Fuel

[Richard P.]

What fuel and/or additives should I use in an original 365 HP engine?

[Jim T.]

Re: Fuel

My original owner 68 327 L79 with original engine and about 95K runs just great on pump premium. Its timed 10 degrees BTDC with original operating vacuum advance.

[Richard D.]

Re: Fuel

I've run Sunoco 260 (94 octane) in my L79 (11:0 compression) and stock settings, and haven't heard any pinging yet.

I also run pure Techron (Chevron product) to keep things cleaned out and prevent carbon build up.

Rich

[Wayne K.]

Re: Fuel

Rick,

Some folks here might disagree but I believe one should use a lead additive if the heads have not had hardened seats installed. Without the hardened seats I think that you are running the risk of the valves hammering out the seats. This has been my experience.

[Tom Merkel]

Re: Fuel

Rick - In my '67 L-79 I run pump 93 octane, or if available, Sunoco 260/94 octane, and it doesn't ping.

Tom

[Jack H.]

Daimler-Benz

had a very nice white paper on the subject of lead back in the mid-70 era when the US was phasing out leaded gas. Essentially, their research concluded once an engine designed/built for leaded gas had seen 5000 miles of operation, it had received all the lead it'd ever need to thwart valve recission for the balance of its useful life.

That white paper was quick to differentiate between the value of lead for valve train performance vs. the octane boost effect though. They concluded there's no substitute for a high octane fuel's precision burn characteristics in a high compression engine environment and owners of older cars really DID need to maintain fuel quality, regardless of lead/no-lead....

[Richard P.]

Re: Fuel

Thanks, guys.

[Wayne W.]

Re: Fuel

I have a copy of studies back in about 75 done by the EPA and some major university labs. It basically concludes that valve recession is not a problem except on engines subject to continuous and extreem conditions. It also concludes that anti wear additives are essentially useless. If you use enough to reduce wear, engine deposits are excessive.