This has probably been around before and beaten to death. I am getting ready to fill the crankcase for the first time on my 350 flat tappet cam rebuild. Sooooo many choices. Synthetic or refined????? Correct weight...........How much zinc etc. I would be interested in hearing your preferences and why? I used to think Havoline Gold 10W40 was the thing....well they don't make that sh?! T anymore. Decisions Decisions......"..

 

You'll get a different answer from everybody. I only use Castrol... why... because it's what I have always used.

 

I agree with NHolds on at least one thing, you will get a different answer from everyone. Personally, I have been using Pennzoil for the last 30 years and have never had a problem with any of my cars. Just regular and not synthetic. I have heard on various car shows that synthetic does not lubricate all of the seals as well as regular oil does.

However, I am also one of those strange people that change my oil and filter every 3000 miles and not 5-6000.

 

I always used Pennzoil also, since I first began changing my own oil back in the '60's. And I always used GM (EOS) engine oil supplement at each change! Late, when I worked for a Mopar dealership, I switched to Mopar (EOS) engine oil supplement....but I'm not sure either of these are still available. As a side note....I'm not even sure what modern oils are made of.....probably a blend of real vs. synthetic.....??? Back in the day, we always were taught that Pennsyvania crude oil had the best lubricating properties, hence Quaker State and Pennzoil, etc...but who knows what you are getting today!!!

The important part is the ZDDP content of the oil, which has virtually been eliminated from today's engine oils, as it is detrimental to both catalytic converters AND the environment! It is not necessary today due to improved metalurgy, and roller tappets/camshafts that eliminate the "scuffing" factor.

But LACK of zinc additives is detrimental to flat tappet camshafts....

So this leaves us where???

http://zddplus.com/

To further complicate the issue, most of todays camshafts are labeled flat tappet, when they are actually hydraulic lifter cams! A true flat tappet cam has adjustable rocker arms, and requires constant adjustment.....! But BOTH require an additive that is no longer included in modern engine oils, hence the need for a supplement!

The important part of breaking in a new "flat tappet" cam is to observe proper break-in procedure.....and....be sure to use the proper assembly lube on all parts when puting it together!!

 

I use Brad Penn Penn Grade 1 SAE 20 w 50 partial synthetic for muscle cars. The speed shop that built my motor uses it.

 

x2, or buy a good ZDDP suplement at least for break in purposes, also Valvoline racing oil has good zddp levels.

 

I use Valvoline VR1 for 3 reasons.

It received favorable remarks in an oil study found online.
Contains the needed amount of ZDDP.
Is readily available at my local Napa.

 

Mobil one 15w50 for 25+years.