Ok, i was just wondering last night...someone a while back posted something about using H22 pistons in a f20 bc they both have 87mm bores etc etc. That along with other thing(i dont remember what) makes a 2.4L. So in theory h22 pistons work in a f20 motor. Now Mahle Racing makes a FRM friendly low compression piston for the h22. So could i buy the H22 Mahle 9:1 pistons and use them in the F20 so that i dont have to resleeve the f20 block to get low compression pistons?
Thanks
Fadi

 

No, They will not yield a 9:1 CR. The compression height of the H22 piston is less than the compression height of the F20C1 piston. This affects the Volume at Top Dead Center, VTDC, and thus has an affect on the compression ratio (CR). You would have to run the numbers on it, due to the difference in compression height, it should cause the CR to change, of course the stroke is different on the H22 too so it may be wash. The only purpose to using the H22 pistons was the correct compression height and rod length for the use of the K24 crankshaft. If you are to reuse the F20C1 crank, than I believe that other companies may make a replacement piston for the FRM sleeves. If you use the K24 crank, the CR will be greatly inflated due to the increased stroke. In this case you would most likely need to specify your piston dish, in cc's, to a piston manufacturer to ensure the proper CR. Mine was a -13.5 cc H22 piston, with a stock head gasket, K24 crank, and with the cc's from my head yielded a 9.3:1 CR. But each application will be different due to head milling, porting and reworking of the combustion chamber etc...

 

i have a source for low compression pistons that are FRM Friendly - infact we helped develope them and spec using honda rings!

 

Do tell!

 

is that the same pistons you guys gave me that took a year and half to get??

 

just do the head gasket, way cheaper

 

no Rod - same company but your pistons are ment for much higher boost and a sleeved block.

 

ok.. just checking.. thanks for the update

 

any update???

 

i can not post in here - it will be delete, they will consider it a commercial post, sorry . I will get those pictures to you soon.