I have only searched for about 2 hours so far(so much overwhelming information to sort through) but I'm having trouble finding anything definitive about what headgasket to use or if customizing one is required. I've seen cometic mentioned in several places but haven't found any usable information about the headgasket I'd need. I have a '99 phase II ej22, cyl #1 rod bearing is toast. My guess is a phase I ej25 block is going to be easiest/cheapest to find quickly.

There is a lot more info on NASIOC for this and some that are still running the hybrid frankenmotor. I found plenty of info on it in about an hour but that was weeks ago.

 

Mike

unless it's something custom i would think you match the cylinder which is the block side - so you'd use an EJ25 headgasket. the heads are just flat metal, not a big deal.

 

i assume you've already found that Phase I EJ25 block is compatible with Phase II EJ22 heads?

Always match the head gasket bore to the block you're using and match the thickness to the piston (ie. if the piston protrudes the deck you need the 1.4mm gasket, if it is even with or below the deck you need either 0.8 or 0.6 mm gasket).

 

Maybe this helps? It's not perfect (some EJ257 numbers are wrong) but the older stuff is wel covered.

 

http://www.b4et.com/dosc/090618_ej_compression_ratio_matrix.pdf

They have part numbers over on NABISCO. Search for "frankenstein" and authors Storm or Matt Monson. They go into a lot of depth.

 

Jacob

Here is a ton of info leading up to what you want there are a few more threads about it and one of them has an exact part number specifically for the frankenstein motor ( hybrid) you do not use EJ25 or EJ22 gaskets. I think Cometic makes them but I ain't sure.. The few threads that I read fastinated me but that kind of project would be getting in way over my head... BTW the Dual port EJ22 heads work better. Dont P and P just throw some cams in there and go like he Double hockey sticks.

 

Mike

Here is a ton of info leading up to what you want there are a few more threads about it and one of them has an exact part number specifically for the frankenstein motor ( hybrid) you do not use EJ25 or EJ22 gaskets. I think Cometic makes them but I ain't sure.. The few threads that I read fastinated me but that kind of project would be getting in way over my head... BTW the Dual port EJ22 heads work better. Dont P and P just throw some cams in there and go like he Double hockey sticks.

 

Mike

 

The one thing I haven't found out (and perhaps this will further expose my ignorance of cars) is the benefits and drawbacks of the different bottom ends. For example, is a brand new 2.5i engine more desirable than one from and RS? Do all 2.5s fit?

 

Jacob

All 2.5s will work though the phase two yields better compression ratio and less likely for piston slap.

Yeah I saw the frankenstein thread on nasioc, tons of info but didn't come to anything certain on the HG. Most everything I've read says most head/block combinations work with a few exceptions. I have no idea how accurate it is but I've gotten the impression the single port sohc phase II ej22 heads yield a higher compression ratio than the dual port dohc phase 1 heads... which my case would be a lot less work than using the older heads: can keep stock intake and not have to mess too much with the wiring harness. The only other thing I haven't figured out yet is if the stock ecu will run the motor well enough or if more work is required there.