what size domes can i use?

[sheerider11]

what size domes can I use?

4 mill short rod, .020 over, race gas is not an option, 93 is the best i can get.

was thinking 20cc or should i go with 22?

thanks for the help.

[Finch]

whats your elevation that will depend on which ones and what compression you at now?

[sheerider11]

whats your elevation that will depend on which ones and what compression you at now?

I'm at sea level, and I just got my motor back from HJR with a port and a whole fresh top end, but haven't gotten it back together. That's why I want to know what domes I should run.

[Finch]

I'm at sea level, and I just got my motor back from HJR with a port and a whole fresh top end, but haven't gotten it back together. That's why I want to know what domes I should run.

 

id put it together and check comp. or hit up hjr and see what they suggest good idea to talk to the guy he did your motor work

[Finch]

and 22 is same as stock. so shouldnt change to much

[sheerider11]

and 22 is same as stock. so shouldnt change to much

okay, that's good to know, well I think i should be safe to go to 20 cc then.

Unless some one else has input.

or should I really get where my compression is at now?

[Finch]

thats up to you if ya dont wanna run race gas and put in 20s and are to high be a bummer but domes are easy to change i have 19s but im also at 5000 feet so im still only at 130s

[sheerider11]

thats up to you if ya dont wanna run race gas and put in 20s and are to high be a bummer but domes are easy to change i have 19s but im also at 5000 feet so im still only at 130s

yeah F that. I'll do it the right way and get back to you with the psi

[Finch]

yeah F that. I'll do it the right way and get back to you with the psi

 

ya someone might have better idea being at sea level like i said good idea to ask hjr since they did your motor work and ya if ya decide to change 10bolts isnt to hard to change head or domes

[sheerider11]

ya someone might have better idea being at sea level like i said good idea to ask hjr since they did your motor work and ya if ya decide to change 10bolts isnt to hard to change head or domes

 

 

thanks for the help mike

[Finch]

thanks for the help mike

 

welcome im still learning too but ive been reading non stop for weeks and just relaying some info i know it kinda sucks to search for shit on here but i more or less like to trial and error and learn for my self

[willardwright59]

okay, that's good to know, well I think i should be safe to go to 20 cc then.

Unless some one else has input.

or should I really get where my compression is at now?

one of our banshee is running 20cc domes with a trinity stage VI cool head and its not even on 93 pump i think its just regular unleded and we've never had any problems with it, just make sure your jetted right and keep a close eye on your temperature during break in.

[EvilBanshee]

A Buddy of mine has a ported 350 with 19cc domes, he runs 91 and adds octane booster. Has never had a problem. We both are at sea level. i wiouldnt think twice to run 20cc with 93 octane.

[dajogejr]

In order to give you an accurate answer, you need to get accurate information. Compression ratio needs to be used to calculate the need for higher octane, not cranking compression. If you base it off of cranking compression you are only guessing at best. Yes, it is more work...and yes, you will have to take measurements. But it's your money and your motor...is it worth your risky guess or is it worth taking a little more time and knowing you are starting off on the right foot?

 

 

You have a 4 mil motor that changes everything, so don't take advice based on a stock crank.

Also...don't use octane booster. It's garbage, especially in a high revving two stroke motor.

[lms1977]

what did the builder tell you to run?