Recently did a rebuild with a 4mil, woods port, 20cc custom domes, single carb, etc....I ran 100\110 oct gas since the rebuild since when I first tested it the comp tester showed 200+ psi! Now its about 180 in each cyl, however I want to run 93 octane not race gas!
Should I go up to 21cc domes to lower the compression closer to 160 or 150 (jetting is close to prefect maybe a little rich). I dont want to go higher to 22cc as thats pretty much stock. Not sure how at sea level these 20cc domes have so much compression. I know it also has to do with the porting, but its a fast woods ported 4mil. I tested it with 2 different testers and they are both within 3-4 lbs of each other!
Could it be a problem with the special cut domes for the 4mil and coolhead? It runs great!!