What would you do to get the compression down?

[turbowrenchhead]

I have a stock stroke and 66mm pro lite pistons with stock ported heads. Noss head w/ 22cc domes. I recently changed out the cylinders and pistons. The cylinders were decked .004 because of a nick in the head. I'm using a .015 base gasket and my squish is at .045 with that. I was told between .040 & .050 is optimal. I did a cc fluid check and I get 15cc's in the chamber with 22cc domes. By method of a online calculator(http://www.cbperformance.com/v/enginecalc.html)

I get a cranking compression of 160psi. That puts me at 14.5:1 compression. Way to high for pump gas. 23cc domes would lower my cranking and my uccr compression. The thicker the base gasket I use will increase my squish. Then I'm out of the optimal range. If I run the .031 base it will drop compression to 12.5:1 but increase my squish to.061. Last year I didn't know my uccr but my cranking compression was 150psi with 21cc domes, stock base gasket (.026) and undecked heads. The bike ran great last year and even ran a tank of 87 octane in it with no problems. The pistons didn't show any signs of detention either.

 

[Coupelx]

i would quit half assing shit and have some domes cut for it.

 

if it only took .004 to clean up a scratch i woulda filled it with jb weld and ran the fucker.

[turbowrenchhead]

Don't have time to cut domes for it. Big trip of the year is 7 days.

[Coupelx]

have you bothered to call anyone?

[turbowrenchhead]

I just found this out tonight. Whom might I call?

[BANSHEE HP]

.020 base gasket and run 93 octane

[oldskool]

more octane, go ride

[SAVAGE420]

Drill a small hole in tops of pistons . =)

[turbowrenchhead]

I'm lucky if they have 91 octane in the rural areas I go riding in. We go on 100 mile rides. Usually we head to a town 40~50 miles away, fill up and head back

[Coupelx]

I'd start with noss machine seeing as domes are what he does...

[turbowrenchhead]

I emailed him last night and left a message this morning. I will need them by Thursday next week or I'll have to go with bigger base gaskets.

[m671054]

Bigger base gasket = higher exh port duration.

[turbowrenchhead]

Bigger base gasket = higher exh port duration.

 Yes I know

[J-Madd]

You can usually get domes from Noss in a couple of days.

[WINDYCITYJOHN400]

Don't have time to cut domes for it. Big trip of the year is 7 days.

This is the price of earning late in the game.

Run a thicker base gasket for now. The squish will open up....but that's better than too tight or too much compression.

Maximizing power for a long trail ride doesn't seem to be a big priority. Not to mention the need to get jetting established for this new motor........