EJ22T Hybrid head gasket questions

[xbmxxx]

Ive searched and searched and cant find a definate answer, so just checking to see what you guys think.

EJ22T block with EJ25D heads.

I know using the EJ22T head gasket will yield a low CR, something like 7.2:1. I've read over on NASIOC everything from people using a 97-98 EJ22E gasket, to people running the MLS DOHC 25D gasket, and even a few running the single layer 2000 up SOHC gaskets. I would like to aim for a CR of 8:1-8.5:1.

thanks for the help!

[86BRATMAN]

You don't want to use an ej22e gasket for the 25d heads, coolant ports are wrong. Some say it works but personally I wouldn't, besides they aren't that much thinner than 22t. The 99+ ej222 gasket is pretty thin, but it is a 3 layer. Most places I have seen it referenced say it's .8mm thick, which would put your cr at 8.1:1, but leave you with .5mm quench height, which is on the tight side but workable.

[PhyrraM]

Nobody really wants to hear this. Maybe they are looking for a silver bullet or something? However, there are really only two options.

1. Use stock pistons and EJ22T gaskets and deal with the low compression. This leaves the quench at OEM specs. Read some old posts. The few folks who have done it report only a slight off-boost difference and no noticeable disadvantage once boost hit. IIRC, nobody has been sorry they tried it.

2. Custom pistons. It's the only way to put your compression ratio where you want it, and maintain proper quench height at the same time. I'll leave it to you to research proper quench height, but it's inexorably linked to proper timing and preventing premature detonation.

[xbmxxx]

It's not that I don't want to hear it, its that there are at least 25 people spread across 3 forums who all did different things all claiming its the best way to do it. Basically, I just want to do what is going to be best for a daily driven car with a TD05h. We have a good relationship with CP so getting pistons shouldn't be an issue, I was just sort of hoping to keep it all Subaru parts.

[xbmxxx]

this is one of the threads I found.

http://forums.nasioc.com/forums/showthr ... ?t=1896864

[86BRATMAN]

I've used the 542 phase 2 ej22 gaskets on a dohc ej22 before with no trouble, but it is na and high compression (eg33 pistons). I personally think it's your best bet short of aftermarket pistons since it has the correct coolant ports and bore size. There was no issue with timing belt lining up or intake manifold bolting on like some people have suggested in other threads because of the thinner gasket. This motor is still going strong after 25k miles in my buddy's 97 Legacy gt.


I didn't use oem subaru gaskets, but the Victor Reinz equivalent. After some research I found they were the original manufacturer of the gasket for subaru and I found them cheaper than dealer parts.

[xbmxxx]

yeah, I will be using 6 star (if I don't end up going Cometic)