Thread: Custom Pistons for JUN 2.2L Stroker

I don't suppose anyone else here has had to replace the 87.0mm bore pistons from the JUN 2.2L stroker kit (92mm stroke) with a oversized set of custom pistons?

We are in the situation where we need to find a replacement set of pistons to suit the 2.2L kit, but theres nothing available off the shelf. The JUN page (http://www.junauto.co.jp/products/cylinderblock-part/crankshaft/sr20.html?en) has some info but not everything I need to order a new set of custom CP's.

If anyone has ordered a custom set of pistons and has the vital specs like piston pin height, compression height, and other geometry I'd be interested in hearing from you.

Regards,
Kris

Just take the Jun Pistons you have and send them out to any piston company like J&E or CP pistons and have them match them.


The Jun ccrank is 92mm. The stock crank is 86mm. The diffrence is 6 mm of throw from top to bottom. Since the complete throw is from top to bottm you need to devide this in 2 since piston is traveling the xtra 6 mm , ( 3mm on the top and 3mm on the bottom ). This means the pin height will be moved closer to the crown of the piston by 3mm.

So the pin height is 3mm higher up into the piston over the stock pin height.

You know you need a 87mm piston so that is a given.

Next, are you running a NA or turbo setup and what compression are you looking for becasue you have not stated what this motor is going to be for.