Conrad

1. they are a waste of money

2. standard head bolts are good for 500bhp easily

3. the tightening sequence is like trying to get into Fort Knox with a load of chinese whispers along the way

 

I assume you are / were both running the 12mm studs and not 16mm?

What torque, sequence, and gaskets did you use?

Also was it a calibrated torque wrench?

The fact that it is a new torque wrench means ****.

David

 

ARGH...

do a Google for ARP Head Studs

ARGH!

David

 

To remove all the possibilities that could have been implicated in this failure. With Scott having two similar failures on a similar setup, and head bolts working so well on the 2.0s for Bob and Harvey I'd rather go with stock Subaru stuff unless it needs to be changed. I suspect I have fallen foul of another "upgrade" which may not actually be an upgrade. Clamping force with studs may be higher but not as predictable and more susceptible to weakening over time than a stretch nut. As always I am learning as I go along and meet new problems, but I see no need to "fix" what does not break on Subarus with the risk of breaking it worse than it could've done to start with

 

The larger ones are 14mm not 12. Standard bolt is about 10.3/10.4 on unthreaded part.

Paul

 

I'm just ending up using what I feel comfortable with in the end.

I don't believe the Subaru gasket is at fault as the standard engines aren't losing them left right and centre at least yet and I would think Subaru have learnt from the earlier MY98 EJ25 gasket debacle. The ARP head studs are not supposed to need a retorque, but mine came off with only 50 Nm.

So I have three options:

1. I am unlucky
2. Torque was not correct initially
3. There is an incompatability between the Subaru HG and the ARP studs.

Seems odd to have to use the Cometic HG (but not the high performance one as that is not as good as the standard replacement one) with ARP studs to ensure no problems. Seems too random.

Bob and Harvey whilst not on 2.5s have relatively massive mileage on 2.0s running considerable cylinder pressures using only bolts. Good enough for me. The bolts should retain consistent torque over time.

I hear the standard bolts torque up in a very solid/satisfying manner compared to the ARP studs.

 

Hi John,

Sorry to hear that you are still having a few problems

Just wondering how you managed to fit ARP studs without opening up the block threads? I assumed that it would have to be drilled and tapped to 14mm, or whatever, to accept the studs hence you would not be able to replace the standard bolts easily?

Good luck with the rebuild.
Regards,
Callum

 

They are standard sized ARP studs that were used.

 

Simon

 

Oh Just realised the significance of this.

 

Hopefully my car is running again tomorrow

P1 suspension and iON turbo awaited.

 

Wallis,

I tried Googling ARP head studs the other day, but kept getting your home page !

Mark.

 

You're lucky. I accidently got a **** link instead.

 

Kat, whats the link to that **** site??

Rob

 

Rather amusing how humour goes over your head Kantana..

Rob.. believe me it is not the kind of **** site you would want to be looking at.. well I wouldn't but actually how do I know whether you might or not..

Do the search.. about 3rd down on the list..

Simon (Still in shock)

 

Running again.

Doing a 200 mile run in under wise advice as everything has been tightened which will place different loads on the internals and then change back to the proper oil and give it death again.

Can already tell it is smoother around town below 2000 RPM on slightly higher compression.

 

Sounds good John, hope the run in goes quick!

Simon

 

Whoop Whoop!

Johns A dancer!

Pissed again.

Steve.+

 

LOL, just done 100 miles on 1/4 of a tank.

 

What compreesion are you running now John?

 

8.6-8.7

 

Next 1/4 will be the only other 1/4 a tank to last 100miles in this car...

lol

Simon

 

Have a little oil leak (turbo oil feed, not engine thankfully), plus going away for a week and will then need mapping for the higher compression, so such fun is a little way off yet.

 

Well hope you have a nice time away then John.

Simon

 

leave me the lap top and I will get andyf to map it proper while your away

 

Oil leak from the oil feed to the turbo is torrential, head's thread is damaged, car is being flatbedded and thread will be helicoiled or similar At least I wasn't going to be driving it this week anyway

 

doh

thread is m12 fine for reference

Perhaps you need to find your lucky rabbit's foot or something

 

bit of a b@stard john but the oil feed pipe will have been off and on quite a bit , on those heads with all the engines they have been fitted to and the head removal last week.

 

I am a reluctant bonnet-opener at the best of times

Why doesn't someone make a nice black box that goes under the bonnet that I can just tune to 500 BHP from the comfort of my laptop?

Surely it can't be that difficult to separate oil, water, and trivial combustion pressures and keep them all in their own little cubby holes and off my nice exhaust wrap

 

With a decent satelite link you could map it from the comfort of your armchair at home