[Euro1320Racer]

High zinc/phosphorous package oils are advantageous for flat tappet cam owners. If you aren't running a flat tappet cam it isn't going to do much for you. We break in our flat tappet cams with a can of GM E.O.S. and any dino oil we may have in our shop. E.O.S is basically the only zinc additive worth a damn to ADD to an oil especially for camshaft break in where the ZDDP package is essential for a flat tappet.

If you've followed some of the oil testing on bobstheoilguy.com from blackstone labs, you'll see that many of these companies fabricate their ZDDP numbers and the content is minimal.

For example:

**EDIT**

VALVOLINES NSL & VR1 RACING OILS(1200-1250PPM WHEN TESTED MFG CLAIMES 1300-1350 PPM)

SHELLS' ROTELLA ST 30WT (APPROX 1250-1300PPM)

NOTE:1200PPM-1400PPM ZDDP IS THE GENERAL REC ZDDP LVL FOR FLAT TAPPET CAMS WITH THE HOT CAMS WITH HI SPRING RATES BEING AT THE HIGHER 1350-1400PPM LVL.

NOTE:I DIDNT MENTION THE VALVOLINE RACING NSL/VR1 OILS BECAUSE THEY APPROX 1150-1250PPM ZDDP ON AVG WHEN TESTED WHICH IS MARGIANL IN SOME CASES. SO THEY ARE OK FOR STOCK TO VERY MILD FLAT TAPPET CAMS . BUT I DONT LIKE THE LOW/MARGIANL AVG 1200PPM ZDDP LVL THEY HAVE FOR HOT CAMS WITH HI SPRING RATES.

[lifted from SWHEATON at chevelles.com] **END EDIT**

So to better answer your question pertaining to what type of oil to use (high ZDDP, etc) and viscosity (weight), I think two questions pertain.

1.) What are you main/rod bearing clearances with what oiling system

2.) and are you running a flat tappet cam?

Cheers,
Alex