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Old 08-30-2006, 01:52 AM   #1
fastenova
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Question EJ25 HG Questions... Experts needed!

Hey guys... Looking for your opinions on Phase I EJ25 head gaskets and procedures.

What brand HG is the best for a good seal on a NA ej25 block (DOHC)? OEM (redesigned, obviously), or aftermarket... I've heard decent things about Felpro and Cometic, but not used either.

Did you retorque your head bolts after running the engine for a bit? I don't have FSMs and don't trust my Haynes all that much.

What kind of head bolts should I use? OEM/aftermarket?

Of course I want to make sure the mating surfaces are clean and perfectly flat, and all old sealing materials are gone, and there are no nicks, etc. What else do I need to do to ensure a good seal? Don't tell me to get a phase II block!!!

Thanks!
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Old 08-31-2006, 12:01 AM   #2
FuJi K
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When working with the Phase1 EJ25, you MUST get the PHASE1 headgaskets if you where to go OEM. The Phase1's pistons DO come out of the shortblock a tiny bit, SO if you plan on USING the PHASE2 headgaskets to gain CR, I advise you NOT or else you'd get piston slap, which is NO GOOD.

The PHASE1 headgaskets are made thicker because of this. ALSO it is the pistons that is why it has a lower CR 9.5:1 on '96 motors and 9.7:1 on the 97-99 motors; EJ25 so to speak.

I reused the headbolts. There is a procedure to tightening them. You go some like 90* with so much torque, you loosen it again, then tighten with another different torque setting but now 180*, loosen 90* on some then tighten the rest 90* or something. IF you skip a step, you'll noticed why some bolts are SO LOOSE. lolz

I used COPPER HEADGASKET spray, bought from AutoZone. The one I bought from NAPA wasn't good, it was fuzzy copper coming out of the can, not fine mists....

From what I HEARD about Cometic, is that because it's not sqeezeable and expandable like the stock HG, it's recommended that you use APR or stronger headstuds.

I've worked with '98 DOHC engines so the headgaskets are metal. the Replacements are mutilayer as well...but 2 more little layers I believe. I'm not sure if the '96 EJ25's used the composite or this mutilayer HG as well...My friend has a '96 EJ25 in his '93 Impreza L, SO when we happen to get around to taking his motor apart then we'll know. BUT I can also just go look at his motor and I can tell if it is composite of not. The PHASE1 EJ22E/EJ22T used the SAME HG from what I can tell. It is a reinforced/braced composite HG of very CLOSE thickness. The EJ22T piston just had a deeper dish thus having a 8.0:1 compared to the 9.5:1 EJ22E NA.
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Old 08-31-2006, 07:11 PM   #3
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Quote:
Originally Posted by FuJi K View Post
When working with the Phase1 EJ25, you MUST get the PHASE1 headgaskets if you where to go OEM. The Phase1's pistons DO come out of the shortblock a tiny bit, SO if you plan on USING the PHASE2 headgaskets to gain CR, I advise you NOT or else you'd get piston slap, which is NO GOOD.

The PHASE1 headgaskets are made thicker because of this. ALSO it is the pistons that is why it has a lower CR 9.5:1 on '96 motors and 9.7:1 on the 97-99 motors; EJ25 so to speak.

I reused the headbolts. There is a procedure to tightening them. You go some like 90* with so much torque, you loosen it again, then tighten with another different torque setting but now 180*, loosen 90* on some then tighten the rest 90* or something. IF you skip a step, you'll noticed why some bolts are SO LOOSE. lolz

I used COPPER HEADGASKET spray, bought from AutoZone. The one I bought from NAPA wasn't good, it was fuzzy copper coming out of the can, not fine mists....

From what I HEARD about Cometic, is that because it's not sqeezeable and expandable like the stock HG, it's recommended that you use APR or stronger headstuds.

I've worked with '98 DOHC engines so the headgaskets are metal. the Replacements are mutilayer as well...but 2 more little layers I believe. I'm not sure if the '96 EJ25's used the composite or this mutilayer HG as well...My friend has a '96 EJ25 in his '93 Impreza L, SO when we happen to get around to taking his motor apart then we'll know. BUT I can also just go look at his motor and I can tell if it is composite of not. The PHASE1 EJ22E/EJ22T used the SAME HG from what I can tell. It is a reinforced/braced composite HG of very CLOSE thickness. The EJ22T piston just had a deeper dish thus having a 8.0:1 compared to the 9.5:1 EJ22E NA.
LMAO! are you seriously trying to give advice here? short answer: buy the new OEM HG and dont be a retard, buy new head bolts.
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Old 08-31-2006, 09:41 PM   #4
Tim Sanderson
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Quote:
Originally Posted by gt_drifter View Post
LMAO! are you seriously trying to give advice here? short answer: buy the new OEM HG and dont be a retard, buy new head bolts.
Elegant,

I thought fuji K did a decent job of explaining quite a bit of stuff. Try to add helpful info without insulting people. You did'nt exactly fill in the blanks there either.

Fastenova, There's a thread started not long ago from burtonridr, Open up threads from a couple weeks ago in this forum and I think it's called head bolts or something like that. plenty to read in there.

If you search for head bolt torque(ing) you should find good info.

No need for new head bolts unless the job has been performed before.
No retorqueing needed unless you use aftermarket stuff, then you follow their recommendations.
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Old 09-01-2006, 04:08 PM   #5
gt_drifter
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Originally Posted by Tim Sanderson View Post
Elegant,

I thought fuji K did a decent job of explaining quite a bit of stuff. Try to add helpful info without insulting people. You did'nt exactly fill in the blanks there either.

No need for new head bolts unless the job has been performed before.
No retorqueing needed unless you use aftermarket stuff, then you follow their recommendations.

wrong, you should NEVER reuse suabru head bolts...ever. dont be cheap, do the job right. you may see ppl on here say to reuse them, they may even say they reuse them themselves, but they and anyone else lame enough to do that is only asking for trouble.

lol, i love it when backyard/garage enthusiasts give professional advice...man! there is so much misinformation on these forums...
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Old 09-01-2006, 04:24 PM   #6
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gt_drifter,
I don't have a clue who you are or where you get that gigantic chip on your shoulder, but you are obviously more interested in looking good than being helpful.
Directly from the MY00 FSM regarding cylinder head installation:

1) Install the cylinder head and gaskets on cylinder
block.
CAUTION:
Use new cylinder head gaskets.
Be careful not to scratch the mating surface
of cylinder block and cylinder head.
2) Tighten the cylinder head bolts.
(1) Apply a coat of engine oil to washers and
bolt threads.
(2) Tighten all bolts to 29 N.m (3.0 kgf-m, 22 ft-
Ib) in alphabetical sequence.
Then tighten all bolts to 69 N.m (7.0 kgf-m, 51 ft-
Ib) in alphabetical sequence.
(3) Back off all bolts by 180" first; back them off
by 180" again.
(4) Tighten the bolts (a) and (b) to 34 N-m (3.5
kgf-m, 25 ft-lb).
(5) Tighten the bolts (c), (d), (e) and (f) to 15
N.m (1.5 kgf-m, 11 ft-lb).
(6) Tighten all bolts by 80 to 90" in alphabetical
sequence.
CAUTION:
Do not tighten the bolts more than 90".
(7) Further tighten all bolts by 80 to 90" in alphabetical
sequence shown in the figure below.
CAUTION:
Ensure the total "re-tightening angle" [in the
former two steps], do not exceed 180".


Where does Subaru advise you to always replace head bolts? I have never ever seen it in print anywhere and own the FSM for a number of different Subaru models. I also work for a shop and have discussed it with the other mechanics here at length (with experience totalling in excess of 100 combined years of wrenching). There is not a single reason out there against reusing head bolts.

And next time you post, maybe try and be a helpful member of the community and not act like such an arse. It's fine to have disagreements with people and engage in technical debate, but the name calling and condescending approach just makes you look like some 14 year old kid who thinks it's neat to go post stuff on the internet and talk like a big man...
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Old 09-01-2006, 04:34 PM   #7
fastenova
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So as usual, I get conflicting opinions. So, let me elaborate on my story and see if I can get some sort of non-conflicting opinions...

I did HGs on the car 30K ago (About 130K). I did this work with the motor in the car. I used new OE HGs, and reused the head bolts. Had the heads totally gone thru, resurfaced, cleaned up the valve seats, replaced a couple of valves, and put all new seals in the motor. I also replaced lots of other little parts while I was in there (water pump, tstat, plugs + wires, battery, etc.) and the car ran awesome when I got her put back together.

Cut to today, 30K later, and same issue with leaking HGs, blowing combusted air into the coolant passages (Standard phase 1 HG problems)... In thinking about why it would have happened again, I figured either I warped the block the first time (because the car hella overheated) or I screwed something up when I put it back together. I know it would take a LOT of heat to warp the block, so I'm leaning towards the latter case.

I don't want to go through this again, and if I do, I want to be able to KNOW it's the block (maybe warped, or cracked cylinder, or something caused from overheating the first time...)

So, since head bolts are MEANT to stretch, and obviously this will affect torque readings and accuracy, I think I should use new ones. I also will get new HGs from Subaru, same as the ones I used (the redesigned ones) and cam seals just for good measure. Since everything else is only at 30K, I'm not going to replace it.

Remember that I want to be absolutely POSITIVE that I'm doing my part of this correctly so I can't blame myself. I'll be pulling the motor out of the car as I have access to a hoist and stand this time. I will NOT be in a hurry like I was last time, working in my driveway and at night (working two jobs during the day last time). I'll have a garage and bench and lots of room and tools to work with, and I'll have evenings after work to do it. I've got torque wrenches, and will be torquing EVERYTHING down to spec.

That all being said, what do you say? Am I on the right track? I just hate to throw 2K or more into a new short block and reseal of everything if my block is fine. I'd rather spend $200 now on HG and bolts, than 2000 in a month. My time is not a factor, as I love working on motors and it gives me an excuse to 'relax' at home instead of working late.
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Old 09-01-2006, 04:40 PM   #8
Matt Monson
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Simple,
Measure the mating surface on the block. See if it's within spec. If you don't have the specs, I can get them for you...
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Old 09-01-2006, 05:01 PM   #9
fastenova
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That would rock. Where can I get a shop-quality straightedge? Is that what I should use?
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Old 09-01-2006, 11:44 PM   #10
Tim Sanderson
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Quote:
Originally Posted by gt_drifter View Post
wrong, you should NEVER reuse suabru head bolts...ever. dont be cheap, do the job right. you may see ppl on here say to reuse them, they may even say they reuse them themselves, but they and anyone else lame enough to do that is only asking for trouble.

lol, i love it when backyard/garage enthusiasts give professional advice...man! there is so much misinformation on these forums...
Are you a subaru tech?

If everyone is so wrong, and lame, and retarted, why don't you stick around here and answer everyone's questions by the book and 100 percent correctly? If you are not willing to do that then you should keep your insults to yourself.

Prove that subaru head bolts should never be re-used! Please.
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Old 09-02-2006, 02:40 AM   #11
Outback Jack
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Quote:
Originally Posted by Tim Sanderson View Post
Are you a subaru tech?

If everyone is so wrong, and lame, and retarted, why don't you stick around here and answer everyone's questions by the book and 100 percent correctly? If you are not willing to do that then you should keep your insults to yourself.

Prove that subaru head bolts should never be re-used! Please.
Subaru head bolts are torque-to-yield, meaning that when they are tightened, they will permanently stretch by a tiny amount. They will also become slightly narrower and may also strain-harden.

But, none of these mean that they cannot be reused. Maybe they can, maybe they can't. It depends on the properties of the bolt material. A simple stress-strain curve could reveal if they were strong enough for several re-uses.

Don't listen to mechanics and their apocryphal tales with no theory to back them up. I know some who still think you can't put a car battery on concrete. Very few have more than a hands-on knowledge of metallurgy and most can't give you a coherent explaination of its simplest theories.
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Old 09-02-2006, 09:47 AM   #12
gt_drifter
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Quote:
Originally Posted by Tim Sanderson View Post
Are you a subaru tech?

If everyone is so wrong, and lame, and retarted, why don't you stick around here and answer everyone's questions by the book and 100 percent correctly? If you are not willing to do that then you should keep your insults to yourself.

Prove that subaru head bolts should never be re-used! Please.
retarted? you? naaaaaahhhhhh.....lmao

am i a factory trained subie tech? why yes i am. ASE? bingo.

look, ive told you the facts about subie head bolts. you cant reuse them. you wanna go ahead and press your luck? knock yourself out.

sooner or later youll learn...and thatll make more work, and more money, for ppl like me.
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Old 09-02-2006, 09:50 AM   #13
gt_drifter
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Quote:
Originally Posted by Outback Jack View Post
Don't listen to mechanics and their apocryphal tales with no theory to back them up. I know some who still think you can't put a car battery on concrete. Very few have more than a hands-on knowledge of metallurgy and most can't give you a coherent explaination of its simplest theories.
LMAO. okaaaay, the ppl who built the cars says one thing, but this guy, with his metallurgy prowess, will set them straight...knock 'em dead, Leonid.
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Old 09-02-2006, 02:06 PM   #14
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Ahhhh! Stop the flame war, bring our soldiers home. Let's keep those in the Impreza/Legacy/Local forums... This is a technical forum, let's keep it technical. I appreciate intelligent debate, but don't be idiots and call each other names. That's what PMs are for

Back to the matter at hand...
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Old 09-02-2006, 02:30 PM   #15
Tim Sanderson
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Ok, I'm done.

Last edited by Tim Sanderson; 09-02-2006 at 02:39 PM.
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Old 09-02-2006, 03:47 PM   #16
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Originally Posted by gt_drifter View Post
LMAO. okaaaay, the ppl who built the cars says one thing, but this guy, with his metallurgy prowess, will set them straight...knock 'em dead, Leonid.
If Subaru said this, tell us what printed material contains this information. That's all anyone asked. Or is this just another thing that every mechanic just "knows" and passes to one another, like the belief that putting a car battery on concrete will drain it?
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Old 09-02-2006, 05:00 PM   #17
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I don't think it's possible to clean the surface of the block well enough while it's in the car. It's possible that the gaskets got borked while installing them in the car. I would bet money that the failure was NOT due to a reused headbolt. That argument has been hashed out many times on this forum as well as others around the world. What is required on other makes is not always required with Subaru. The FSM doesn't specify to replace the headbolts, it's not standard practice according to Subaru tech training and apparantly, there are ~thousands~ of motors running just fine with reused headbolts. If you want peace of mind, change them. It's not necessary but it can't hurt anything either.

I would personally go with Cometic gaskets. I like their construction better than the OEM design. That's just my opinion though....FWIW

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