99michael Posted February 16, 2014 Report Share Posted February 16, 2014 Well,, bought this 99 last summer. Had a trinity motor in it. Was told it ran on 110. So I've been buying vp110 to run it for the time bein. When I first got it home, did a leak down and there was a leak on the right side intake. Fixed that an rode the rest of last season. Now I want to quit paying out the ass for race gas. So I picked up a snap on compression tester, and modquad head with 21cc prodesigne domes from Wes. Checked compression with the trinity head with 17cc domes and read 210-215 on the left and 205-210 on the right. Now with the 21cc I'm still reading 170 on the left and 160 on the right. Shouldn't there be a bigger difference switching from 17 to 21cc domes? Now I haven't been able to check the squish yet(waiting on caliper) but do you think that it may have too thin of base gaskets? What thickness should I buy when I do the topend? Quote Link to comment Share on other sites More sharing options...
#1JUANstunna Posted February 16, 2014 Report Share Posted February 16, 2014 http://www.nossmachine.com/banshee_heads.htm Scroll down and find the chart of domes and compression. Maybe this will help you. Quote Link to comment Share on other sites More sharing options...
sheerider11 Posted February 16, 2014 Report Share Posted February 16, 2014 Just sell me the bike. Its fucked. Quote Link to comment Share on other sites More sharing options...
WINDYCITYJOHN400 Posted February 16, 2014 Report Share Posted February 16, 2014 Trinity build 215 PSI ……maybe you should just switch to diesel. LMAO 2 Quote Link to comment Share on other sites More sharing options...
99michael Posted February 16, 2014 Author Report Share Posted February 16, 2014 Yea no shit.lol. No signs of detonation though. Well, that chart shows about 33 psi difference, so that's about right there. Haveta get my caliper in so I can check squish. But I'll bet its too tight. Don't know of any other reason it could still be that high. With it ported too. Quote Link to comment Share on other sites More sharing options...
Deadbeat Posted February 16, 2014 Report Share Posted February 16, 2014 must have a pretty stout midrange with that kind of comp and the pt mids, nice looking bike Quote Link to comment Share on other sites More sharing options...
trickedcarbine Posted February 17, 2014 Report Share Posted February 17, 2014 On stock cyl bikes you should see about 8-10 psi per 1cc of dome size. If those cylinders are ported and still cranking that high it definitely still needs higher octane. Quote Link to comment Share on other sites More sharing options...
99michael Posted February 22, 2014 Author Report Share Posted February 22, 2014 Well I finally got my caliper in. And the tightest spot for squish is .050, and the base gasket is .018 where its smashed and .021 where it's not. So I'm assuming its a .020 gasket.. So why do you guys think there's still that much comp? According to that chart I should be 148 ish with stock porting... Ends up I'm just gonna buy another set of mx ported cylinders already setup for pump, so I don't have to deal with the trinity crap anymore..lol.. Quote Link to comment Share on other sites More sharing options...
99michael Posted February 25, 2014 Author Report Share Posted February 25, 2014 ?? Quote Link to comment Share on other sites More sharing options...
KlotzBanshee Posted February 25, 2014 Report Share Posted February 25, 2014 You want to swap cylinders to avoid buying race fuel? ...am I confused here? at 160-170 you should be able to get away with a 50/50 mix pump/race gas. Quote Link to comment Share on other sites More sharing options...
99michael Posted February 25, 2014 Author Report Share Posted February 25, 2014 K,, But,,lol Off the shelf pro design 21cc domes. Stock stroke 513 series piston .020 base gasket .050 squish.. Mx porting.. It just doesnt make since to me how this can be 160-170 lbs with all that,, I haven't bought a degree wheel yet, but it's on my list. Quote Link to comment Share on other sites More sharing options...
99michael Posted February 25, 2014 Author Report Share Posted February 25, 2014 You want to swap cylinders to avoid buying race fuel? ...am I confused here? at 160-170 you should be able to get away with a 50/50 mix pump/race gas. I bought a better set that doesn't consist of trinity. But will prob end up using these on a buddies bike. Lookin to avoid any race gas or aviation,, Quote Link to comment Share on other sites More sharing options...
99michael Posted February 25, 2014 Author Report Share Posted February 25, 2014 Now with the 21cc I'm still reading 170 on the left and 160 on the right. Quote Link to comment Share on other sites More sharing options...
99michael Posted February 25, 2014 Author Report Share Posted February 25, 2014 (edited) Yea,,,lol,, or at least they look the same,,lol gonna have them checked out an see if He can get by with a hone an rings,, if not then bored. Then when we get it back together we can measure it out and have some domes made up.. Seems to be the best rout I think. Edited February 25, 2014 by 99michael Quote Link to comment Share on other sites More sharing options...
Empire Industries Posted February 25, 2014 Report Share Posted February 25, 2014 I have base gaskets made in a .028 thick material. Run those with a set of 22cc domes and you can run on straight pump gas (91). Another contributing factor to what fuel you should be running is timing advance. More timing advance = more chance of detonation. Quote Link to comment Share on other sites More sharing options...
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