What I need to find out now is my compression ratio.
You might find some calculators on the internet that will get you close, but...you really need to know CC's of the head, head gasket thickness, bore, stroke, CC's of the piston and/or just total CC's at TDC for the cylinder. My wild guess is it is going to be high. Maybe too high. Compression test it, while there is some relation between that and CR, (a lot depends upon timing) you will know if you are close or just way up there.
How much smaller are the combustion chambers on the 2.3? If it signifigant. I would start that puppy with the timing retarded, run some high octane gas and be careful as you tune it. Without a knock sensor, by the time you hear detonation, it will be too late.
Good Luck,
Michael
The 2.3 chamber is significantly smaller, I also noticed that the 2.6 valves are shorter about the size of the keeper recess (about 1/8th of an inch). I was going to use the 2.6 valves on the 2.3, luckily I double checked the length otherwise the springs would of binded.
I think the shorter valves on the 2.6 makes up for the deeper chamber whereas the 2.3 has a shallower chamber needing a bit longer valve. Valve angles on both heads look to be the same tho.
I did initially start the motor retarded. It ran a little sluggish at first, it's at 6 degress advance right now on 91 octane pump gas. I'll play around with the timing some more after I find some race gas.
What do you think 100 or 110 octane? I was thinking of the 110 to be more on the safe side...
I haven't done a compression check yet, last time I did one was on the 2.6 head and i had 120psi across the board. I know it's kinda low, that's due to the cam profile I have in there. I did gain another 15psi when I installed the adjustable timing sprocket to 3 degrees advanced <img src="/forums/images/graemlins/kewl.gif" alt="" />.
I'll try to get a comp test done and maybe I can get a ballpark figure based on those numbers.
