JE Pistons

:confused:Hi guys I got a 09 legacy 2.5 non turbo and I'm trying to do some work. I know those cars have pistons with a bore of 99.5mm and a stroke of 79mm making a compression of 9.5 to 1. I want to know if a JE piston with 99.5mm bore and 79mm stroke doing a compression of 11.5 to1 would fit in the car without hitting the valves and if I have to do a new fuel mapping.

 

thanks to anybody who can help.

Yes you will have to do new fuel mapping. Yes this is a horrible idea.

Ej25 is an interference motor so you have to measure the cam lift and valve clearance.

Forged 2618 slugs in an NA motor with no Nitrous or boost is just a waste.

Even 4032 is over kill.

10.5 is pushing it. Our NA motors aren't power houses they don't work that way.

Simple idea is get an EJ257 have it balanced to .5g and swap pistons to some replacement oem Na pistons. Add valves cams mild port and polish rev it to 10k and enjoy,

At 11.5/1 compression, you would be hard pressed to find gas to drive it unless you run avgas or race gas. You'll have knock issues like a monster and really find out how much you can make the cylinders move around in the block.

 

Rebuild it to stock, put a header and CBE on it, enjoy good gas mileage and a bit of sound and do some cool wheels/suspension work on it. Drive it and enjoy it and never worry about a banjo bolt filter clogging up and taking out the turbo.

Thank you guys for answering my post it was very helpful. I imagine about the knocking problems and fuel mapping. Thanks for the idea of the EJ257 I will use that one. I got one sitting in my garage thank you