Log in

View Full Version : High Compression Question



datdookie
11-22-2010, 02:03 AM
Quick question, how high would my compression be if i got a 2.5 block bored and honed to 100mm mated with 2.2 heads?
The reason why im asking is because someone is selling a 2.5 block halves thats been bored to 100mm. It'l cost me the same price range to get my blocked clean and honed, plus i cant split mine for some god damn reason.
Trying to get this project started asap because my car went out on me and wanting to get this dream started =)

So far i have:
-used ej22e dual port heads with delta 2000 or whichever is hp grind with a 5 angle valve job
-ej25d motor, which i already disassembled but cannot split the block.

So yeah, just wanting to know how high my compression would be, i know you can raise your compression with the size HG you get to.

Kiwi GT
11-22-2010, 03:14 AM
Stock pistons?

datdookie
11-22-2010, 08:30 AM
nah, its going to have 100mm oversized

Grafton
11-22-2010, 09:16 AM
if your going to use a different block that requires oversize pistons, do not use the 2.2L heads. get aftermarket high compression pistons and get the valve work done on your 25d heads you'll make more power that way and wont have to screw with wiring the 2.2L manifold in

datdookie
11-22-2010, 01:09 PM
Shit, well the heads for the 2.5 are long gone, plus my car is a 2.2, do i still have to deal with wiring?

Grafton
11-22-2010, 07:24 PM
ah i though you had a 2.5 stock, nevermind then lol

StatGSR
11-23-2010, 09:55 AM
make sure you get the right head gasket or else your pistons will bash into your heads.... and no, I'm not joking (providing it is a ej25d block).

Kiwi GT
11-23-2010, 01:23 PM
And make sure you use EJ25 head gaskets, not EJ22. Don't laugh, I've seen it done, and it wasn't pretty.

datdookie
11-23-2010, 02:02 PM
Thanks for all the info, i finally splot my block open! But i dont think im going to go with 100mm bore. Going to a machine shop on wensday to get it honed and cleaned.

Anyone know how much it should cost total just to hone?

Grafton
11-23-2010, 04:34 PM
look into my build thread in this forum ( mods make it a sticky lol )

for me is was a little over $100 to have my block honed.

as for head gaskets get the cometic "hybrid" gaskets in the correct thickness

what year lego do you have that this is going into?

datdookie
11-24-2010, 12:24 PM
the block is from a 97 outback, and the heads is from a 95 2.2 legacy/dual port