had come to an end,,johnson is supposed to be back now,,i hope...waynebo

BrianWC · May 27, 2006

This one:

http://theoildrop.server101.com/cgi/ultimatebb.cgi?ubb=get_topic;f=43;t=000867#000000

It was a good article, btw.

waynebo · May 27, 2006

After the base oil has sheared or squeezed out, The last line of defense is an additive that puts down a barrier film. This additive usually has higher levels of strength against shearing so it helps keep the wear down. Alright, here's the catch. In 96, the lubrication industry changed from the SH to SJ API rated oil by reducing the barrier lubricant additives to help preserve cat converters on cars. Why?, It appears that the manufactures / lubrication experts are concerned with contaminating the cat converters with the standard antiwear additives in the motor oils so they have reduced the levels of antiwear additives to preserve the cats. Hmmm, guess what, When they introduced the new SL GF-3 oils, They left it the same. Ok, not out of the woods yet... Now the new GF-4 oils are in the works in hopes to be introduced next year around April. Have a guess one of the things they are going to do?, YEP, reduce the current antiwear additives again.

BrianWC · May 27, 2006

Oh Wayne...NO offense, but I recommend a forum search to get caught up on the "new" GF-4 oils....which have been out a while.
This is only about the most or the second most talked about thing on BITOG.

Coral · May 27, 2006

quote:

Originally posted by WaterfordBob:
Excess flat tappet cam wear was a topic in the June Hot Rod Magazine. This seems to be a relatively new rash of failures. But in typical politically correct form they just threw out a bunch of possibilities but no clear direction. The list of possibilities included recent (since 2000) influx of import tappets with poor crown, poor metalurgy, etc. But the main theme was the reduction in phos and zinc in the additives of catalyst friendly modern oils. Granted the lube needs of a roller tappet/cam are different but it's still very very high loading on the cam.
So does anybody know the real scoop so that us drivers of older nostalgic cars with the flat tappets can treat our babies right?

Many of my gearhead buddies running 50-60's BowTie muscle use Amsoil 10-40 motorcycle oil. Dont get fooled by the term 'motorcycle" on the label. High Zinc and Phos included.
Synthetic 10W-40 High Performance Motorcycle Oil (AMF)
Formulated for maximum protection of motorcycle engines (liquid or air cooled, standard or V-twin), transmissions and primary chaincases. High levels of phosphorus and zinc provide maximum wear protection. Wet clutch compatible. Contains no friction modifiers. Anti-foam and viscosity stable for best possible overall protection. Performance specifications include: API SG/CF, JASO MA

Curious Kid · May 27, 2006

I'm a little surprised that no one mention to use a mixed fleet diesel oil like delo or rotella. To me, that would be easier to pour in than several qts of oil that's labled for motorcycles (a decade ago I thought about doing just that though). I'm just not that comfortibly in the know, you know.

BrianWC · May 27, 2006

Yeah, why waste money. Any good HDEO's gonna have the good stuff. Supertech even makes an HDEO 15W40.

427Z06 · May 27, 2006

To qualify for the SM/GF-4 rating, an oil has to pass the Sequence IIIG test. This tests consist of a Buick 3800 V6 retrofitted with pre-86'? flat tappet valvetrain, that is flogged at 125 bhp, 3,600 rpm for a 100 hrs with the oil temp held at 302°F. Maximum camshaft lobe plus lifter wear must average less than .0024".

Given this, I'm of the suspicion that most flat tappet cam failures are due to incorrect lubrication during breakin' (lack of a good assemply lube and engine prime, and failure to keep engine at 1600-2000rpm during initial run-in stage). However, since ZDDP is depleted with use, I can see where hi-po cams and springs may run into problems if anything but short (severe schedule) OCIs are employed. Here's where HDEOs may give you some insurance.

Rickey · May 27, 2006

427Z06 There is at least one difference. I'd be willing to bet my stash of GC that the Buick V6 used in the SM/GF-4 tests doesn't use anywhere near the seat and nose pressures that some racing flat tappet grinds use.

Coral · May 27, 2006

quote:

Originally posted by Curious Kid:
I'm a little surprised that no one mention to use a mixed fleet diesel oil like delo or rotella. To me, that would be easier to pour in than several qts of oil that's labled for motorcycles (a decade ago I thought about doing just that though). I'm just not that comfortibly in the know, you know.

What are we coming too!!??
Pouring diesal/motorcycle oil in our engines just to meet OEM specs of the particular build year specs

Either one really, I think the original question has been answered with either oil ( motorcycle/diesal has the makeup his ride needs)
Or of course he could utilize VSOT or SLOB and get those "nutrients" couldn't he.

Rodbuckler · May 27, 2006

I have been studying this problem for years, and I think it was caused by a combination of three things:

1. Aftermarket cam manufacturers came out with their most aggressive flat tappet grinds ever for both street and track. Lifter bore accuracy is critical when using the most aggressive lobes, as is break-in, oil selection, and valvetrain component selection.

2. Anti-wear additive levels were reduced in common car oils, yet people used them anyway in their performance engines. Lobes wiped shortly after the break-in period.

3. Poor metallurgy, surface treatment, or other manufacturing issues produced a product that was never going to survive regardless of the oil used.

ITSMR2U · May 28, 2006

Be careful with the motorcycle oils. An SG rated oil allows more ZDDP than current oils, but it doesn't mean that the manufacturer puts it in! Motorcycle Consumer News tested oils a few years back and found a few motorcycle specific oils (Golden Spectro for one) had less ZDDP than than many current automotive oils.

427Z06 · May 28, 2006

quote:

Originally posted by Rickey:
427Z06 There is at least one difference. I'd be willing to bet my stash of GC that the Buick V6 used in the SM/GF-4 tests doesn't use anywhere near the seat and nose pressures that some racing flat tappet grinds use.

First, how many people using these racing flat tappet grinds use 5w20 oil, and keep it at a constant 302°F for 100 hours of use?

Second, ZDDP levels in PCMOs has been limited by the .1% Phosphorus limit for over a decade. Current PCMOs (SM/GF-4) are now limited to .08% Phosphorus. So there hasn't been the drastic drop that some claim.

Third, the amount of ZDDP alone doesn't determine an oils ability to prevent wear. There's complex chemistry going on between the base stocks, add packs and other components that determine how well a particular oil will perform. (Note how well GC does for many, and GC's add pack looks relatively wimpy.)

Finally, move into the 21st century and start using roller elements in your valvetrain.

Coral · May 28, 2006

quote:

Originally posted by ITSMR2U:
Be careful with the motorcycle oils. An SG rated oil allows more ZDDP than current oils, but it doesn't mean that the manufacturer puts it in! Motorcycle Consumer News tested oils a few years back and found a few motorcycle specific oils (Golden Spectro for one) had less ZDDP than than many current automotive oils.

Yup. That is why they always specifiy the Amsoil stuff. And why I specified also. Good point though.

Flat tappet cam wear due to reduced zinc/phos

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