Master of Faster Posted June 8, 2007 Report Posted June 8, 2007 Hey guys, I just put my new 4-mil together and I'm sitting at .035" squish right now. I need to stay on pump gas, is this gonna be too tight? I do have the head rechambered with a little steeper squish band to fit the piston better. I'm stuck as to what to do right now, on one hand I wanna be safe with a brand new motor but on the other hand I want it to run as strong as possible. I haven't gotten it back in the bike yet to see what the compression is but I'm working on it now. Quote
Snopczynski Posted June 8, 2007 Report Posted June 8, 2007 get a thicker head gasket. Ideal squish is .040"-.065" Quote
dajogejr Posted June 8, 2007 Report Posted June 8, 2007 Thicker base gaskets. Raise the port timings up a hair...and give you more squish. Don't be afraid to use a little RTV and double up a base gasket to get the squish you want... Mid .040s is ideal on a stock bore motor. Quote
badassbanshee479 Posted June 9, 2007 Report Posted June 9, 2007 defently raise it up! stock head, tight squish, low octane, no good. I have a couple gaskets under my cub cylinder, like dave said throw some rtv on um and run it! Quote
blowit Posted June 9, 2007 Report Posted June 9, 2007 defently raise it up! stock head, tight squish, low octane, no good. I have a couple gaskets under my cub cylinder, like dave said throw some rtv on um and run it! HUH?? are we equating squish clearance to compression? Actually, the tighter that number, the less the chance of detonation. Who ever set that head knew what they were doing. Run it. WE have built hundreds of those heads and 90% of them on pump fuel. Just make sure to check your compression with it installed. Brandon Quote
Snopczynski Posted June 9, 2007 Report Posted June 9, 2007 I wouldn't put dual base gaskets under it, he probably had it ported if he put a 4mill in it, it should already be at the height that the builder wants. Quote
Master of Faster Posted June 9, 2007 Author Report Posted June 9, 2007 Put the compression tester on it and got 155 psi so I just decided to go ahead and run it today, watched the plugs real close for awhile and no problems at all. Runs very well, but thanks for help guys. Quote
Snopczynski Posted June 9, 2007 Report Posted June 9, 2007 Do us a favor, after you break it in and run a tank or two through it check the compression again and see where it is at. Quote
Master of Faster Posted June 11, 2007 Author Report Posted June 11, 2007 Do us a favor, after you break it in and run a tank or two through it check the compression again and see where it is at. Got a little over a tank run through it hard, compression is about 158 psi now on both sides, just a tad higher than when I first put it together. Its running great and so signs of problems at all. Quote
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.