cool head size

[tennquadzilla]

alright i already have a cool head with the stock (62) dome in it . i've got the zilla down right now doing a few things to her before this season of flattrack . how much of a difference would it make and what are the negatives to putting the smaller domes either a 53 57 or 59 dome in it . as if its not enough a bear already to kick does the smaller domes make a big difference in compression .

[tennquadzilla]

come on guys i really need some help

[gh500]

from what I've seen the higher the compression the more torque it will make and at a lower rpm but hurts it up on top end you also need better fuel for the higher compression ratio's what it boils down to is where do you need the power

[burgiebird]

Im no expert but more compression means more octain and more fuel. The higher the compression the more port work you need to get done to keep the full range of power. I would not go smaller than a 59mm if you wanna keep it reliable. I have a 62mm on mine and its got a 90mm piston it it. It runs good in all ranges. You will have to tune and re-jet butI would try a 59mm and see how you like it.

[tennquadzilla]

thanks alot man i'm at an 89mm piston right now and i added a trinity stage 4 pipe and was just wanting to regain some of my bottom end and thought that would be one way to do it

[burgiebird]

That pipe is all good just try the 59mm and see how she runs. If all else fails sell the dome and port.

[gh500]

if your wanting bottom end put some compression in it that will wake it up also dome size needed depends on what porting you have

[tennquadzilla]

virtually stock porting just been cleaned and polished a little . i know everybody is gonna say dont waste your time doing anything until you port it but i'm already at 120 over and dont want to port it until i resleeve and get back closer to stock bore . then i'll let denny work his magic with it but for now just want to bump it up a little to make up for my pipe

[ERBE]

well any thing over stock you should run race fuel in the LT500, that said, a #57 dome will bump up compression, add power, but the cool domes are not cut correctly on the sqish angles there off I think about 1 deg (14 deg vs needing a 15 deg), you will need that done to get best performance, most cycle shops can do that for 30 - 50 bucks