5K Bore

[kpope18]

hi everyone, i want to bore out my 5k about 8 thou and put over sized pistons in but i have no idea about it should i do it, will it make much of a difference in power, (will it make a difference at all?) if i do it what else will need to be done.

 

oh and what else can i do to the bottom end to give my 5k more power?

[Figjam14]

8 thou wouldnt evan be worth it i would atleast go 20 or up to 60

[kpope18]

so 60thou will give me a descent amount more power?

[philbey]

No. Of it needs boring, go up to the next size, which is 20 thou. There is no point boring too large, you will gain almost negligible power. The largest pistons you can get are 60 in 5k pistons so any damage in the future and you'll scrap the motor.

[kpope18]

ok cheers so does it go 20 40 60 or does it go 20 straight to 60? and then what pistons would i need for max power?

[nerfbat]

generally the common ones are +0.010", +0.020", +0.040", up to +0.060" mate, yeah

Edited March 31, 2012 by nerfbat

[philbey]

When I bought my pistons they had 20 40 and 60 don't think they had a 10.

[nerfbat]

cool mate.

[altezzaclub]

Nothing you can do to the bottom ed to give more power, but you can make the power more efficient by lightening the flywheel and balancing the whole rotating system. If you were building a racer I say lighten the crankshaft too, as lightening the rotating mass means the motor spins up faster.

 

The increases in power come from the breathing, so better carbs & inlet system, a better cam grind, a better exhaust manifold and pipe system, and higher compression. Same thing, if it was a racer you could change the porting, the combustion chamber and re-shape the valves, but its not worth it for a road car.