jjfizzle51 Posted April 19, 2005 Report Share Posted April 19, 2005 hey i am going to get a coolhead and was woundering if i would have to run race gas with 21cc domes i have toomey t-5 pipes toomey 2:1 filters and jetts and i am going to get +3 advanced timing my elevation is about 5,000 feet here in SLC thanks Quote Link to comment Share on other sites More sharing options...
decon Posted April 19, 2005 Report Share Posted April 19, 2005 from my knowledge, with 21 and 22cc domes u can run pump gas. im not sure about 20cc domes. to be sure as dlnoss about it. Quote Link to comment Share on other sites More sharing options...
dlnoss Posted April 19, 2005 Report Share Posted April 19, 2005 At your elevation, 19cc domes (probably 18cc) would be fine with premium pump gas. If you take a riding trip to lower elevations, you would need to increase the octane. Quote Link to comment Share on other sites More sharing options...
jjfizzle51 Posted April 19, 2005 Author Report Share Posted April 19, 2005 so you say probley 18 why probley should i ask the local shop Quote Link to comment Share on other sites More sharing options...
Oilsmoke Posted April 19, 2005 Report Share Posted April 19, 2005 I would get 20cc domes and you be ok with 91 octane At are alt. I am runing 19cc on my Stroker and I am at 185 psi but i mix 50/50 race fuel mix for 103 and never had a problem. I live north of SLC I am at 4300 feet. at 21cc you be more than safe. Quote Link to comment Share on other sites More sharing options...
dlnoss Posted April 20, 2005 Report Share Posted April 20, 2005 so you say probley 18 why probley should i ask the local shop 18cc might be pushing it some at that elevation with pump gas. Quote Link to comment Share on other sites More sharing options...
jjfizzle51 Posted April 20, 2005 Author Report Share Posted April 20, 2005 ok thanks guys hey and oil smoke do you go to little sahara big sand mountain once i get my bike running well have to drag up the raceway Quote Link to comment Share on other sites More sharing options...
Oilsmoke Posted April 20, 2005 Report Share Posted April 20, 2005 ok thanks guys hey and oil smoke do you go to little sahara big sand mountain once i get my bike running well have to drag up the raceway 357608[/snapback] Well I think my son's and I Are planning on May 6 & 7 for a Dune trip there. Quote Link to comment Share on other sites More sharing options...
jjfizzle51 Posted April 20, 2005 Author Report Share Posted April 20, 2005 oh thats cool if youve never been there before you'll love it if you have youll still love it win win Quote Link to comment Share on other sites More sharing options...
05bansh Posted April 20, 2005 Report Share Posted April 20, 2005 (edited) I am running 19's here in slc (I only ride the dunes) I run a 50/50 mix of race gas. I think with 20's you would be safe to run premium pump gas. But why run the 20's when you can run the 19's? Run the race gas, get more compression, its the shiznitt!! Oilsmoke, and JJfizzle, lets plan a bansheehq dune trip to sand mountain I'll drag with guys!! Edited April 20, 2005 by 05bansh Quote Link to comment Share on other sites More sharing options...
jjfizzle51 Posted April 20, 2005 Author Report Share Posted April 20, 2005 ok you got to wait untill i get my cool head and advanced timing in july before i race you guys youll smoke me right now Quote Link to comment Share on other sites More sharing options...
rzcolobanshee Posted April 20, 2005 Report Share Posted April 20, 2005 (edited) You can go much smaller at that elevation, as long as your bore isn't over .030 you can down to 15cc domes, I had em in my banshee for 2 years with no problems and I'm at 5000ft That's on 91 octane btw Edited April 20, 2005 by rzcolobanshee Quote Link to comment Share on other sites More sharing options...
05bansh Posted April 21, 2005 Report Share Posted April 21, 2005 ok you got to wait untill i get my cool head and advanced timing in july before i race you guys youll smoke me right now 357984[/snapback] Sweet! Let me know, once the weather gets decent again I will be riding almost every weekend at Sand Mountain. You can go much smaller at that elevation, as long as your bore isn't over .030 you can down to 15cc domes, I had em in my banshee for 2 years with no problems and I'm at 5000ft That's on 91 octane btw 358008[/snapback] 15cc I would think thats quite a bit of compression if your not ported and have your crank welded. When I bought my Noss head, I talked to Dave, he recommended not going past the 19's here in slcc with factory crank & no port. Quote Link to comment Share on other sites More sharing options...
ScrewMachine Posted April 21, 2005 Report Share Posted April 21, 2005 15cc I would think thats quite a bit of compression if your not ported and have your crank welded. When I bought my Noss head, I talked to Dave, he recommended not going past the 19's here in slcc with factory crank & no port. 358212[/snapback] Yeah, we started doing that a long time ago just trying to make as much power as we could at these high elevations. Compression is the key when the air is this thin. IMHO My old shee, mildly ported, 28mm carbs, FMF GoldSeries pipes (obviously this was a LONG time ago ) and 14cc domes would only make about 195psi at Walden. Every setup is different. Really the only way to know fosho is to do a compression test. In other words, please don't do as I did and risk damage to your bike. Do you know what psi your shee is at now? You don't need race gas unless your pushing 160psi and I doubt you are with 19cc at 5000ft. But again, every setup is different. You prolly don't want my opinion , but I'm just trying to help out and maybe save you a few bucks. Prices of fuel are f***ing crazy! Quote Link to comment Share on other sites More sharing options...
rzcolobanshee Posted April 21, 2005 Report Share Posted April 21, 2005 I was only at 155 with 15's no porting, factory crank....bore size is the most important thing to watch, at .030 i was fine but a friend at .060 was detonating like crazy 15cc I would think thats quite a bit of compression if your not ported and have your crank welded. When I bought my Noss head, I talked to Dave, he recommended not going past the 19's here in slcc with factory crank & no port. 358212[/snapback] Quote Link to comment Share on other sites More sharing options...
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