Imabadman

I polished out the combustion chambers on my SR Torquer heads and then measured the chamber volume. The combustion chambers were advertised at 67cc. Measuring the chambers after I polished them, I had removed around 3.5 cc's!!!!!! Could I have possibly removed that much material? I removed barely enough material to lose the rough casting surface(or so I thought) which was pretty smooth to begin with. Is it possible that the advertised chamber volume could be off? I went ahead and assembled the engine, adjusting the gasket thickness for proper quench/compression but damn!
What do you guys think?

I measured the chamber volume by placing a piece of plexiglass over the chamber and injecting some alcohol in with a big horse needle(accurate to the tenth of a cc).


[Modified by Imabadman, 5:18 AM 2/1/2002]

1979toy

I'm not surprised at all. Be happy that you didn't measure a set of GM heads. Often, the GM heads are 86cc's rather than 76.

Imabadman

Wow, that really puts things into perspective. How much is the usual variation between chambers? Can compression differences cause engine damage?

Smokehouse69

My Vortecs were 61.2 to 62.5 cc's before I polished and unshrouded the exhaust valves. Checked out to 65-66 afterwards. Removed more than I thought! But I will still end up about 10 to 1 according to the calculations, with a .042 squelch area.