The objective is to raise the CR's until E85 can be run efficiently. It has 20% less fuel energy and is 10% lower in price so to be as cost effective I would need to get 10% more power. Given the packaging of the engine the best bet looks to increase the stroke (more time under the expansion curve) and the compression (more pressure in the cylinder).

I have a set of 307's for one of my 250 gas projects, but that won't let me up the stroke.

I'm up on the piston compression heights. What I don't know and haven't been able to find is the nominal quench height (ie how far the piston is down the bore).

Dropping the 250 crank into the 194 would get me more cubes, but what I was really after is a significant boost in compression. The concern is the added stroke will raise the piston .15" up the bore, and I'm not sure if there is enough space for that. If not I might be able to turn down the top assuming there is enough ring land. Ditto with using 230 pistons, the added compression height is exactly equal to the increase of stroke 230 to 250. So if I used the 230 pisons and turn down the outer edges (make them clsoer to flattops) I should be able to pick up the CR.

Last edited by D13; 12/10/2009 5:07 PM.