iveasked this question before and never really got a soild answer but for every full c/r point you increases what would an avg expected increase in power be?

 

i dont thikn there really is a actual ave point you can gain... if its basicly stock and jusdt milling the head.. and taking off the a layer or 2 of headgasket and doing the piston only... you can try to base it off the stock compression ration oh honda motors.. make sure you stay with in the same displacment .... which is prety simple.. IE first gen b16 10.2:1 = 150 second gen 10.6:1 = 160 i think dont quote me on that ... im not sure if those are correct numbers... but oyu get the point

 

so if i took my stock LS head and block which is 9.2:1 and raised it to 10.2:1 i would net close to 20hp?

every comp ratio point increase power by almost 20 ponies, i didnt think it would really be that much

 

Its really not that much.....

 

best thing to bump compression would be to swap pistons, and add a high compression headgasket.

good pistons would be b16a2 pistons with a 1 layer headgasket. give you around 11.5:1 CR
you will get more torque, but maybe gain 5-10 real hp.

 

damn so keeping an LS head and having 11.5 comp would only net 5-10hp...ouch i would have thought it would be more than that

how would bore size of a B motor affect overall output, i mean if the stock bore is at 81mm and it puts out 142hp what could i expect for a gain by bumping up to say 84mm

yes i know id have to resleeve the block and buy expensive overbore forged pistons

 

if you are getting into all that, why not get a b20 bottom end and swap in some forgerd pistons like wiseco. Then you achieve a large bore, have forged pistons, and havent altered the stock casting. i would say it would be relaible, and a more worthwhile route. I am planning to do something similar while i save my money for a vtec swap.