compression/domes/head gasket

[rossthaboss11]

ok i just bored out my 61x topend to 2mm over so 83mm.ive got 28cc domes. the compression went from about 175-180 to 200-205psi. i am running a mix with race gas right now but i cant afford to be buying that all the time. what should i do to get my compression down just enough for 93 octane? thicker head gasket? new domes? any thing so i dont get detonation. un advance my timing? its not totally broken in yet the oil mixture is still 32:1 so once it brakes in and everything the compression might drop a little.

 

[SUPERTUNE]

Most likely a Westcoast head that uses the stock headgasket?
We can machine your domes or supply a ADA complete kit with some custom cut domes.
Call shop and speak to Radney for any pricing.

 

[rossthaboss11]

ive already got a westcoast head and the half girdle kit so im all set there, just wondering was some easier less expensive fixes were

 

[rossthaboss11]

anyone?

 

[LIVE2RIDE Powersports]

Shiit i have a wectcoast head with 2 sets of domes im selling. Mine pushing 165-170 with a brand new top end posting work. thats with 26cc race domes. I want around 190psi.

 

[rossthaboss11]

haha, the extra compreission definitly gives it alot of power. i just need a little bit less so i can run pump. 26cc domes and your only getting 165 psi that seems low to me

 

[LIVE2RIDE Powersports]

haha, the extra compreission definitly gives it alot of power. i just need a little bit less so i can run pump. 26cc domes and your only getting 165 psi that seems low to me

Ya it seems extremly low to me as well. I had some other domes in that didn't have markings and gave 145 in both. So i opened the new pack of 26cc domes and got 165 in both. Brand new topend, professionally ported and everything. The only thing i can think is that im using a new wsm gasket that may be alittle thick.

 

[rossthaboss11]

hmm well if thats the case for the gasket then that answers my question. i have the a wsm gasket and i thought it might be to thin and i could find a thicker one to lower the compression.

 

[rossthaboss11]

but with a brand new top end and everything with 26cc domes your compression should be very high. not sure why its not

 

[LIVE2RIDE Powersports]

but with a brand new top end and everything with 26cc domes your compression should be very high. not sure why its not

ya me either. i hope she runs strong.

 

[SUPERTUNE]

Most likely a Westcoast head that uses the stock headgasket?
We can machine your domes or supply a ADA complete kit with some custom cut domes.
Call shop and speak to Radney for any pricing.

I've already got a Westcoast head and the half girdle kit so I'm all set there, just wondering was some easier less expensive fixes were.

This would be a a cheaper way...

 

[JetManiac]

What SUPERTUNE is saying is:

We can machine your domes


He is saying that he can cut your domes to lower your compression. What he is not saying is that he can do it in such a way that you won't lose too much power, maintain proper squish clearance, etc, etc.

Just changing gasket thicknesses can lead to unexpected consequences and doesn't necessarily cost much less.

Think about it.

 

[kevbo]

A Westcoast head with 83MM bore? The domes are only 88MM, better make sure the head and gasket are lined up perfectly.

 

[rossthaboss11]

i changed the domes out so it would work for the 701.