compression after rebuild,

[wimpywade94]

Hey all, ive searched and didnt turn nothing up,

Will boring my bike over .030 lower my compression? I have a coolhead, dont have the domes yet, i plan on running 20's, I know there are a TON of variables to the question, so my main question is will the oversize piston lower my compression alot?

wade

[RATBIKE0130]

It actually increases your compression by a slight amount when you bore your cylinders out and don't change anything else.

[Washburn]

Hey all, ive searched and didnt turn nothing up,

Will boring my bike over .030 lower my compression? I have a coolhead, dont have the domes yet, i plan on running 20's, I know there are a TON of variables to the question, so my main question is will the oversize piston lower my compression alot?

wade

 

 

If your just boring it 30000ths over and not opening up the ports it really shouldnt affect your compression at all. As long as your rings seal properly after your break in procedure you should be pretty high with 20cc domes. I have the Noss Head with 20s and Im kicking 150psi in each cylinder at 1089 feet above sea level. Im sure if I got a brand new top end I would be a considerable amount higher. As soon as I either install my timing plate or get my Dyna FS(Havent decided yet) I will probably be in the high 150s range so I will run 1 gallon of VP110 To 3 gallons of 93. Better safe than sorry.

[wimpywade94]

cool, thanks guys.

wade

[bansheefreak]

why are you boring 30 over??? you shouldnt be boring unless its needed and your compression will be good cus you will basically have a fresh motor your just making the pstons bigger is all.. but boring should only be done if needed..