Ej22t hybrid interference or not

[ghia nut]

Hello, I have read and searched, quite a bit might I add.
I still can not seem to find the answer Im looking for sadly.

I have a 2005 wrx, and coincidentally, an ej22t sitting in my garage.
I would like to use the ej22t in the wrx wagon, along with a td05 16g. Subaru AWIC, reworked stock wrx injectors, catted upipe with EWG, and SRS turbo back.

It is to my understanding, that ej22t short block will mate perfectly with some ej20 heads.
I would need to use the ej22t head gasket along with ej22t wp and op and I assume a wrx gates timing belt. Are there better heads to use than the ej20g heads, if so let me know as Id like to purchase some eventually.

I understand that the compression ratio of these two components mated together would be around 7.5:1 please correct me if I am wrong.
My biggest question is if it will still continue to be a non interference or not. I just did the timing belt on the wrx as I thought I had a cam leak, and I really like the fact that if the timing belt/water pump/idle/tensioner/oil pump/or crank pulley decide to give up the ghost that I dont have to rebuild the damn thing. Ive been in a car that had non interference and the timing belt fragged and the engine just stopped running and died vs CLANK CLANK CLANK pssshhhhhh.

I know it sounds crazy, but I like the torque of the ej22t (the ej20 is ok but yeah) and a proper 2.5 sounds way out of my range and I all ready have a block.

[mike-tracy]

It will be interference. Since the ej series blocks are so similar, you should use a timing kit, water pump, etc for the heads you decide to install. Head gaskets I agree should be thicker ones.

There is some discussion here and elsewhere about using thinner head gaskets with a stock ej22t short block, but the ej22t pistons protrude out of the deck at TDC. Leaving no room for error on thinner HG's.

[ghia nut]

Is this due to head chamber design or valve length perhaps a combo of both?

[mike-tracy]

The reason is because the valves on the newer heads (at BDC) occupy the space where the pistons were at TDC.

The older SOHC heads had valves that were positioned in such a way that they could neither hit themselves or the piston at any point in the piston's stroke.

Now having said that, I've been into subarus for over a decade and have yet to have a single timing belt failure. I ALWAYS use new belts, tensioners and new or perfect shape rollers and waterpumps.

[wtdash]

Hi,
Not clear if you've got any of the '05 avl. to make this work, but....

If you want to use this in the '05 WRX the EJ20"G" heads won't fit your stock intake manifold and if you're using an EJ20G intake its sensors/harness won't work w/your '05.

I'm 99% sure the top-feed injectors in your '05 won't work in the side-feed EJ20G rails, either.

Best option: stock '05 heads/IM/injectors/harness on the EJ22T. Likely been done and covered on NASIOC.

GL,
TD

[ghia nut]

Hey thanks for the help
I'm essentially trying to build a 2nd motor for the car as I'd like to keep the stock engine for it in case things do go boom. I don't really think it's worth it to put new custom forged pistons in it as I dot want to get into well I'm doing this so I should do this then 3 years and 5k later and half finished block etc etc. would there be any benefit for running sti cams in this setup? And yes I do want to use the stock ECM

[Legacy777]

The biggest problem with going with newer heads is that you can't run the older intake manifold and stock ECU.