well i have a question my friend has a b17a in his del sol and he is changing pistons soon. So i was thinking i have a b18b so ....... would i be able to put those piston in my engine to raise compression. How hard will it be? Woud i be able to swap pistons with the engine in the car how hard is that?

 

yes, you might have to shave a little off the inside of the piston or off the small end of the rod, yes it's possible to switch them with the engine in the car, you'd have to remove the head and oil pan then the oil pickup and windage tray and push the pistons up from the bottom

Will it be worth it? I dont think so

 

even if i get them for free? i mean it would raise compresion some?

 

I guess if you get them for free, but you need to find out if they fit the rods come to think of it I dont think they will because type R's dont, actually i've never heard of anyone ever using b17 pistons

 

ud raise ur comp about .5 by doin this..worth it NO..ud get .2 by changin to a 2layer head gasket which would be A LOT easier and cheaper...if u want to raise the comp..get some pr3s or p30s pr3 = 11.37 p30s = 11.59 ...this is approx .. other things apply...what layer head gasket..if the head has been shaved any CC work etc...but for the amount of work to swap out pistons..bcuz u dont want to swap pistons out without gettin new rings/bearings plus new headgasket fresh hone etc....think about everything..its not a simple swap out of pistons ... if u want it done correctly...

 

wait, what?

possible in the car? sure, ive done it like 10 times... but pushing the pistons up from the bottom? theres a crank in the way...

im sure u meant drop the piston/rods in from the top, just wanted to clairfy.

*EDIT*
you meant removal, not installation. i feel like a retard

 

lol we've all had those moments

 

ok. Thanks guy. I was just having one of those woudn't it be cool moments.

 

you dont need to shave thos pistons and yes they have a small dome on them just a tiny bit smaller the usdm itr dome and they will help your ls alot in the way of compression...

 

I would reccomend the P30 pistons, and a 1 layer headgasket copper sprayed, I have done it before and it yeild s a great compression on a LS. And the LS motor suffers from Low compression, compared to its VTEC brethren, with the added Compression and better cams, and better breathing Intake manifold, it will move.

Basically the LS comp. ratio is around 9.5:1 in stock form. With the P30 pistons, and 1 layer copper sprayed headgasket the comp. ratio would jump to 12.1:1 which would greatly benefit the LS motor, especially coupled with Cams, Better flowing Intake manifold, and Tuning. It would be a beast. That is my .02 cents.

Here is a link to experiment with B-series Comp. Ratio's:
ZealAutowerks - Honda Compression Calculator

-Braxton