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ok, i KNOW this has been covered before, probably hundreds of times. but, i can't find any definate information on it. i am rebuilding my ls motor, and figured i could us pr3 pistons to boost the compression, then add some forced induction. now, from several different people, i've heard mixed thought/opinion/theorys. i want to know, will i have to get machine work done to fit the pr3 pistons on my stock pr4 rods? i know for the gsr pistons i do, but for the b16? any help or guidance in this would be greatly appreciated. THANKS!

 

They both use 21mm wrist pins, so the pins that should come with the piston will be good.

in other news... are you planning on running forced induction with pr3 pistons? depending on a few things your looking at at least in the 10:1 range, moreso nearing 11

 

the higher compression kinda bothers me when it gets as high as 11. but, 10 i think i would be ok with a little boost. and i'm just looking at stock pistons, or a stock replacement pistons or something. not spending alot of money on this project, just wanna see what kind of numbers i can get with what i'm doing. thanks.

edit: now, are these pistons pressed on? or are they held on by clips? sorry, i'm a noob at engine building. lol.

 

pressed.

lets look at the calc and see if its something you want to do. http://www.zealautowerks.com/

A totally stock b18a/b with 3 layer head gasket and a head that has not been milled with those pistons will net you 11.39:1 compression ratio. Thats extremely high for forced induction, it can be done, but make sure your tune is GREAT and your going to be on low boost very high octane.

This is a more common setup for NA cars and a great match to a b16 head. More and more are doing the NA ls setups, but it really just costs a lot of money for small gains here and there that dont usually add up that well in the end(although it is cool).

if your just looking for a little bump in power, it would be fun. but you will have to tear into the engine again when you want to turbo.

 

man, that gives me a few things to think about. i am planning on boosting. stock head, stock block, stock pistons. basically a stock setup, except for the pistons. i want to run a 57 trim at about 10 psi. i was originally wanting to push the ls as far as i could get it. but, then i thought high compression, lower boost might net me more horsepower. i'd really like to try a high compression boosted setup, i think it would be pretty cool too. i'd rather not do rods and pistons, valves and everything. i'm trying to do this on a budget, so i'd like as much power (safely) for a decent price, know what i mean? and thanks again.

 

haha yeah im on the budget road myself. b18 crx. i have taken absolutely everything i can out of the car to lose weight since i cant afford to make more power right now haha.


High comp turbo would make some good power, but your tune has to be spot on, you would really be riding a fine line. And even if the tune is the best in the land, a slight stick of a wastegate, some poor gas, or even a really hot day could be bad news.

I would research if there are some cheap factory pistons that would work to give you stockish compression with more strength, there are a bunch for the D series, not sure what else is out there.


or get nitrous and smile until its empty hahaha. I've had it on an old car and it was just so much fun haha, turbo is great though, and i would love to try supercharged. INEEDMONEY! haha