So a while back.....I tried putting a 2.5 crank in a 2.0 block.

 

Problem shows immediately that the 2.0 pistons come out of the block by about 13mm because you have to use the 2.5 rods, which are too long.

 

 

So flash forward....there is a thread about EJ20 pistons in an EA block, and it got me thinking.  EJ20 and EA82 pistons are the same size.....and EA82 and EJ25d rods both have  48mm big ends.  And EA rods are about 12-15mm shorter than the EJ25 rods.

 

 

So here is my idea.

 

EJ20 block

EJ25d crank

EA82 pistons, wristpins, and connectiong rods.

EJ22 heads.

 

92mm bore

79mm Stroke

 

9.5+ compression......should be a torquey beeach.

 

I'll take parts to the shop monday for some test fitting.

 

Anybody heard of this or done this?

 

I know you can get custom EJ rods and pistons to do this but maybe can be done with OE subaru parts?

That would be pretty badass if it works.  Would you need custom cams for that or do you think stockers will work?

So a while back.....I tried putting a 2.5 crank in a 2.0 block.

 

Problem shows immediately that the 2.0 pistons come out of the block by about 13mm because you have to use the 2.5 rods, which are too long.

 

 

So flash forward....there is a thread about EJ20 pistons in an EA block, and it got me thinking.  EJ20 and EA82 pistons are the same size.....and EA82 and EJ25d rods both have  48mm big ends.  And EA rods are about 12-15mm shorter than the EJ25 rods.

 

Doug wrote:

"about 13mm" and "12-15mm" It will be interesting what you come up with. I keep thinking you're going to need a short piston. However, if you need another 1mm less compression height, you can use an EA81 flat top. And that should read, "about" 1mm, it may be a little less.

Doug

Edited December 1, 201312 yr by Quidam

"about 13mm" and "12-15mm" It will be interesting what you come up with.

I keep thinking you're going to need a short piston. However, if you

need another 1mm less compression height, you can use an EA81 flat top.

And that should read, "about" 1mm, it may be a little less.

 

I got all the parts here at home to test fit a bit today.  Kinda anyhow.  I have EJ20 block, EJ25d crank, EA82 pistons and EA81 rods (which IIRC are the same as EA82)  We'll see.

 

Pics later.

The EA81 rod bearings aren't as wide as the EA82 bearings, one difference I know of. I bought a set of tri metal rod bearings for an 81 collection I have and compared them.

The EA81 rod bearings aren't as wide as the EA82 bearings, one difference I know of. I bought a set of tri metal rod bearings for an 81 collection I have and compared them.

 

Hmmm......

 

The EA81 rods do fit nicely on the EJ25 journal as far as side to side clearance.  If EA82 are wider they might not work.  As long as the EA81 and EA82 rods are the same length all should still be ok.

 

Headin out now

Well poop.  apaarently I recall incorrectly.

 

EA81 rods have a smaller crankpin end than EA82.

 

Gonna have to be EA82 rods, which I don't have any sitting out.....I gonna need to split a junk case to get some rods out.

 

On a better note....I found a spec for width of EA82 rods at the big end....19.35~.43mm

 

EJ Crank journals are 21.64mm so the EA82 rods will fit, albeit with a little excess side clearance.

No go.

 

Damn

 

Turns out the FSM's were confusing me.

 

The "crankpin" diameter of the crank itself EJ25d is 48mm

 

The "crankpin end" of the EA Connecting rod is 48mm.........without a bearing in it.

 

The crankpin itself of the EA82 engine is 45mm.....with a 1.5mm thick bearing.

 

Damn. 

In that case you might be in luck. You can have the crank offset ground to help with the difference in piston height and give you the correct crank pin diameter. This is done all the time in american v8's. The plus side is that depending on which direction you move the offset you may gain more cc's and stroke than the factory 2.5.

Are you sure? I put 81 pistons in an 82 block with the 82 pin for a test fit.

 

Ahh, the EJ 20. I have a car and I've been thinking of buying something like this with 4.44 5sp 190 hp.

 

"JDM Subaru EJ204D Non Turbo Complete Engine and 5 Speed AWD Transmission 2.0L
Complete and Clean Motor Set!
Approx 36K Miles
1998 Model
Compression tested at 130-135 PSI across all four cylinders
Pictures posted are of actual item and not sample photos!

*NOTE: THIS IS A 2.0L DOHC MOTOR WITH AVCS,

 

I'm thinking that's what I want. That cold? compression test, those numbers look low to me. What do you think.

 

'87 GL10 turbo wagon is what it would go in. By the time I source all the wiring ecu, and anything else looks like 2K might get it done?  What do you think? Just stock swap.

So for S & G I bolted an EA rod up to the EJ25d crank.....without a bearing....loosely cause I still need that crank.

 

Anyhow, here's another issue...these rods would be way to short.  This is one issue

 

And I have a feeling that even if clearanced out, the pistons would be pulled down out of the bores.  Would have to be longer rods, with shorter topped pistons.

 

 

On a side note.....I found out why the EA82 engine I pulled this piston and rod from was smoking SOOO bad when I pulled it.  Kinda intermittent.......but when it smoked it would just block out the sun for a minute, then clear up....then smoke again....... Non-turbo EA82 from 87 SPFI 2wd 3at wagon.

 

Wonder why????  Hint....those aren't broken rings in the backround.....they're broken RING LANDS

Edited December 3, 201312 yr by Gloyale

I've seen that before with the ring landings.  I think it's from a very much over heated engine!  Or an over revved one...  Not sure as one engine we pulled down and found damaged ring landings was severely overheated - blew the side out of a hot radiator when boiling!  The other was a parts yard engine that would smoke after off throttle rolling, the longer you were off throttle and rolling in gear the worse the smoke was - avoid big long hills!  I think this engine could have been over revved - it had been rebuilt once before by the looks of the piston heads used.

Cheers

Bennie

I think this engine could have been over revved - it had been rebuilt once before by the looks of the piston heads used.

\

 

Hmm.... I really don't think so. 

 

I pulled this engine from the car running......it had definately never been removed before.  And again, splitting it it seems for sure to have never been apart.

I was going to say ea82 pistons are known for having weak ring lands don't use them ej engine will tear them apart. You would be better off building a good 2.5 with some good pistons and h beam rods a 2.0 is fairly small

I was going to say ea82 pistons are known for having weak ring lands don't use them ej engine will tear them apart. You would be better off building a good 2.5 with some good pistons and h beam rods a 2.0 is fairly small

 

I was really thinking the long stroke/bore ratio would be good as Subaru engines are rediculously over square already so getting a bit more stroke, without really needing or wanting tons of horsepower really wanting a reliable low end torque motor.

 

Plus it's crap I had around to play with.

The phase one ej 2.5 with phase 2 ej 2.5 pistons gives you a stroker 2.5 this is probly the biggest torque engine NA that could be putt together without different rods / crank will push pistons up high and I had to use thick headgaskets but tons of bottom end torque Was to bad the NOS killed it was nice engine