Large valved 273

replicaracer43 said
plus harder to get compression in a small bore, that's the reason the factory had to use a dome piston.

dibbons said
The larger the cylinder volume, the easier it is to squeeze it down=high compression. When you start out with a smaller cylinder volume, it is more difficult to make it even smaller.
It's just math/physics.

But if you are talking ratio, how does the differences in volume make a difference? It's a ratio so the differences/changes would be a mute point? I understand it would affect compression PSI.
I also understand its math/physics.

66fs said
Look at a 340. 10.5 at the top of the bore. 273 has a dome to get the same Compression ratio. Really a mute point on the street, since you can't run 10.5 on pump gas. I shoot for 9.0. I'm not going to worry too much about compression as much as flow. Race engine is another story.

A 340 doesnt sit out of the bore as much? Sorry, brainfart here, but stroke is the same 273 vs 340? 6.123?

oldkimmer said
With the bigger open chamber of the 340/360 head u loose compression. Sour now 10.5 is down to 9ish to 1. So in effect u have to try to fill up the gaping hole u created. For that to happen u would need a Hemi type piston with a bump as big as ur fist and deep valve reliefs machined into them. Which may or may not be feasible. Kim

Yep I understand the compression change with heads(open vs closed chamber)
Thanks guys, trying to absorb.......beer is easier to absorb lol