Dome Sizes.

[98'banshee]

Ok, sometime or another I WILL get around to porting my engine but at the same time I want to change the domes. I am at near sea level and want right around 140lbs of compression so I can still run 92 octane. So what cc size domes am I gonna need? I have a cool head on it and it only has 120lbs per side.

Edited July 17, 2007 by 98'banshee

[Snopczynski]

Ok, sometime or another I WILL get around to porting my engine but at the same time I want to change the domes. I am at near sea level and want right around 140lbs of compression so I can still run 92 octane. So what cc size domes am I gonna need? I have a cool head on it and it only has 120lbs per side.

 

I just switched out my 20cc domes at sea level and it was 155 psi in my bike. I ran 92 octane in it. 21cc domes will be around 140 psi.

[bentvalve]

hey and if you need them, i have brand new 21mm domes from dl noss. don

[dlnoss]

What size domes do you have to get 120 psi at sea level. 21cc should give you 140 to 145 with a top end that is in fair condition.

 

-David

[dawarriorman]

What size domes do you have to get 120 psi at sea level. 21cc should give you 140 to 145 with a top end that is in fair condition.

 

-David

21cc for me at 500 ft. Im running 152 lbs of compression. I would rebuild when I got that low, maybe thats just me though.

 

I guess by fair you mean getting close to time for a rebuild?

 

 

To the original poster, if you already have a cool head, and you have anything other than stock size (23 cc) domes, you might as well at least re-ring the pistons while you have the head off. Its only another 8 nuts to take off then reinstall.

Edited July 18, 2007 by dawarriorman

[Snopczynski]

I got a set of 20cc domes I can sell. They had about 12 hours on them.