Different domes, different compression?

[ltracer250r]

Oksy, so i got a pro design cool head on my shee, if i change the doems to a bigger say 22cc dome will my compression go up? OR what will i need for my compression to go up?
Thanks and Peace Out

[sparkzilla]

Smaller domes are for more compression.

[ltracer250r]

So if my compression sucks i need to findt he smallest dome i can? Or the smallest big bore dome.

[sparkzilla]

Actually if your compression sucks that bad you need rings.

[scream'ntwostroke]

The smaller you go on the domes(like an 18cc) you need to run higher octane fuel. But say you run 21cc domes you can just run 94. But like 18cc domes will rise compressssion you just need to get race gas for like 6 bucks a gallon. I would just run 21cc domes and run regualr fuel. But if you feel low on compression check the cylinders, you might need a new top-end.

[ltracer250r]

Yah i am gonna rebuild it soon, to get ready for the lakes, i was just stumped on the whole different dome sizes issues. My compression isnt that bad, easily beat 4 pokes in the drags, but i gotta freshen up for this winter when we have the tenth mile drag and when you go up against zillas you better have something ready.

[J.J.]

I see in your sig that you are running a big bore, don't know what your present bore size is but, above 65mm you have squish clearance issues with big bore cylinders and stock bore domes. This will become more of an issue as you increase the compression when going to a smaller volume dome.
In this case you'll need custom cut domes or big bore domes.

Don't know if this applies to you, but you might wanna keep that mind when you're making your purchase...

[ltracer250r]

Thanks JJ yah i do have a big bore. Im gonna have to see what size domes he has in there right now and go from there.