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Sun Nov 06, 2011 8:40 am

Ever since halloween (my last hunting trip-loaded with gear and lots of 3rd gear climbs) I have been thinking about building a frakenstien motor to boost power out of my current EJ22 setup. The reasons I am contemplating this are:
A) It boosts the power from 135hp to 160 0r 170;
b) harness stays the same as well as all sensors; Same intake and reversed coolant manifold;
c) and finally costs. blocks are cheap

The build is very simple basically just replacing the current ej22 block with a ph1 ej25 block, using my same ej22 heads, intake, coolant manifold and harness etc. Putting the ej22 heads on the ej25 block raises the compression ratio to around 10.8:1 and increases displacement slightly to around 2.35.

I think the idea is the simplest for the EJ22 conversions to gain more power. I see potential downsides too:
increased compression means more heat, possible pinging
89 or 91 octane required
the ej25 block is known for rod knock
longenvity of this application in a vanagon is unknown

From what I read, the subaru brat crawlers love this combo because of the huge amount of low end torque it creates. Some builders of this enging complain because the ej22 heads just don't flow well enough, but those guys want power at 7k rpms and those heads just don't flow above 5500 very well.

Any thoughts? Anyone know of this application in a vanagon? David C, do you have any knowledge of this build?

Some Delta Torque Cams would really benefit the low end torque too.

Paul

Sun Nov 06, 2011 8:44 am

I have read up on this as well.

Funny I figured if I ever got my hands on a block I would do the same.

I got frustrated with the Subaru forums, just not the same type of people as over here on thesamba.

1 fear in the vanagon would be hard to hear any pingin with the exhaust all the way in the back.

Sun Nov 06, 2011 8:49 am

The rod knock is actually a piston rock. The piston skirts are too short and the piston wobbles. Most of the time it will go away when the pistons heat up.
They make better pistons for it.

The crank and rods are not as strong on the 2.5 DOHC motor.

I thought about going this route also and only would do it with better rods and pistons.

You also need a special head gasket, I think Cometic makes one.

If you have a 95 EJ22 a 2.5DOHC is a direct swap. I have put 2.2 in for blown 2.5, plug and play.

Jeff

Sun Nov 06, 2011 8:51 am

I wonder if going to a thicker head gasket would help the compression ratio, maybe keep down closer to 10:1. All the subaru forums talk about raising it even more, not really lowering it. like using .40 cometic gasket to get the compression over 11. Not sure at what level you have to worry about pinging. one guy stated at 10.8:1 he runs 89 and never pings.

I see blocks all the time, cheap. I friend has two, but I know one has a knock, and the other he put in his multivan, but it seized a 200 miles after his reubuild of the engine...don't know what went wrong with his build.

Paul

Sun Nov 06, 2011 8:58 am

jrobewesty wrote: The rod knock is actually a piston rock. The piston skirts are too short and the piston wobbles. Most of the time it will go away when the pistons heat up.
They make better pistons for it.

The crank and rods are not as strong on the 2.5 DOHC motor.

I thought about going this route also and only would do it with better rods and pistons.

You also need a special head gasket, I think Cometic makes one.

If you have a 95 EJ22 a 2.5DOHC is a direct swap. I have put 2.2 in for blown 2.5, plug and play.

Jeff

yes, I know about the piston slap inherent to those short skirted pistons in 2.5. after market pistons, with a special coating stops the slap, but I have heard many rod beaing failures on the 2.5. they have funky short rods.

so an EJ22 has a bullet proof bottom end, 300k miles is the norm, and plenty of people have 200k miles on their 2.5 - is it that big of a concern? Still probably way stonger than a wbx that gets rebuilt ever 120-150k miles.

Sun Nov 06, 2011 9:00 am

I'm pretty sure I have seen some with a later WRX STI short block.

On the Suby forums you defiantly have to use the search.

They do call it a "frankenmotor"

They think your mechanical ability is directly proportionate to the number post you have.

Jeff

Sun Nov 06, 2011 9:08 am

I would think with updated piston, rods and rod bolts and head gasket you would be good to go.

I think I remember now, they used STI crank and rods in a phase 1 block?/maybe??

I have seen a ton of DOHC with a window in the block from throwing a rod.

Also spun bearings on the STI.

Jeff

Sun Nov 06, 2011 9:20 am

I would look for the phase 2 2.5 block (99-05) They have the same rock soild bottom end as the 2.2. The smaller head gaskets change the timing a little. I know the turbo motors do not like that. The compresion can be lowered by dishing the stock pistons like the turbo pistons. And if you going the coat them its a 20 min fix.

The hole 2.5 dohc engine is a plug and play 97-99. the early intake uses most of the same injectors and sensors. Come on by and drop off the calipers for rework.

jcl

Sun Nov 06, 2011 9:24 am

Will the 2.2 head go on the phase 2 block??

Jeff

Sun Nov 06, 2011 9:48 am

a914622 wrote: I would look for the phase 2 2.5 block (99-05) They have the same rock soild bottom end as the 2.2. The smaller head gaskets change the timing a little. I know the turbo motors do not like that. The compresion can be lowered by dishing the stock pistons like the turbo pistons. And if you going the coat them its a 20 min fix.
jcl

I think going to the later SOHC 2.5 block with the ej22 heads raises the compression even more to 11.5:1.
Probably too high in a vanagon application which is always under more load - probably hard to control pinging with that high of compression unless the heads or pistons are worked over a lot like you mention.

The main reason to use the old style ph 1 heads is so I don't have to make up a new harness. Intake and everything else bolts right up.

I might try to get one of don's 2.5 blocks and mock it up.

Paul

Sun Nov 06, 2011 9:52 am

The 2.5 pahse 2 heads bolt on the 2.2 turbo motor so i dont see why the 2.2 heads wouldnt go on the phase 2 blocks. I know afer the 2005 sti the rods got an extra mm so the pistons have a shorter head to pin by 1mm. The ph2 heads are 56-58 cc and the 2.2s are 45-46 cc. the phs1 2.5s are 48-49 cc.

I know JE will make any piston combo you want but the cost would be about the same as getting a phase 2 wire harness done! Im mixing stock parts for costs.

jcl

Sun Nov 06, 2011 10:08 am

Small car has a package for you
I've driven one of these in a syncro...very nice...legal in Kalifornia too

Quote smallcar:
Please call us about our "High Torque" Subaru OBD1 engine, a 2.5L with 160 hp and 155 lb/ft of torque.
253-473-2474

Sun Nov 06, 2011 11:10 am

a914622 wrote: I And if you going the coat them its a 20 min fix.
What does this mean?

It will last 20 minutes? Cost $20? Can be done in 20 minutes?

Sun Nov 06, 2011 11:50 am

I haven't really messed with the 2.2 Subaru as all the stuff I do is just the phase 2 and newer 2.5.

The combo of high compression and smaller valves when you put the 2.2 head on the 2.5 seems like you'd need to run premium but you still wouldn't get all that much more power out of it with the small 2.2 valves.

What about putting the intake manifold onto a phase 2 2.5 longblock? It seems like it would fit although I've never tried.

The early dohc 2.5 wasn't the best motor, mostly because of the head gaskets, but that's fixable and you'd be able to reuse your old harness. That would probably make more sense than a "frankenmotor" and would probably make more power as well.

Sun Nov 06, 2011 12:04 pm

Vango Conversions wrote: I haven't really messed with the 2.2 Subaru as all the stuff I do is just the phase 2 and newer 2.5.

The combo of high compression and smaller valves when you put the 2.2 head on the 2.5 seems like you'd need to run premium but you still wouldn't get all that much more power out of it with the small 2.2 valves.

What about putting the intake manifold onto a phase 2 2.5 longblock? It seems like it would fit although I've never tried.

The early dohc 2.5 wasn't the best motor, mostly because of the head gaskets, but that's fixable and you'd be able to reuse your old harness. That would probably make more sense than a "frankenmotor" and would probably make more power as well.

Well that is were I am stuck - since I have a 92 ej22 - obd1 - the 2.5's are all obd2 is i understand it, that is why is the 2.5 block is appealing, you do not have to do any new wiring or splicing sensors. the frakenmotor is well documented - but mostly with phase 2 components. And remember, there isn't all lot of talk about this in the vanagon application, because all the suby tuners want more revs, more power, or turbo for rally racing...
The early 2.2 manifold doesn't fit on the 2.5 heads without a special adapter plate.

Sun Nov 06, 2011 1:09 pm

Franklinstower wrote: Vango Conversions wrote: I haven't really messed with the 2.2 Subaru as all the stuff I do is just the phase 2 and newer 2.5.

The combo of high compression and smaller valves when you put the 2.2 head on the 2.5 seems like you'd need to run premium but you still wouldn't get all that much more power out of it with the small 2.2 valves.

What about putting the intake manifold onto a phase 2 2.5 longblock? It seems like it would fit although I've never tried.

The early dohc 2.5 wasn't the best motor, mostly because of the head gaskets, but that's fixable and you'd be able to reuse your old harness. That would probably make more sense than a "frankenmotor" and would probably make more power as well.

Well that is were I am stuck - since I have a 92 ej22 - obd1 - the 2.5's are all obd2 is i understand it, that is why is the 2.5 block is appealing, you do not have to do any new wiring or splicing sensors. the frakenmotor is well documented - but mostly with phase 2 components. And remember, there isn't all lot of talk about this in the vanagon application, because all the suby tuners want more revs, more power, or turbo for rally racing...
The early 2.2 manifold doesn't fit on the 2.5 heads without a special adapter plate.

I'm in the same spot. Now that my syncro is a little taller, larger wheels, etc, I feel like I could use a bit more oomph, and since I no longer live in the Great State of CA I have a few more engine options. But I don't want to totally redo my OBD1 ej22 conversion. I'm interested in finding a OBD1 ej25 that I can use my same harness -- this has been discussed only a bit for the DOHC that I've found: http://www.thesamba.com/vw/forum/viewtopic.php?t=455835 and threads linked therein (actually I think you chimed in there too?)

The OBD1 small car 'high torque CA special' seems like the ticket if all connections are basically the same. Might be worth asking brian @ small car about it. Though the increase compared to DOHC 2.5 makes it seem a littler rarer. Anybody know what model/year these (OBD1 SOHC 2.5) came out of? http://www.smallcar.com/index.php?dispatch=pages.view&page_id=11

Sun Nov 06, 2011 1:34 pm

I'd imagine things have changed a bit since I investigated this about 5 or more years.
There was a guy on the subaruvanagon list that tried several times and and didn't get it running successfully.
I had those records saved, lemme see if I can find them.
There was an outfit in San Diego (Cleveland in it's name? ) that was selling these: 2.5 with turbo pistons to keep the compression down I suppose, and 2.2 heads. I was on the edge of buying one of them.

btw that motor at the time, think it was 2007, was around 1800

Sun Nov 06, 2011 9:18 pm

ok so the boat Im in, early OBD1 2.5 DOHC with low mileage, with blown head gaskets, Cam needs a regrind to put it back together. I kinda looked into the frankenmotor, What would you do?

Sun Nov 06, 2011 9:28 pm

Quote: the ej25 block is known for rod knock
longenvity of this application in a vanagon is unknown

???

I don't know where you got that?

The Subi short block didn't get any major change since the 90'

The 2.5L always had the same short block, same goes for turbo variation.

As for harness (it seem like it's the thing that is stopping you), the easiest of all is the SOHC 2000-04, it's a joke. The 2.2L is a monster to do compare to this one.

That said, starting 06 the piston slap is a thing of the past due to a new head/piston design. Harness are still 5 time easier to do compare to the old 2.2L. So why mess with that Frankenstein engine?

If you really want some real power go turbo, they can be found for about a 1000$ more or so (2.5L). But be ready to loose the wife and kid, you will spend weeks figuring how to install that monster into the vanagon engine bay. The turbo exhaust system can't be use at all, harness is twice the lenght of the late 2.5L, so many more components to control the turbo.

I'm staring one soon and like always I will keep you guys posted, for the firat time ever I will disclose every little secret about such a conversion... almost step by step. The engine is a 07 Forester XT, about 260hp.

Turbo problem:

-Highly modified header (Turbo location).
-complex wiring harness
-complex engine in general, turbo components have to be relocated, that mean air/coolant pluming.

Anyway, stay tune

Sun Nov 06, 2011 9:46 pm

I don't know anything about all that,but I was thinking getting the ECU modified for the EJ22 to get more torque.Is that feasible?

Don't they have aftermarket upgrades for the stock EJ22?

Bye!