2.2 heads on 2.5 block

[voulo5]

my brother was telling me about high compression builds and i coudlnt find much on them, but i guess one of them is using 2.2 heads on a 2.5 block. i was wondering if it would be a good idea to do this or is it a crappy mod or not possible. im looking to put my 2.2 heads on a 2.5 block i have sitting around, also wondering if theres other parts i can use form teh 2.2 that would work great on the 2.5.

links or comments are helpful ^^ 

[StripesRX]

IIRC usually the hybrid builds are with a 2.2 block, so you can run higher compression and 2.5 heads, that flow better than the 2.2 heads.


I may be wrong though

[BlackParis]

IIRC usually the hybrid builds are with a 2.2 block, so you can run higher compression and 2.5 heads, that flow better than the 2.2 heads.


I may be wrong though

Your right.

Unless you rebuild the 2.5 block with new internals

[boxersix]

2.2 heads can be used on the 2.5 block and will change compression.  Problem is it creates a sharp edge in the combustion chamber that's prone to cause pre-ignition.  This sharp edge is created from the transition of the quench pad to the HG surface, some odd 2-3mm worth, that's exposed from the EJ25's larger bore.  This edge needs to be softened a bit to prevent this.

 You're better of building a high comp motor the right way using appropriate internals with a good head/cam setup.

Adam
Rennessy Race Fab
Hunts Machine