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G'day all.

While I was cleaning up the EJ today I was wondering if it would be a good idea to re-torque the head bolts?

So, for and against and why?

Cheers

Bennie

for? because the correct torque on the heads will likely prevent warping

against? Each time you remove the heads you're supposed to re-tap the threads and replace the head bolts. Not sure if adjusting them requires the same treatment?

I wouldnt touch it because once you tighten it up with old head gasket you'll upset it and cause a leak due tiny movement of the heads - learnt my lesson about 7 years ago! (end result - had to change headgasket) Fair enough if the gasket is new, but old - I wouldn't.
Cheers
AP

ScubyRoo wrote:replace the head bolts

No you don't. They can be re-used.

Our workshop advises new bolts to be fitted but i just measured mine to make sure they hadnt stretched and re-used the old ones no problems to report so far 20 000 klms on them now plus the 355 000 klms they had travelled before, that was with new gaskets, as AlpineRaven suggests I dont think its such a good idea to disturb the gaskets at all
cheers

FROG wrote:Our workshop advises new bolts to be fitted

That was what I was advised by three seperate mechanices and subaru engine rebuild specialist, maybe they're just after my cash . But, I'm happy to pay a little bit extra for new bolts if it prolongs the overall life and gives me peace of mind...


Bennie I reckon if you're gonna fart around with heads, might as well do it properly and pull them off, get them checked and then reinstall with new bolts and gaskets - testing for head damage can also indicate other damage to the motor so might be a good way to check general engine condition before installing into Ruby without pulling it all apart? then you'd know your ej is sweet for a long while after...

The subi engine dude in frankston quoted me ~$350 for both heads, valve removal and check, heads clean, pressure test and machine, and valve refit. Didn't bother asking about gaskets and bolts as just getting a rough idea on cost for now.

If you know some history of the motor and know it didn't have gasket problems then don't stuff with it, as already said. Simply checking to see if they are the correct tension will do nothing.

If you have no idea about the motor, removing the heads will tell you a lot. Condition of the bore, valves and head gaskets are a good tell tale as to how a motor was/is running. Now, while the motor is out is the perfect time to find that it needs a set of gaskets, not once you have put it in and are wanting to drive it.

Okay - I understand that new bolts may be needed for a headgasket replacement BUT I am not pulling the heads off this motor, or taking the head bolts out... OB, I don't know the history of this motor, other than it has 127xxxKm on the clock when I pulled it. It also had a fried clutch and appeared to have a water leak at the waterpump area.

A test run on the shed floor (can be found in Ruby Scoo's EJ thread) found the leak to be there and the engine running very well without any water appearing in the oil after a few warm up/cool downs - Pick a part drain the oil before the car goes to the yard, so it had fresh oil for the testing.

So far today I've replaced the three front seals, pulled the cam shaft casing off the passenger's side to chuck some silicone on the seal between it and the head, re-sealed the driver's side head rear plate the same way and sealed the driver's cam cover - I'm about to go and do the same to the passenger's side before starting some work on the gearbox

I guess I'll check the torque (in the correct sequence) and go from there.

Thanks all for your input!

Cheers

Bennie

I work for a gasket manufacture / whole sales.

DO NOT RE-TORQUE YOU HEAD BOLTS IN ANY EJ MOTOR! or you WILL have a head gasket failure.

The bolts are what they call 'toque to yield' bolts or 'Stretch bolts' they are a one use bolt.
(If you want am explanation goggle it)

No gasket manufacture will warrant head gaskets if new bolts are not used.

My 2c worth...

Yeah, I read the torque settings for these bolts - 8 steps according to Haynes! Last two read "turn 90 degrees". Fat chance of doing that, I just wanted to check the torque...

So in the end you can't really do it anyway after its been done when the heads were installed last - unlike the EA's...

Cheers

Bennie

mate, if you're using haynes remember to cross reference with the '92 lib manual available from this forum - showthread.php?t=7011 I've found it goes into much more detail than the haynes and it's often had something thats saved me from disaster or made life easier...

ScubyRoo wrote:mate, if you're using haynes remember to cross reference with the '92 lib manual available from this forum - showthread.php?t=7011 I've found it goes into much more detail than the haynes and it's often had something thats saved me from disaster or made life easier...

Thanks Owen, I've got a copy of that from AP, the haynes was closer to reference....

How's your rebuild going?

Cheers

Bennie

Don't the EJ's use stretching headbolts? Well the new bolts my mate bought for his 91 Liberty EJ22 were stretching head bolts and thus you do it up to a torque and then go like 90 degrees more then leave it.

I'd only re-torque head bolts if they were new headgaskets and non-stretching bolts were used. Then also only after getting the engine to operating temp and then letting it cool.

As I said before, you don't need to replace the bolts.
Here's a Tech Bulletin from Subaru about it.

Category: Technical
Region/Zone: National
Date: 14th July 2006
Distribution: The Service Manager & Parts Manager

Reference: SIB-T-013-2005

Subject: Head Bolts for Impreza, Forester, Liberty, Outback and SVX

It has been suggested over the years that the cylinder head bolts utilised in Impreza, Forester, Liberty, Outback and SVX are torque to yield bolts (TTY bolts) and they require replacement every time the cylinder heads are removed and replaced.
The relevant workshop manuals make no mention of this requirement.
Fuji Heavy Industries (Subaru Japan) have advised that the cylinder head bolts for Impreza, Forester, Liberty, Outback and SVX can be reused and therefore do not require replacement every time the cylinder head is removed.

If your doing it on the cheap, don't change them.
If you want peace of mind, or the heads have been off a few times change them.

Well, it's been a few years, I didn't check the torque of the bolts back then.

4 years and about 100k km - now it's time for a head gasket change...

As always couldn't come at a better time... Fun fun - but I can't complain over all - I got 4 years out of these (most likely) factory head gaskets from a parts yard engine!

Bennie

I've never retorqued EJ head bolts. I would recommend just use Hylomar on the gaskets and make sure both mating surfaces and clean and oil free.

torque to yield bolts can be identified by the shape of the threads. ordinary threads have a sharp edge, torque to yield bolts are rounded as is the thread on the hole, so ordinary bolts cannot be interchanged. this is explained on the packaging of the gasket. the racing hq guys have the heads off the hqs every 2 or 3 weeks and have no problem reusing them, but i would not retorque after a long time, only if i had just rebuilt the motor and run it in, or whatever the packaging recommends. also don't think torque to yield bolts can be retightened as they are already stretched, you risk breaking the bolt.

Most of the performance engines I have built, I have used head studs so the heads can come on and off multiple times. I wouldn't use stretch bolts for race engines

tony wrote:torque to yield bolts can be identified by the shape of the threads. ordinary threads have a sharp edge, torque to yield bolts are rounded as is the thread on the hole, so ordinary bolts cannot be interchanged. this is explained on the packaging of the gasket. the racing hq guys have the heads off the hqs every 2 or 3 weeks and have no problem reusing them, but i would not retorque after a long time, only if i had just rebuilt the motor and run it in, or whatever the packaging recommends. also don't think torque to yield bolts can be retightened as they are already stretched, you risk breaking the bolt.

That's not right. Holdens 6 reds have 7/16 unc threaded bolts & are tensioned to 65-70 ft/lbs. All engines that I've seen with TTY bolts have std threads. Only one that I know of off hand that has different thread is one of the MAN Diesel engines has a buttress thread.

(Bringing this back from the dead)

>DO NOT RE-TORQUE YOU HEAD BOLTS IN ANY EJ MOTOR! or you WILL have a head gasket failure.

>The bolts are what they call 'torque to yield' bolts or 'Stretch bolts' they are a one use bolt.

From reading elsewhere, this is only half correct. They are torque to yield bolts, but they will then retract when removed and can be re-torqued again. Supposedly "some" TTY bolts used by other manufacturers are single-use (example: Dodge RAM Magnum heads for the LA engine, which I have), but the Subaru ones can be re-used with no issues.

(Edit: Sorry, missed page 2 which does sort-of provide confirmation the Subaru TTY bolts can be re-used. I guess the point is that TTY re-use varies from brand to brand)