flat tappet cam engine oil

[John D.]

What engine oil would you recommend for a newly rebuild engine with a solid lifter cam. I understand that a lot of engine failures are happending in the first few minutes because the oil used did not contain the zinc additive.
Doing some fast reserach I found Shell Rotella has a fair amount of zinc and is basically a diesel oil but also used for gas engines. It's a 15-40w oil.
Quaker State 20-50 Racing oil has 1/3 more zinc than the Shell but it's pretty thick and would possibly raise the oil pressure around 10 lbs. Pennzoil 20-50 racing oil also contains the zinc and other additives. Can someone help me in selecting an engine oil for my '63 with solids that contains zinc and is of thinner consistency. I understand that an Oil treatment could be added to your favorite oil to compensate for the lubrication problem and save the new cam. I haven't been considering synthetic oil. thanks, John

[William C.]

Re: flat tappet cam engine oil

I'm using the Rotella in the new engine for my '65, with liberal break-in cam lube on the cam.

[Alan Drake]

Re: flat tappet cam engine oil

Also try Valvoline 10-30 the VR1 (pn 205)rated at SH/CD or pn VV850 Racing Oil that has more additives in it. Valvoline tech # 800-TEAM-VAL

[Duke W.]

Re: flat tappet cam engine oil

I recommend API CI-4 or CI-4 Plus (othewise know as "heavy duty diesel engine oil") in all vintage engines. Do not use the current spark igniton spec, SM. Modern engines have different lubrication requirements than vintage engine. Since they don't have as many sliding surfaces, SM oil has less ZDDP. The previous SL spec is okay, but not as good as CI-4. Brand is not important - just make sure the API service category is as stated above.

If it's an OE mechanical lifter cam with OE valvesprings, "break-in" is really not critical. GM never did it, but it's a good practice and doesn't take much effort.

Add a 16-oz. bottle of GM EOS to the CI-4 oil. EOS has a big dose of zinc diethyldithophosphate, ZDDP.

If you used assembly lubes - change the filter after cam break in because the solids in assembly lube can clog the filter, but DO NOT change the oil. The high dose of ZDDP should remain. Change the filter again at about 500 miles to purge break-in particles, but leave the oil in. Change both the oil and filter at 1000-1500, and continue to use CI-4 oil, but don't add EOS.

The commonly available SAE 15W-40 CI-4 oil is okay for cold starts down to about 10F, which should cover everyone who doesn't drive their Corvette in the coldest winter months.

Most CI-4 manufacturers also offer CI-4 oil in 10W-30, but it is tough to find. Most diesel engine operators use straight 30 or 40 or 15W-40.

Duke

[John D.]

Re: flat tappet cam engine oil

Duke, Thanks very much for your educated response. I will follow it to a T. I appreciate it and also appreciate the other responses. Several fellows emailed me and one even called. Luckily I found out before starting the engine. I understand that you and Clem as several others discussed this same subject this past year. I went into the archives but missed it. Thanks again, John

[Robert M.]

Re: flat tappet cam engine oil

John et al, I do not mean to hijack the thread but it brings to mind a question for Duke or whomever wishes to post. If a vintage engine has been rebuilt with a roller cam kit,are the oil requirements and breakin any different? Thanks.

[Duke W.]

Re: flat tappet cam engine oil

I don't think roller cams usually need the "breakin" recommended for flat tappet types, as long as valvespring pressure is reasonalbe.

EPA is pushing for longer emission warranties and the OEMs are concerned because there is a body of evidence that indicates the byproducts of phosphorous containing compounds (like ZDDP) can degrade catalysts, so the OEMs, working with API, agreed to a phosphorous limit in SM oil.

Nearly all modern engines have roller followers (even DOHC type), so they theoretically don't need as much ZDDP. But both vintage engines and modern engines share the same boundary lubrication conditions at ring reversal, and this is an area where ZDDP can help. So will modern engines see more rapid cylinder wall wear at the top of the bore? It will take years for the answer to this question to become apparent.

Current diesel engine oil additive formulations are superior for all engines. I am so concerned with the anti-wear quality of SM oil that I refuse to use it in my older cars that have catalysts. I have switched them to CI-4. They see low annual mileage accumulation and have low oil consumption, and I would rather replace a catalyst downstream than have to rebuild the valvtrain if not the entire engine.

Duke

[Jim T.]

Re: flat tappet cam engine oil

John you may find Shell Rotella 10-30 at your local WAL-MART, within the last year I have found it there.

[John D.]

Re: flat tappet cam engine oil

Thanks Jim, I had planned on going to Walmart today. Didn't know they had the 10-30W. Hopefully it's the C1-4 like Duke and numerous others have told me. Understand the 15-40 will do the job but wouldn't mind the thinner oil for break in. Also buying the GM EOS. Duke and others said the EOS has a big dose of Zinc diethy......., ZDDP. I went on line checking to see if there was a 10-30 but somehow missed it. You can't believe how many of my friends wrote and called about the above. It's sure nice being an NCRS member and dealing with such helpful and caring individuals. John D.