Is it possible to swap b16a (pr3) pistons into a b18a? I see that the bores are the same but I am not sure of wristpin length. If it is possible what modifications need to be done in order for the pistons to work. Also if they will work what rings should I use to install them (b18a) or (b16a)? Any info will be appreciated.

 

all b-series are interchangable (exclude b20b/z).....but at least most b16-b18 pistons are.....so yes it will work....wristpin comes only in the play when you use b16a rods with ITR/CTR/GSR pistons......as far as rings use b16a...

 

Ok well thats great. You don't have an idea of what kind of compression ratio I would have if I used these pistons along with a b16 head do you. I am guessing somewhere around 10 to 4 to 1 cause it would then pratically be a b16a itself. Well thanks for the info.

 

the compression is in the 10.0-4:1 range which would be right depends on the gasket used.....

 

Thanks again you have been very helpful.

 

I beleive that the rods are a little wider on a b18a and must be milled on the sides to clear the piston. After they would have to be shot peened to give back the strength. As for copression... who knows?

 

I am not sure if you have to have the LS rods machined for PR3 pistons. I have heard that they are plug and play, but I am not positive. I am using P73 pistons and I had to have them machined about 1mm on each side. As far as compression ratios go, if you are going the ls/vtec route with the b16 head and b18a block, the pr3 pistons will give you a compression ratio of ~11.5:1. If this is your daily driver, you may want to consider p73 (ITR) pistons. The USDM ones will yield about 10.8:1 and the JDM about 11:1 with a b16 head and b18a block. I went the safer route and got USDM ITR pistons.

 

The rods need to be machined and the compression ratio is 11:5:1 with the b16a head and ls headgasket.