dome's

[Zbadboy]

Okay i could use some help getting learned up on domes for cool heads, please. I recently purchased a 4mil crank and currently an not sure what way i will go on the top end with tax returns in the near future serval or cheetah might be a option instead of port job on stock cylinders which was the beggining plan. I also purchased a cool head and will need to get domes. This is the part i need help with from what i am getting there is small bore and big bore domes but is anything special needed for use with a 4mil crank? and if i go with a serval or cheetah can the cool head be used there or will i just need to sale it? I see where sponers offer to mil stock heads to work with these and this is why i am curouis if anything special needs to be done to these domes.

[mpd579]

I just went with a 4 mil on I had HJR do a set of custom cut domes 85 bucks. Since you already have the cool head I won't worry about getting the stock head shaved....won't save you much $$$ and the cool head with custom domes is a better setup.

 

I don't know about the big money top end stuff if it will work or not. I'm running the stock cylinders that have been ported. One of the other guys will chime in with the answer though

[yz4jdm]

Okay i could use some help getting learned up on domes for cool heads, please. I recently purchased a 4mil crank and currently an not sure what way i will go on the top end with tax returns in the near future serval or cheetah might be a option instead of port job on stock cylinders which was the beggining plan. I also purchased a cool head and will need to get domes. This is the part i need help with from what i am getting there is small bore and big bore domes but is anything special needed for use with a 4mil crank? and if i go with a serval or cheetah can the cool head be used there or will i just need to sale it? I see where sponers offer to mil stock heads to work with these and this is why i am curouis if anything special needs to be done to these domes.

 

 

The domes sizes in the cool head provide different CC's for compression ratio changes. From what I remember when I was running the CUB I could not use the cool head on the cylinder.

[BigRed350x]

Okay i could use some help getting learned up on domes for cool heads, please. I recently purchased a 4mil crank and currently an not sure what way i will go on the top end with tax returns in the near future serval or cheetah might be a option instead of port job on stock cylinders which was the beggining plan. I also purchased a cool head and will need to get domes. This is the part i need help with from what i am getting there is small bore and big bore domes but is anything special needed for use with a 4mil crank? and if i go with a serval or cheetah can the cool head be used there or will i just need to sale it? I see where sponers offer to mil stock heads to work with these and this is why i am curouis if anything special needs to be done to these domes.

 

 

If you are running stock cylinders with no spacer plate, you will need cut domes for the 4mil crank. (Best way to go IMO) If you run a spacer plate you can run off-the-shelf domes. Cub and Serval cylinders CAN use the cool head, but if you step up to a cheetah other other cylinder you won't be able to use the cool head you already have. The smaller the cc number on the dome, the higher compression you will have. Big-bore domes are used on 68mm and larger bore cylinders (cheetah cub, serval, bored out stock cylinders) If you are running stock cylinders up to .100 over you will be fine with the std small-bore domes.

 

Give kevin @ HJR a call, he can hook you up with custom cut domes for your 4mil if you go that route.

 

- Jared

[Shawn R]

It all comes down to what compression you want to run. The lower the CC number the higher compression your motor will be. There is a chart on NOSSmachine.com that breaks down the dome sizes and compression ratios.

[Zbadboy]

awesome info guys thank you. also gives me more questions lol. So with the 4mil crank if I use the spacer plate I can use off the self domes but somewhere I read the spacer plate isnt the best way to go? help me here because I woild loke to do it right. if I port the cylinder to go with the crank my guess is they would need to know if I'm useing a spacer or custom domes?

 

I'm in Utah and ride mostly in little saraha so 5-6grand elevation for pump gas I am being told 18cc domes is what I want but to aviod the spacer and do it right I need have them custom cut?

 

are the costum cut usable on a cub/serval? or just standard domes?

[akelly000]

Just my .02. I purchased my 05' 4mil and it already had the (spacer plate) and I have no complaints with it. Plus I can use any size domes right off the shelf and inexpensively swap them out as needed.