Quick EJ20g RA heads on EJ22t questions...

[my3awds]

My brothers ej20g v1 ra motor blew a piston ring. So I bought back my old ej22t shortblock and plan to put the ej20g ra heads on that. Just wanted to quickly verify with you guys:

Ej22t Headgaskets
Ej20g headbolts
Ej20g waterpipe (?)

And then transfer everything over from the 20g including intake mani, injector & fuel lines, etc etc. Am I missing anything? Is compression ratio lowered? Head gasket thickness seems to be very close. We plan on keeping the RA ecu and running a piggy back like an safc for the extra displacement. Thanks guys.

[PhyrraM]

Pretty much it. There are a few minor evap port differences on the block to deal with.

I would run without the standalone and see how it goes.

[my3awds]

Thanks for the reply. I kept telling him to lay off the gas, especially with a Ver1 RA ecu on 91 octane, but I guess he couldn't help it. Bye Bye #3 ring lol. So this time, I plan on purposfully lowering his boost 2psi and richening his settings until we can monitor what's going on. I hope he'll be ok with lowered psi, slightly richer settings, and a new fmic until we can get a knock monitor and some form of data logger.

[BXSS]

Are you the same my3awds from rs25?

I'm pretty sure the compression will be very low on the ej22t/EJ20G hybird (?-about mid 7:1 CR) so you may actually get away with running your old boost levels if you can keep an eye on things to make sure all is well with EGT's, AFRs & knock!

[my3awds]

Yeah that's me. Does the headgasket have something to do with the 7:1? That's pretty low. Might not really be any different even if its a 2.2 upgrade with that comp being so low.

Thanks again for the tips

[BXSS]

I believe the combustion chamber size is what lowers the CR, the ej22t has 46.6cc, while the EJ20G's have 57ishcc c-chambers.

I've read about folks using the thin metal ej22e PII H/Gs to bump the CR up some but have never done this, & have read other folks write that they may cause probs - ???

The DOHC ej25 has 46.6CC heads, so I'd think the CR should be about right with those for low boost, but I bet Your RA heads have better components & flow which will allow for good power with real boost 25+psi...

[All_talk]

I believe the EJ22T heads are 40cc. Heres some math on the EJ22T with the EJ20G head combo...

Volumes

Swept - 97mm bore x 75mm stroke = 553.96cc
Deck - 0.25mm above deck = -1.85cc
Piston - stock EJ22T = 28cc
Gasket - 1.3mm thick EJ22T = 9.80cc
Head - Early EJ20G = 56cc

CR = (Swept + Compressed) / Compressed

(553.96 + 91.95) / 91.95 = 7.02:1

Thinner HGs are not really an option because the quench height will get very tight, 1 to 0.75mm is ideal, so you might be able to use a 1mm HG. Numbers...

(553.96 + 89.69) / 89.69 = 7.18:1


But I'm not sure the RA heads are 56cc

just some info
Gary