Re: L78 Dyno
 

I don't have any spark knock problems with either of 2 L78s running premium. 36 Degree total advance.

Re: L78 Dyno
 

I would never deface a set of 840 or 291 heads by installing exhaust seats unless they were sunk, and only then I would install custom made small ID seats machined to size along with a one piece solid bronze guide honed to size with a very precise valve job, which would run easily on unleaded gas.

Re: L78 Dyno
 

FWIW,My engine builder did note that a lot of L78/L72 engines that get rebuilt don't actually get to 11:1 when completed, for whatever reasons (head gaskets etc.) I know that my L78 will ping/detonate with straight pump gas (stock everything basically, timing all in at 3k) It seems to run best on a mix of Cam2/Avgas and 93 pump gas

Re: L78 Dyno
 

Love the smell of cam2!

Re: L78 Dyno
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: JRSully</div><div class="ubbcode-body">FWIW,My engine builder did note that a lot of L78/L72 engines that get rebuilt don't actually get to 11:1 when completed, for whatever reasons (head gaskets etc.) I know that my L78 will ping/detonate with straight pump gas (stock everything basically, timing all in at 3k) It seems to run best on a mix of Cam2/Avgas and 93 pump gas </div></div>

Sounds like a good combo to me Sully.
That is a really good running car you have and you show it NOT much mercy.
Love it!

Re: L78 Dyno
 

You are correct Sammysan, It's gets wrung out regularly, but the relatively skinny 225 14s keep it from breaking anything for the most part

Re: L78 Dyno
 

that is the way to do that Jim. smaller, skinny tires = smaller, little breakage.