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Frankenmotor question. Searched.


xbeerd
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Ok, so i have this 99 Legacy GT that needs headgaskets, i dont know how bad the PO overheated it. i got a 95 ej22e from the yard today for a good price.

 

anyways..

 

Will the 99 DOHC block with the ej22e heads cause this to be an interference motor? i read in a thread somewhere (and cant find it now) about the pistons making it interference in this case.

 

Can i just swap for other pistons to eliminate the case of interference?

 

is there a Frankenmotor bible somewhere on USMB or somewhere?

 

thanks guys!

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The Franken-bible is on NASIOC somewhere.

 

Pistons can be changed but the interference is still there. Even without the clearance over the deck the design of the piston crown would still make the engine interference. The only way around it might be to use dished crown pistons, but they would lower the compression ratio and that really just defeats the purpose of building a franker in the first place.

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Ok. So the only way around it would be to get a 96 bloock then? Did I read that right

 

(to obtain non interference motor)

 

Why would you want non interference? So long as you don't snap a timing belt, there's nothing wrong with an interference design; and they typically make more power as a result of better CRs.

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oh i was just thinking as i dont wanna accidently F my motor that i slapped together, thus, keeping the wife happy. i'm gonna get this ej22 running in the car first, drive it a bit while i fix my ej251 headgaskets in my loyale, then tear into this frankenmotor situation.

 

i like to run naked so losing the belt covers is desirable. but i might just slice the big cover so i can remove it easier if needed.

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Any 2.5 block will make it interference.

A phase 1 2.2 block with sohc 2.5 heads MAY be non-interference,(depends on valve opening height) but there again you lose the benefits of a Frankenstein unless you want to run forced induction.

 

If you want non-interference for reliability, just get a 96 or earlier 2.2.

 

Worst case if valves hit you get to pull the heads and put new valves in.

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I would just install the 1995 EJ22 complete as is, it's plug and play. if it was from an automatic then it also has EGR. then you got non-interference engine, one of Subaru's most reliable engines ever, cheap timing belt maintenance, more reliable timing belt tensioner (though that can be installed into any DOHC EJ25 if you swap the mounting bracket with it).

 

if you go with head swaps, it's such a large job - pulling engine, doing heads...might as well do it right and install a complete timing belt kit.

 

then install another timing belt kit at the next timing belt change.

do it right, maintain it properly and interference isn't too big of a deal, though i understand the desire to keep it non-interference if you can....in which case just install the EJ22 as is.

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yeah thats what im gonna do is put the ej22 in and call it a day. im just missing a few parts off of the ej22 (IAC Valve, Ignitor)

 

the engine is from the automatic, there are a few things tho im not sure about as far as the routing of some of the hoses but i got a 95 fsm which i should be able to find that in,

 

can i use the IAC from the ej25d? the napa parts search shows a different iac, but i see a iac other places, that looks like the ej25d iac, that says "90-99 legacy" ??

 

and ignitor too?

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found your thread....

 

not sure about IAC, if it plugs in and bolts in the same place then you should be fine. or just post int he parts wanted forum, those things never fail so they're worthless and folks have them lying around.

 

igniter should be interchangeable....the igniter though is on the vehicle body, not the engine...do you mean the coil pack?

 

posting pictures may help if you can.

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i would just use a 1995 coil pack even if you have to get a used one, simpler to keep everything as a 1995 EJ22 for future parts references....but I would have thought the Ej25 one is the same, no?

 

In any event coil packs are easy to get anyway, I'm sure I've got them lying around the garage.

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the ej25 one is a bit larger, the mounting holes wont even line up with the ej22 ones. im betting a coil pack is a pocket item at my local jy while im grabbing a few other items, it seems pretty pocketable (this JY is pretty spendy, so gotta get yer moneys worth.)

 

i'll hit you up if i cant find one.

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Any 2.5 block will make it interference.

 

I am not sure this is true.

 

Follow me here. The EJ25D pistons have a dish, about 4-5mm deep, across almost the entire piston top. Deeper dish than EJ22 pistons. AND, the EJ25D pistons are larger diameter than the EJ22 piston.

 

Why would a EJ25D bottom end, with EJ22 heads on it be interference?

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I am not sure this is true.

 

Follow me here. The EJ25D pistons have a dish, about 4-5mm deep, across almost the entire piston top. Deeper dish than EJ22 pistons. AND, the EJ25D pistons are larger diameter than the EJ22 piston.

 

Why would a EJ25D bottom end, with EJ22 heads on it be interference?

 

This is a good point. I hadn't thought about that before, but I do recall something about the 25D being interference because of valve to VALVE interference.

Could swear I saw a picture once of a 25D piston with dents in it from valve strikes though.

Are the valves in a 22 head any closer together? smaller? Compared to a 25D head?

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This is a good point. I hadn't thought about that before, but I do recall something about the 25D being interference because of valve to VALVE interference.

Could swear I saw a picture once of a 25D piston with dents in it from valve strikes though.

Are the valves in a 22 head any closer together? smaller? Compared to a 25D head?

 

25D heads the valves are closer to the piston tops, and at a steeper angle. That's why they hit pistons. Additionally, they can be valve to valve interference too, if the IN. and EX. Cams get out of time.

 

22E heads have a shallower angle, and a larger dome, so they sit higher from the poston. They seem to be a bit closer, and certainly not any further apart than the 25D heads.

 

 

I'm thinking it's time to slap a head on a block with some clay on the cylinder top, all the way at TDC and then rotate cam to open valves. Remove head and inspect clay impression to gauge clearance.

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yeah thats what im gonna do is put the ej22 in and call it a day. im just missing a few parts off of the ej22 (IAC Valve, Ignitor)

 

Theres a few different IAC's that all look similar.

 

90-MT = 2 wire. Only in 90 manual legacies. Annoying.

 

90 AT, and 91-94 = 3 wire with oval port.

 

95 EJ22 = 3 wire. some oval port, some round

 

96+ EJ22 = 3 wire, round port

 

96+ EJ25D = 3 wire, oval port.

 

all 3 wire are electrically compatible......match port to the opening on your intake.

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I'm thinking it's time to slap a head on a block with some clay on the cylinder top, all the way at TDC and then rotate cam to open valves. Remove head and inspect clay impression to gauge clearance.

 

Sounds like a plan. I'd do it if I had a spare 2.5 laying around. Take pictures!

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Theres a few different IAC's that all look similar.

 

90-MT = 2 wire. Only in 90 manual legacies. Annoying.

 

90 AT, and 91-94 = 3 wire with oval port.

 

95 EJ22 = 3 wire. some oval port, some round

 

96+ EJ22 = 3 wire, round port

 

96+ EJ25D = 3 wire, oval port.

 

all 3 wire are electrically compatible......match port to the opening on your intake.

 

Thanks for the info! the ej22e i have seems to run ok with the iac from the ej25d i took out. yaya.

 

only downer is that it seems my ej22e, based on the smoke from the exhaust now that i ran it with coolant in it, and the now lack of coolant, has a leaky headgasket too. F*** Me! (i previously started it up without coolant but only ran it for maybe 15-20 seconds just to see if it would fire, i made sure i had oil in tho, lol)

 

im gonna do the HG's on the ej22 and run that, keep the ej25d in the garage, and maybe pick up another set of ej22e heads (i know where some are locally) and over time do a frankenmotor. unless of course i pull the ej22 apart and its just f'd lookin inside. i like the idea of being able to take the heads off without disturbing the valve cover gaskets and ************.

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