MYquadsFaster Posted January 30, 2006 Report Share Posted January 30, 2006 im running 190 195 in my cylinders is this too high for pump gas? should i switch to race fuel? its bored 80 over with with 21 cc domes Quote Link to comment Share on other sites More sharing options...
ngelati Posted January 30, 2006 Report Share Posted January 30, 2006 FYI Description *Compression **Octane Head w/16cc domes 210lbs 115 octane Head w/17cc domes 200lbs 112 Octane Head w/18cc domes 190lbs 110 octane Head w/19cc domes 180lbs 105 octane Head w/20cc domes 170lbs 98 octane Head w/21cc domes 160lbs 91 octane Head w/22cc domes 150lbs 91 octane Quote Link to comment Share on other sites More sharing options...
MYquadsFaster Posted January 30, 2006 Author Report Share Posted January 30, 2006 so do you think my compression tester is wrong or could there be something else making the compression so high? Quote Link to comment Share on other sites More sharing options...
MYquadsFaster Posted January 30, 2006 Author Report Share Posted January 30, 2006 i live near pontiac michigan i believe its 973 feet Quote Link to comment Share on other sites More sharing options...
FIRST BANSHEE Posted January 30, 2006 Report Share Posted January 30, 2006 (edited) i live near pontiac michigan i believe its 973 feet 466532[/snapback] I think your tester my be wrong or your dome size is wrong, at 190-195 psi you need race fuel.what type of pistons are you running? Edited January 30, 2006 by FIRST BANSHEE Quote Link to comment Share on other sites More sharing options...
hittintrees srh Posted January 30, 2006 Report Share Posted January 30, 2006 a good rule-of-thumb is anything over 160-165 psi, you should run atleast a 50/50 mix 195psi, i think i'd be running 100% race fuel-something like 110 octane. just my .02 Quote Link to comment Share on other sites More sharing options...
RNBRAD Posted January 31, 2006 Report Share Posted January 31, 2006 what is your altitude ?this has a huge effect on compression and wether or not you need race fuel.i've seen a shee run on pump gas with 220 pounds of compression at 3000 ft altitude and run just fine with no problems whatso ever .altitude also has a effect on hp. 466527[/snapback] So do you recommend this for these BHQ riders? I don't think I would post something that defies all octane vs compression rules. You have some misinformation somewhere, I guarantee it. Quote Link to comment Share on other sites More sharing options...
Old Two-Smoke Posted January 31, 2006 Report Share Posted January 31, 2006 what is your altitude ?this has a huge effect on compression and wether or not you need race fuel.i've seen a shee run on pump gas with 220 pounds of compression at 3000 ft altitude and run just fine with no problems whatso ever .altitude also has a effect on hp. 466527[/snapback] 220 lbs at 3000 ft on pump gas thats a stretch Quote Link to comment Share on other sites More sharing options...
chase@miamiatv.com Posted January 31, 2006 Report Share Posted January 31, 2006 i listend to him and now my banshees blown . just kiddin Quote Link to comment Share on other sites More sharing options...
Old Two-Smoke Posted January 31, 2006 Report Share Posted January 31, 2006 On second thought he just saved me a bunch of money flying I am gonna fill one tank with Av gas and the other with pump gas soon as I get above sea level I switch over to pump gas. l Quote Link to comment Share on other sites More sharing options...
BlazinOne Posted January 31, 2006 Report Share Posted January 31, 2006 FYI Description *Compression **Octane Head w/16cc domes 210lbs 115 octane Head w/17cc domes 200lbs 112 Octane Head w/18cc domes 190lbs 110 octane Head w/19cc domes 180lbs 105 octane Head w/20cc domes 170lbs 98 octane Head w/21cc domes 160lbs 91 octane Head w/22cc domes 150lbs 91 octane 466464[/snapback] i would only use this as a reference.It all depends how your engine is set up.I run 170 psi on 18 cc domes and 94 octane.The domes were recut which would allow up to 180psi still on pump gas.The squish is what dictates octane requirements.Every application is different. Quote Link to comment Share on other sites More sharing options...
badassbanshee479 Posted January 31, 2006 Report Share Posted January 31, 2006 Michigan is at sea level just to let ya know. Quote Link to comment Share on other sites More sharing options...
locogato11283 Posted January 31, 2006 Report Share Posted January 31, 2006 if ur 1000 feet above and have 195 pounds you need race fuel for sure. but i would check to see if your tester is fucked up. you shouldnt be at 195 with 21 cc domes.. Quote Link to comment Share on other sites More sharing options...
MYquadsFaster Posted January 31, 2006 Author Report Share Posted January 31, 2006 ok i found that my compression tester was bunk. but i still need help....my left cylinder runs strong and sounds great but once i start it up and it idles for a minute the right cylinder goes out untill i rev it up and than it will kick back in. and when i choke it they both run good i can take the right plug off and it will start and run on only the left cylinder but it will not run on just the right cylinder i found my compression is about 20 pounds off between cylinders 150 in the right 170 in the left, i recently blew the left piston and had to rebuild the top end and now my right cylinder is low on compression. when took the top end apart the left piston had a hole through the top and the right cylinder looked excellent no problems at all. and now with new pistons and a cylinder hone's the left runs great and the rights got 20 pounds less compression... Quote Link to comment Share on other sites More sharing options...
badassbanshee479 Posted January 31, 2006 Report Share Posted January 31, 2006 check and make sure your carbs are insinc with one another, also try switching the plug wires and see if the porblem switches sides, but it sounds like the carbs are out. Quote Link to comment Share on other sites More sharing options...
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