angel71rs

So I finally get around to reading the latest Car Craft and I see in the questions section that todays oils, for emissions device reasons, have much lower levels of zinc than oils in the past. So while they are great for roller cam engines, they put flat tappets/cams at greater risk of wearing out. Anyone heard this before?

They recommended racing type oils, which they say have greater levels of zinc. A lot of us run flat tappet cams in our 1st/2nd gens, so this zinc issue should be a high priority for us. Needless to say, I'm going to research the racing oils available and pick one with plenty of zinc in it for my next oil change on the RS.

85mikeTPI

Zinc levels can kill catalytic converters, so they have been lowered alot in
todays oils. On the good side, most diesel engine oils are still blended with
high zinc levels and can be used with good results in older motors also..

www.bobistheoilguy.com is a great resource for oil technology..

mike

Z28SORR

I don't know who wrote this but I think his credentials are in doubt. The zinc has been replaced by other anti-ware additives. And the cam. and lifter manufactures have not been living in a vacuum for the last 20 yrs.
It should be glaringly obvious that flat tappet system is going to have different ware charateristic than rollers, this doesn't mean there is any kind of an increased problem. And I sure wouldn't go around recommending that people with 1st Gens. use diesel oil.

DJ_951

I read the diesel oil idea in Car & Driver years ago. Talk to a oil expert and a major oil company about oils in general then asked about vintage car oil. Said diesel was best. Always used regular oil in the old '75, I quess diesel here I come.

I bet they sell it in the big jugs at wal-mart, syn-blend?

Sporter28

Lazer, Crower and Bullet cams recommend using off road oil with zinc and no synthetic oil until after break-in is complete. Lazer has a warning about the lack of zinc in modern oil on their website.

http://www.lazercams.com/

Another good oil site:

http://www.atis.net/oil_faq.html

angel71rs

The new additives are great for roller engines, but engines using flat tappets still need an additive that will protect at high pressure points, like the cam lobe/tappet contact point. Newer automotive oils just don't have this anymore due to the need to meet govt regulations for emissions equipment longevity.

Diesel oils still have the old additives, so they resemble automotive oils of the past. BUT... seems the govt is going after diesel oils too! They will have to meet new standards by 2007 in relation to emissions. Probably means hasta la vista to additives like zinc. So stock up on diesel oil now... OR...

I'm thinking on using a good synth + an additive high in zinc. Reaserach on bitog turned up this reply to a guy over there from the maker of CD2 Street Legal Oil Boost:


"Thank you for your interest in our CD-2 Street Legal High Performance Oil Boost. The average viscosity of this product at 100 C is 28 (cSt). Each bottle of CD-2 Street Legal High Performance Oil Boost typically contains by weight the following percentages:

Calcium: 0.78 %
Phosphorus: 0.43
Zinc: 0.47
Moly: 0. 0"

This is the next best thing to GM EOS at 4300 ppm phosphorus and 4700 ppm zinc!"

That kind of zinc boost should take address the problem for sure. And the stuff is supposed to be available at Big Lots for ~ 2 bucks.

Z28SORR

The warning on Lazers site is for breakin only. The original post said nothing about break in. It was a general statement about oil use.

Sporter28

Forgot about the tech bulletin from Comp Cams concerning this subject. Among other things, they recommend oils with zinc be used and actually recommend Rotella T oil (diesel oil) for break-in. Several professional engine builders also recommend the diesel oil for both break-in and daily use because it has sufficient levels of zinc. Another option is to use the oil of your choice and just add a quart of GM EOS (engine oil supplement) both at initial break-in and every oil change afterward.

http://www.compcams.com/information/...yID=1985582846

ws6transam

I wiped out lobes on my last two hydraulic flat tappet cams even after following all break-in procedures. I was kind of wondering bout the zinc level actually, before seeing this thread. Thanks for bringing it up.

Evoboy

Well,now that we know that Slick 50 did absolutely Little as
promised for extended engine wear,I say always Buyer Beware.
The japanese use full synthetic for their Evo's.I'm not sure if they
bench break-in their high-output 4 cylinders on other oil first.
A new engine has to seat the rings and sheer a little metal from
the close tolerances.