View Full Version : Engine: Alternative oil?

K Russell
06-24-2014, 03:48 PM
Since zinc has been removed from most motor oils, and from what I understand, needed in these old engines, what about using something like Kendall (or any brand) diesel oil? It has high zinc content and would eliminate having to also buy the zinc additives.

Skip Lackie
06-24-2014, 04:21 PM
With all due respect, this subject has been beaten to death on this forum. Suggest you try entering "zinc additive" or some other key words in the search function. At the risk of over-simplifying the matter, there are a number of motor oils on the market that are specifically formulated to properly lubricate older flat-tappet engines. At one time, diesel oils were the solution, but their zinc content has been dramatically reduced in recent years.

06-24-2014, 04:24 PM
There are a number of oils that have sufficient ZDDP...Brad Penn, Joe Gibbs oil, Hemmings Motor News sells their own line. Just do a little research and you'll find it available.

Even the diesel oils have had their ZDDP levels reduced as well.

Realistically...unless you have a high performance, high pressure valve springs, you have little chance of problems with any good modern motor oil. If something goes wrong, it was ready to go wrong anyway. The oil will have made no difference.

Mike Van Veghten
06-24-2014, 04:35 PM
As Skip notes..............

My "daily driver", 259 (Stude !) powered Lark runs on Castrol 20-50 GTX oil. It has since I bought it over 12 years ago...and with NO...oil related problems.
AND....I removed the partial filtering filter about 10 years ago.

I'd say...that Castrol GTX oil works just fine with flat tappet cams/lifters.