legacycentral bbs

I bolted on my heads the other day, and the studs didnt protrude past the top of the nuts... I thought they might just need to stretch, but after re-torquing them every day, they dont stretch any more and they're sitting here:



Could they somehow be the wrong length??

The ej25 head bolts and the ej22 head bolts are different lengths.

IIRC, I had to use ej25 head bolts with the dohc heads because ej22 head bolts wouldn't screw down all the way....

You probably have arp ej25 head bolts???

I dont want to guess at what you should do, but maybe back out the studs enough to get the nut completely on there when torqued?

Ive got an EJ20G longblock using the ARP pre-99 DOHC head studs

Why didn't you use WRX ARP studs?

Because its a pre 99 dohc block... seemed logical to me

BAC5.2 wrote:Why didn't you use WRX ARP studs?

Unless I am mistaken, the Ej205 studs are shorter than the DOHC Ej25 studs. I think maybe he actually got shipped Ej205 studs.

Personally, I favour the OEM head bolts. If it's not going to have the heads off with any regularity, I see no point in studding it...

I found the box they came in, part # 260-4701... on the ARP catalogue it lists that as pre-99 DOHC

Goddamnit whats wrong??

I did some looking, and that's the shorter one. The 260-4702 is the longer stud.

I am 100% sure that the Ej205 bolts I have sitting around are shorter than the Ej20G bolts I have. You need longer studs. Sorry.

Just got off the phone to ARP... they said they only make two lengths for subarus, 7.7 and 8.5... I guess I could order the 8.5s and see if they'll work without hitting the cams...

What would be the way to do it, take out one stud at a time and replace it, or pull off the head and use a new headgasket?

Be safe. Pull the head and use a new gasket.

They shouldn't hit the head.

I'm a firm believer in head studs. They're just easier when doing head gaskets and stuff. With high output cars, expect to pull the heads for head gaskets every so often.

Sigh... just ordered new headgaskets.

My local scooby dealer can get them now at least

If they are bottomed out, they are too far, I think. When I put my motor together, I could have turned them in so far that they would barely protrude out of the head.

Sounds like you had the wrong studs too

they are supposed to seat

Well, now Im at the opposite extreme:





What do you think guys... too close for comfort?

The factory head bolts don't bottom out so why would the studs have to?

I didn't have to back mine out very far, ~ 1/2" or so. I haven't had any issues yet and I've seen 25psi.

What heads are you running?

I'm still using EJ22T heads. I hope to change that next summer though, and see how much of a difference in HP they will make.



I turned the studs out just far enough for all the threads on the nuts to engage.



I'm trying to put up a pic, but its seems photobucket has shit the bucket, for the time being.

Well Ive already turned the shorter studs, and purchased these...

Can you think of any problems that could occur with them being so close to the cam?

Theres about 1/8" between the top of the stud and the cam

I cannot think of a problem arising. With how strong of an alloy the studs are made out of, I wouldn't think they'd stretch much at all. You still have the headgaskets you already trashed? Try torquing one down and seeing what happens.

I don't know what else to tell ya.

actually
lol

I just thought of a problem...

how the hell am I supposed to turn the nuts with an extra inch of stud in the way? lol...

Deep socket 13mm 12 point? gonna be an interesting adventure trying to find one of those...

*hits forehead*


I'm surprised I didn't think of that either.



Here we go

Scratch that problem, my 12 point does fit over the protruding stud. Wicked.


PS - You're not supposed to store the rocker arms like that

The rockers were only like that for about 5min while I was puting the heads back together. I cleared out and repumped the lash adjusters right before that.

I'd say I'm at about 12-15k miles since getting the car running. I haven't had any problems yet *fingers crossed*

Hey Splinter, did you decide to keep those longer studs?

I'm trying to decide what head bolts/studs to use on my 20G heads + 22t block combo.

I used the longer studs, but after I stretched them and compressed the headgaskets, they do contact the cams in a couple places. After spending a long time on the phone with ARP, we decided the best course of action was simply to cut the top of the stud off with a dremel and a very think cutting disc.

He said another good solution would be putting a small ball bearing under the seat of the shorter bolts, which would be fine if you're not trying to get ridiculous amounts of power out of the engine. You loose a bit of threading in the block this method is the problem.

The problem with my method is that it becomes very difficult to remove the studs in the future.