L79vette66

Does anyone have a original 350hp 327, with the CORRECT dome pistons NOT the flat topps, running on 93 oct. gas? How does it run? I'm going to blueprint a 327 to 350hp. I was told by the machine shop that the dome piston would give 11:1 compression with 64cc heads. Also, I would have to mix the 93oct. gas with racing gas. My heads are 462 humps reworked with harden seats (202 valves). NEED SO INFO.
THANKS,
mike

epylant

Never had a problem with running straight 93 pump gas on my L79, and it still has the original domed pistons in it.

vref

Me too but it does run better on Avgas 100 octane from the local airport.

Vetterodder

The factory figures were rounded up and a little exagerated for advertising purposes. Probably closer to 10.5 actual. The TRW replacements (same .125 dome and now marketed under Speed-Pro) were listed at 10.35 cr with a .039 gasket and 64cc chambers. I have those in my `65 and have no problem with 91 octane. If you would feel better using flat tops, I don't think the power difference would be major.

Hitch

Just in case anyone needs them I don't have the original correct domed pistons but I do have a set of STD bore TRW pistons that I pulled out of mine last winter.. The number stamped into the top is L2166N. Dave...

Ironcross

93-94 works fine with that set up. But as above, Avgas is better but not necessary until the high 11`s or 12.5-1.

Allcoupedup

I'm OK with the stock domed pistons, 93 octane, and 10 degrees initial timing, BUT in order for you to be confident you too will be OK you need to take two measurements.

1) Piston/Deck clearance
2) Combustion chamber volume.

With these two measurements (and the data from the domed pistons) you should be able to calculate a static compression ratio.

If your heads have been milled (you mentioned they were redone), your combustion chamber volume decreased which increases compression ratio.

Brian