I was reading reviews on ARP head studs for the EJ25 motors (ARP part #260-4701), and one of them said that the studs were for the turbo only version of the motors, and one negative review stated that he used them in a non-turbo motor and they pulled the threads out of the block. Do the block threads in the turbo version have heli-coils installed or some other thread-strengthening modification that is not found on the normally aspirated engines?

You buy the ones that fit the engine. SOHC or DOHC.

But these are for people who run big hp.

Why spend over $100 on head bolts that don't need to be replaced on a run of the mill engine?

 

O.

No difference in the block thread or material between turbo and n/a that I'm aware of. There is a difference in the length of SOHC and DOHC head bolts, so the person complaining either installed the wrong ones, installed them incorrectly, or the threads in his block were already damaged.

 

I agree that there isn't much point spending the money for these unless you're building a high HP engine. Nothing wrong with the regular head bolts.

Edited December 14, 201510 yr by Fairtax4me

Ask ARP.

 

There's no need to use them though. The last person that bought new headbolts (also unnecessary) on here (or another forum?) had the gaskets fail shortly after.  trying some extra step or going "above and beyond" doesn't trump what is now two decades of experience in EJ25's. here's the recipe for repeated success if you ask anyone who has been doing significant EJ25 work for a long time:

 

1. resurface the heads

2. use Subaru headgaskets

3.  resurface the block faces if you want extra protection

 

 

one negative review

 

 

1.one negative review is usually an outlier, anecdotal, or holds little water on some other grounds. particularly with no details, history. 

2. using head studs on a stock EJ25 non turbo is questionable discernment to begin with.

Shocker - an over heated, limped along, oil caked, cheap craigslist special or

used auto dealer that came from an auction because it was overheated into the ground and traded in

EJ25D block someone tried to make work - i've never heard of such a thing!?!?  LM*O