Jump to content
Sign in to follow this  
jdmsilvia13

Sr20 Head Studs help pls

Recommended Posts

Hey guys!

I'm needing some SR20DET head studs, but have run into a problem.

It's been well documented that the off the shelf ARP head studs for SR are short and don't bottom out. Mazworx sell their redesigned ARP's to fix this issue, but after shipping this ends up at AUD$370+ >.<. Now JUN, like Mazworx, get ARP to produce their head studs, and I can get JUN for around the $300 mark, not much more than the ~$270 for off the shelf ARP's. My question is, is JUN redesigned to be the correct length and bottom out? Or is it the same short length as regular ARP's?

Thanks guys!

post-95619-0-24936800-1452409957_thumb.jpg

Edited by jdmsilvia13

Share this post


Link to post
Share on other sites

I run VW Jetta head studs. They bottom out and are 3mm longer than the normal sr20 arp studs. They also bottomed out.

Share this post


Link to post
Share on other sites

for all the trouble why dont you just pay a little extra to get a better product from Mazworx just my 2 cents

Share this post


Link to post
Share on other sites

for all the trouble why dont you just pay a little extra to get a better product from Mazworx just my 2 cents

 

If the JUN is the full length, then it is the exact same as Mazworx for cheaper, plus the brand has +74 more JDM cred.

Share this post


Link to post
Share on other sites

I hadn't read about the head stud bottoming out issue. Is that a big problem? I was under the impression that many people used the off the shelf ARP head studs without issue and they're meant to be stronger than the OEM ones.

Share this post


Link to post
Share on other sites

ARP know about the issue and fixed it, SR-specific head studs are now the right length

Share this post


Link to post
Share on other sites

Personally I went Mazworx but then again I'm a sucker for nipples. Got head at the same time though so made freight more palatable :-)

Share this post


Link to post
Share on other sites

I agree with Rhino.

 

That is top service from Mazworx. ... usually it's the other way around with the supplier giving it to the customer from behind.

Share this post


Link to post
Share on other sites

Are the vw head studs considered still good for big hp? Compared to a stud made of 2000 material.

 

Also how do you tell if the sr20 arp specific studs are the redesigned longer items? Is there two different part numbers now old and new ?

Share this post


Link to post
Share on other sites

ARP know about the issue and fixed it, SR-specific head studs are now the right length

 

I just bought ARP2000's, did the model number change? Are they like the mazwork with an unthreaded portion at the bottom? Because mine are threaded all the way like the normal ARP2000's, maybe I got old stock :3

I managed to contact Jun and they told me theirs are the same as ARP, hence the arp2000's.

 

From what I hear most of the thread stripping issues are to do with the very very high torques (far higher than factory) ARP specify to tighten them to, presumably to keep the head down on extreme applications.

For my application (350rwhp, probably no more than 400rwhp later on) surely I can compromise to a lesser torque to be safer?

I mean, even at factory torque the ARP's should far outperform the factory bolts, right?

I was thinking halfway between factory specs and ARP specs, anyone have any recommendations regarding this?

Thanks guys!

Share this post


Link to post
Share on other sites

i sent an email off to ARP a few days ago, they responded and advised that the SR20 RWD 11mm studs have not been redesigned, they are still the same studs from years ago, they deem that the issue of the studs not bottoming out being an issue at all.

 

Capture.JPG

Edited by sinicysm

Share this post


Link to post
Share on other sites

Good to know. I fitted some a few years ago now and havent had any dramas, all torqued up fine studs In saying that im only making about 220kw atw so not exactly stressing it. I didn't realise people considered the studs not bottoming out as a problem being that i've rebuilt a few diesel engines where they dont bottom out. The tension is on the threads as they stretch so in theory as long as your more than 3 theads deep you should be seeing maximum strength. But hey ive been wrong in the past. Would defs get a performance engine builders advice if i was building a serious engine.

Share this post


Link to post
Share on other sites

Can anyone please advise RE whether using a torque midway between factory figures and ARP recommended figures is alright? I just watched Speed Academy's Project GripS14 installing the same studs and to get them up to torque was very sketchy and feeling like they were on the edge of stripping, don't want to be doing that, but at the same time is there something I'm forgetting about the different studs needing a lot more torque to work properly compared to the soft factory ones?

Share this post


Link to post
Share on other sites

Use ARP lube and recommended torque setting.

If there is fear of a thread stripping then it needs to be repaired prior to assembly.

Share this post


Link to post
Share on other sites

ARP uses 2x threads.. one for the engine side and one for the nuts

 

The nut side (top side) is a finer pitch, allowing for more clamp, provided you use the lube you will find with the same torque setting as OEM you actually provide a better clamp.

 

Some engine builders, actually over torque the ARP stud/nut combo way past what ARP recommend or OEM recommend in terms of torque.

 

 

I've actually taken the same approach on my RB25 and over torqued them all to 110nm, car loves 25psi all day and head no longer lifts.

Share this post


Link to post
Share on other sites

Do you need to remove the head to install the head studs? Or can you get away with just removing the rocker cover?

Share this post


Link to post
Share on other sites

for SR motors, covers, cams need to be removed

for RB motors, covers only, as stock cams have a groove cut into them for you to run a socket down

  • Upvote 1

Share this post


Link to post
Share on other sites

Cheers mate. Might do that when I have the cams & valve springs put in. And sorry for the little thread hijack haha.

Share this post


Link to post
Share on other sites

Hmm, so if I'm getting my cams and valve springs replaced, I should get the head studs replaced too?

 

If you can just pop out the bolts and replace with stronger ones in a star pattern without needing to remove the head or replace the gasket, that might be a good option.

 

Is it true that the main issues with running higher boost are the studs stretching and the head lifting? So the stock original head gasket itself isn't usually the problem?

 

Or is it very little extra labour to replace the head gasket too, and a much better idea?

Share this post


Link to post
Share on other sites

ARP studs have high torque specs; this so there is pre-stretching of the head studs so that they don't stretch further under pressure. I can't speak for quality of the factory studs.

 

If you want a new head gasket, you go the whole hog and remove manifolds on both sides, valve stem seals, have the head checked (if you're keen). This is a lot extra.

Edited by Luckytune

Share this post


Link to post
Share on other sites

Do you reckon you could re-use the original head gasket if you replace the head studs without removing the head? Or would that compromise the head gasket?

Share this post


Link to post
Share on other sites

Do you reckon you could re-use the original head gasket if you replace the head studs without removing the head? Or would that compromise the head gasket?

 

you can replace 1x stud at a time provided your head gasket is still in good condition.

 

S13 head gaskets aren't so good as they're composite paper (whatever they're called)

S14/15 head gaskets are of better material

 

I've done this to my RB25 and it still has the OEM gasket from 350 000 kms ago :)

 

 

Was going to do the same on my mate's car, then he decided to pop in a Tomei head gasket.

Share this post


Link to post
Share on other sites

Hmm, so you wouldn't recommend that for an S13? It's done 185k kms but no sign of head gasket issues. Might be too risky if it's a paper gasket?

Share this post


Link to post
Share on other sites

Does the ARP Head Stud kit 102-4701, suit all RWD SR20DET? Or should I just look into getting the VW Jetta head studs suggested above? Is there an associated model to go along with those that I should be looking for?

 

I plan on running max 22psi through an ATR28G2 with Greddy Easy Cams if that helps.

 

Gaz

Share this post


Link to post
Share on other sites

well if the compression is still good, better studs would reduce the likelihood of the head lifting even though it's a paper gasket

 

Does the ARP Head Stud kit 102-4701, suit all RWD SR20DET? Or should I just look into getting the VW Jetta head studs suggested above? Is there an associated model to go along with those that I should be looking for?

 

I plan on running max 22psi through an ATR28G2 with Greddy Easy Cams if that helps.

 

Gaz

 

I reckon just get the VW studs, they're cheaper and longer.. plus all my mates use them

  • Upvote 1

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

Sign in to follow this  

×