oil

[sundown]

hi what engine oil and sae for a 1979 chevy 350 the engine is in a kit car

[powerstroke]

?? state of tune, FI or carb flat tappets or roller cam new or done a few miles ???
I think you would be safe with a basic 10/40 to get it running , then as above to find the best match,
back in the day valvoline racing 20/50 was very popular but there have been a move towards thinner synthetic
oils in the last few years .....

Edited by powerstroke on Saturday 24th December 21:40

[sundown]

flat top cam on carb alloy heads has a oil cooler as well

[transamaro]

I spoke with Joe Gibbs racing about oil for a '79 350 flat tappet. The oem spec is 5w30 so they recommend their HR series (which comes in varieties from 5w30 to 15e50)as it contains the right amount of zddp to protect a flat tappet. You can use synth or conventional, synth offers higher protection levels and stays more stable during heat cycling. Weight will depend on engine clearances and temps uses; tighter clearance = thinner oil, colder starter temps = thinner winter weight. 10-30 or 10-40 is usually a solid choice. 15 50 / 20 /50 is a heavy oil and is only needed if you're running high rpms all the time (racing).

[ringram]

About the best syn on the market is Mobil 1 10w/60 designed for the M5 V10 so lots of high pressure bearing surfaces.
It also states its for older vehicles aka tappets.

ZDDP from memory is 1200ppm, which is way better than the 800ppm of the normal syn stuff.

From Mobil uk web..

"Extra seal conditioners to help prevent oil leaks
Helps to reduce sludge build up to keep engines clean and prevent wear
Outstanding/Excellent oil film thickness for extra protection in older engines
Higher viscosity to help reduce oil burn off in older engines
More anti-wear additives to help protect worn engines
High performance basestocks for excellent all-round wear protection"