ARP head stud/main bolt question, Who has had trouble with them?

[EsChassisLove]

I've heard of a few incidents where the head studs dont fully seat at the bottom, and they begin to fail at 1.3 bar unless torqued to 85lbs.

I've seen ARPs main bolts crack oil pans and stretch blocks.

So who has had trouble?

I'm just trying to find out how 2JZs can make 1000+ all day long with all ARP hardware but ARP head studs for SRs seem to fail at 550whp?

[Imarvin240]

you aren't supposed to have the ARP studs bottom out in the block. you take the stud and thread it all the way to the bottom and then do a turn or two back. people crack oil pans because the ARP main Studs actually stick a little bit further out then an OEM bolt, so you need to shave the pan down a bit where the stud would contact the pan. When you plan on pushing more then 500hp, you should probably bump up to the larger 1/2 inch ARP head studs for increased strengh. A 2JZ should not really be compared to an SR in how much power they make. 2JZ has more dispacement, more cylinders, and is made out of different material...not exactly the right engines to compare numbers. Hope this helped you a bit.

[EsChassisLove]

Has that been cleared up though?

I mean, did ARP take the time to re-design the main bolts for the rwd SR? Or did they just say fuck it and keep letting us alter their product?

[UNITEDMASTER]

All the main studs are the same length,so yes you need to shave the pan,its really not that big of a deal.And if your at the levle of building your own motor stuf like this goes with the turf.

[di-devol]

I just did mine, all studs in were "bottomed out" hand tight. If I backed them out a couple turns, shit would be way too high. Mains studs still hit the upper oil pan. We used locktite on the tips of the studs and fitted the pan. You'll see blue dots where the studs hit. I took a grinder to the studs until they didn't hit. It's super lame they can't make a couple studs a few mm shorter.

[Imarvin240]

i understand on certian engines, you may not be able to do the whole backing out a turn, but it is how its said to be done. reason behind it being that when you actually put the nut on and start torqueing down, you could force the stud to turn more and potentially damage the block if it were already bottomed out. Probably wouldn't really happen, but I bet they came up with backing it out a turn because it may have happened before.

[Kingtal0n]

i understand on certian engines, you may not be able to do the whole backing out a turn, but it is how its said to be done. reason behind it being that when you actually put the nut on and start torqueing down, you could force the stud to turn more and potentially damage the block if it were already bottomed out. Probably wouldn't really happen, but I bet they came up with backing it out a turn because it may have happened before.


besides the damage to the block, torque reading can be affected by the interference with the block. Are you tightening the stud evenly against all of it's threads or against the material at the bottom?

You are probably already aware but torque specifications differ depending on the lubrication used.
Motor oil typically has higher values than "moly" for instance.

[di-devol]

My instructions from ARP says "hand tight".

[Pinggg]

I just did mine, all studs in were "bottomed out" hand tight. If I backed them out a couple turns, shit would be way too high. Mains studs still hit the upper oil pan. We used locktite on the tips of the studs and fitted the pan. You'll see blue dots where the studs hit. I took a grinder to the studs until they didn't hit. It's super lame they can't make a couple studs a few mm shorter.

-Do you know which ones you have to shave down so i don't have to do that..

My instructions from ARP says "hand tight".

-That's correct.

[di-devol]

I always heard it was the last two on the flywheel side, turned out to be 5 of them. might of been just a little, but I wasn't taking chances lol.

[Imarvin240]

-Do you know which ones you have to shave down so i don't have to do that..



-That's correct.

all you have to do is exactly like di-devol said earlier, little bit of paint or something to mark the top of the studs with and then place the pan on and see which studs contact the pan. yes, hand tight is correct and that is also a great point di-devol, when I bought my head studs it did give directions on whether the studs had lubricant or not and on what type of lubricant.

[jr_ss]

Mazworx recommends to bottom out their studs before you trq them down. Their studs are also designed to bottom out in the block, preloading the threads. ARP's simply do not have enough length on them to do this. Keep in mind there are 2 different headstud sets available through ARP for SR motors. They utilize two different types of material and one is significantly better than the other. I run the Mazworx headstud kit in my VET.

[4sfed180]

ARP makes only one head stud kit of the sr20. The real sr20 head stud kit is made out of their higher tensile strength ARP2000 material. The latter kit is made for a VW Jetta 16v engine application. It is ARP's regular material. difference in torque is 10ftlb. The VW stud is 2mm shorter than the real sr20 kit. VW studs also come regular and undercut variety.

Depending what customer engine goals are and stud kit availability from suppliers I have used both kit without any issues.

as far as main studs. some block/upper oil pan castings will clear just fine and some will interfere. i always check when I build motors and when the stud is too long I put it in the lathe and shorten it. Usually shortening the stud 1mm fixes all clearance issues. Cutting it with a grinder by hand is ghetto, but thats just my opinion. Maybe Im spoiled with access to a full CNC machine shop and lathe :)

[[email protected]]

The Arp's are fine till about 28-30psi then they are iffy with head lift. I tried to go up in psi but lifted the head but currently holding strong at 27psi.
Head studs hand tight all the way then torqued to 85-90ft lbs
As for main studs I'm using oem are those hold just fine.

[Imarvin240]

The Arp's are fine till about 28-30psi then they are iffy with head lift. I tried to go up in psi but lifted the head but currently holding strong at 27psi.
Head studs hand tight all the way then torqued to 85-90ft lbs
As for main studs I'm using oem are those hold just fine.

what size head studs though, the regular ARP head studs or the 1/2 inch.

[[email protected]]

what size head studs though, the regular ARP head studs or the 1/2 inch.

Standard size arp head stud kit Which I believe is 3/8th

[Prime]

From what I understood, ARP SR studs are made for the USDM FWD model, and not the RWD block our chassis uses. That is what makes the studs have that issue on the pan. As far as backing them out, it shouldn't be necessary as they will do that on their own as torque is applied. Studs do that, afterall.

[codyace]

http://www.codyace.com/albums/album448/parts52.sized.jpg

Only the back too, and it's only a little bit...essentially the depth of the allen key part works.



In regard to the headstuds, I've always put them in (Fwd included here) by hand, until the first resistance/bottoming out is felt, and left them be. Also have always used ARP lube (as that's what comes with the studs). FSM tightening procedure, and I do them in increments of 10 or so once you get them all started and hand tight with the regular wratchet. 85ft lbs here for final torque

[Imarvin240]

Standard size arp head stud kit Which I believe is 3/8th

might want to think about going to 1/2 inch if you are that close to the limit of those head studs.

[[email protected]]

might want to think about going to 1/2 inch if you are that close to the limit of those head studs.

Yea I'll go to L19 when I do another block but I have no need for more boost right now since I'll be tuning/dialing in the chassis etc.

But once I sleeve it and L19 then I'll go 35-40psi :hsdance:

[EsChassisLove]

So other than Cosworth which are $450. Who else makes L19 hardware?

[[email protected]]

For l19s your gonna spend 3-4 times the price of standard Arp's.
So unless your looking to be making more then 600-650whp the Arp's will do just fine

[SlideOrDie831]

what size head studs though, the regular ARP head studs or the 1/2 inch.

according to another thread, he isn't using 1/2 studs.

[import_z]

if you purchase your ARP main studs from mazworx, you won't have to shave your upper oil pan because they shortened the studs for you.

it is about 50$ more expensive thought :S

[JDS Performance]

No they have not revised the stud kits for the rwd sr
As for the Mains the back two need to be machined down...I sell them machined if you need some LMK
AS for the head studs...just drop a bb down the hole then install the studs..you never want to bottom the stud out on a aluminum block
I have been in contact with ARP and let them know all the issues and how to resolve them...but its just not going to happen...so that is why I started doing them myself to help others out.

[s14unimog]

I've had good success with them over 1.3bar; I typically run 1.3-1.5. I've also reused mine 4 times now. All still within length spec and have never experienced head lift; even with 9:1 pistons.

As for the main studs, those two will have to be machined down as already mentioned. I only added them for the "just because" reason.

[TheRealSy90]

Have fun stripping out the threads with the arp headstuds if you ever remove them.

Mazworx all the way.

[codyace]

No they have not revised the stud kits for the rwd sr
As for the Mains the back two need to be machined down...I sell them machined if you need some LMK
AS for the head studs...just drop a bb down the hole then install the studs..you never want to bottom the stud out on a aluminum block
I have been in contact with ARP and let them know all the issues and how to resolve them...but its just not going to happen...so that is why I started doing them myself to help others out.


Interesting trick there with the BB, however at a point wouldn't you still be doing the same with the bb, albeit over a much smaller area? I guess to a point it would 'spin' on the bb but I could see that putting a higher concentrate of pressure on a smaller area than the stud just bottoming out.

(thinking out loud)

Have fun stripping out the threads with the arp headstuds if you ever remove them.

Mazworx all the way.

That stinks it happened to you, but I've had quite a few without issue ever...I know this is odd to ask as I assume you did, but you did use the correct thread lubricant right?

[JDS Performance]

Have fun stripping out the threads with the arp headstuds if you ever remove them.

Mazworx all the way.

How its this? The only difference between Maxworx and ARP is the extra end so the stud doesn't bottom out....which is wh the bb will do as well.
But if you were to ever spec both of them out...the nave standard threads where the block has metric threads....

[s14unimog]

Have fun stripping out the threads with the arp headstuds if you ever remove them.

Mazworx all the way.

I've removed/re-installed my same set of ARP's 4 times now without issue. Remember kids, "Lefty loosy - righty tight" :cj:

[JDS Performance]

Also to add ... only finger tight - the nut is what get torqueed not the stud!

[JFoxx]

pretty much every bolt in my motor is arp....... love it, never had any bolt related failures.....

[JDS Performance]

Also to add what ARP says to torque the mains is too much - it stresses the block and will cause your main journals to need to be line honed or bored.
I final torque them to 60 ft lb with no issues and no line honing needed.A BB on the mains would be good too but as we all know there is a height issue already and this would require machining all the studs!

Also too add after you machine (or use mine) the rear main studs there is no allen hole anymore so be sure to chase your holes with a tap and use the ARP lube - doing so this way you should have no issues threading them in by hand.

[ForeignMuscle]

ARP main studs are just a waste, period. I can give a handful of examples of people making in excess of 600whp with OEM main bolts. I use GTiR mains that are supposedly a little stronger. They don't need to be shaved, you don't need a line bore, they don't distort the main caps, and they hold just fine.

ARP head studs are iffy. Some have no problem, which most of us don't make stupid power. I think above 400-500hp and you are pushing it. I will have nearly the same setup as Santos (except a 58mm turbo) and I'm just going to buy the Mazworx head studs and hope that holds 30psi.

A lot of the confusion with ARP is the fact that stores were selling VW 1.8 liter head studs to people as sr20det studs. They are a basic ARP material and not very strong from what I've read. The ARP part number for the sr20det is #102-4701.

[ForeignMuscle]

JDS- I'm pretty positive that ARP says "Do not use lube in the block threads." That's definitely what my instructions read for the head studs anyway.

[JDS Performance]

Yes I think the VW ones were the undercut ones...which IMO is a good idea so your not bottoming out on an aluminum block but they are just not strong enough.
You are right about the GTiR mains being stronger but they are really hard to find these days - the stockers are good up to 500rwhp - but of course I highly doubt this has been R&D to its full potential.
IMO ARP stuff is ok and better than stock - yes you need to modify them to work properly - but thats pretty much all aftermarket parts.
I would never pay more than $100 for a set of studs - unless they were made from Titanium - that is just crazy.
If you are running around 450rwhp stock stuff will be just fine - as long as they are within spec and your using oil and properly torquing them.
With all this said - ARP has sponsored my SR Build DVDs but I will not disregard the truth in no way shape or form.

[[email protected]]

stock main FTW! only 30w oil then torque to the high side spec.

standard ARP headstuds hand tightwith moly lube till you cant anymore then with a allen socket give it a snug at the head of the ratchet till its stings the side of the wrist.
torque the head down in seq. to 90-95lbs

33psi holds solid

what people say will hold or power wise is just what people read on the net without first hand knowledge. i have seen this time and time again with different motor platforms just following others without seeking what best suits your set up.

[JDS Performance]

stock main FTW! only 30w oil then torque to the high side spec.

standard ARP headstuds hand tightwith moly lube till you cant anymore then with a allen socket give it a snug at the head of the ratchet till its stings the side of the wrist.
torque the head down in seq. to 90-95lbs

33psi holds solid

What head gasket, did you have your head and block mirrior finished?
How long have you ran this setup with no issues?
Also what stud kit did you use?
Just want all details that this works and holds 33psi with no issues

[ForeignMuscle]

He uses an Apex I believe, and he says the motor was nothing special. Just basic machining.
He uses ARP head studs. Standard 3/8"
And he has been raising hell all season long lol.

[JDS Performance]

Awesome this is good to know that they hold up and are reliable @ that psi

[[email protected]]

What head gasket, did you have your head and block mirrior finished?
How long have you ran this setup with no issues?
Also what stud kit did you use?
Just want all details that this works and holds 33psi with no issues

He uses an Apex I believe, and he says the motor was nothing special. Just basic machining.
He uses ARP head studs. Standard 3/8"
And he has been raising hell all season long lol.


here are all my details,
stock sleeved block
Wiseco .20 over pistons 8:5 comp
eagle rods
block was decked with front cover
ACL bearings
standard ARP headstuds SR20det's
stock main bolts
micro polished crank
stock DET head not even rebuilt. only resurance and hot tanked never taken apart
BC springs
stock retainers
BC272's
tomei intake cam gear stock exhaust gear
CS rocker arm stoppers
freddy intake manifold untouched
stock TB

used a cosworth headgasket with a T76 turbo but lifted head @28 psi on C16
replaced gasket with a cometic i believe and changed to a 6266. tuned at 33psi 595whp reving to 8100rpm on pump e85. has 2 dyno sessions,well over 40 dyno passes and 4 track days. my gasket just gave way and that was because of a 2step spike @35-40+psi at the track.

motor was put together summer of 2011 in my backyard with my daughter on my back wind blowing dirt all over no clean room here :wiggle:

[JDS Performance]

Yeah from the specs I was reading it sounded a bit thrown together but if it works it works!

But to conclude the cometic gasket gave out @35-40 psi - So I guess that is its limit.

[[email protected]]

Yeah from the specs I was reading it sounded a bit thrown together but if it works it works!

But to conclude the cometic gasket gave out @35-40 psi - So I guess that is its limit.

i wouldnt say 35-40psi because that was on the 2step and puts a major load on the motor.
on the dyno the motor seen 3-4 passes between 36-43psi without issues but that was only reving to 6k

[JDS Performance]

i wouldnt say 35-40psi because that was on the 2step and puts a major load on the motor.
on the dyno the motor seen 3-4 passes between 36-43psi without issues but that was only reving to 6k

So you think the cometic head gasket is good for over 40 psi? Honestly I find it hard to belive it holds 35 psi reliably.

[ForeignMuscle]

Plenty of videos on you tube of his car picking up the front tires. Just search sr20det 6266.
It's the light blue coupe..

[JDS Performance]

Plenty of videos on you tube of his car picking up the front tires. Just search sr20det 6266.
It's the light blue coupe..

Oh I am not doubting him at all - just getting real life specs on products.

[ForeignMuscle]

I understand. His car is sort of a freak for off the shelf parts and all that boost. I will have my results to post soon and I hope they are similar. I use an Apex head gasket though..

[[email protected]]

So you think the cometic head gasket is good for over 40 psi? Honestly I find it hard to belive it holds 35 psi reliably.

i wouldnt go and say that, on my dads old motor a 3tc we ran 43psi and NOS with a cometic gasket and when we pull the head we just copper spray the gasket and slap it back on.

mine went out with no load with 35-40psi on the 2 step.

my cosworth went out @ 28psi on a T76 C16 560whp 1 dyno session ( 10 pulls)

my cometic which SR people everywhere say dont work on SR's has 2 dyno sessions roughly 40 dyno pulls, 4 track days 595whp @33psi and has had 3-4 dyno pulls between 36-43psi @6k and held up.

i wouldnt say it was thrown together the head wasnt touched but my block is speced out the dirt and all checked good lol.

i have seen overlight built motors port/polished heads make less power then me, i just work with what i got maybe it a magic touch. lol :dead:

[JDS Performance]

I understand. His car is sort of a freak for off the shelf parts and all that boost. I will have my results to post soon and I hope they are similar. I use an Apex head gasket though..

Well you should hit higher boost with that HG I would assume...

[EsChassisLove]

My apex HG failed with my Darton sleeves. Just a heads up if your sleeves.

I'm just worried that 12k into this engine, and a stud will cause a failure.

It's a scary thought.

[ForeignMuscle]

I don't plan on having sleeves anytime soon if ever. I remember you having issues Eschassis.

I think I'll be fine up to 35psi. I'm only planning on about 540rwhp.

[JDS Performance]

My apex HG failed with my Darton sleeves. Just a heads up if your sleeves.

I'm just worried that 12k into this engine, and a stud will cause a failure.

It's a scary thought.

Did you get the head gasket bored out?
Also why and how could you have $12k in a motor build? Seriously I want specs!!!

[[email protected]]

Did you get the head gasket bored out?
Also why and how could you have $12k in a motor build? Seriously I want specs!!!


i have seen several people spend over 10K on builds, when they pay shops and buy a lot of things that their set ups/goals dont need. a lot of the VVL guys spend big $ for nothing.

building cheap and building smart are 2 different worlds

[EsChassisLove]

The only thing left stock/used in this engine are the cam sprockets and rocker arms. Well, the crank too but it's been polished. Lots and lots of high end parts put into this. I'm including labor btw. It's not just parts haha.

The HG was the correct size. The machinist said its happened before to sleeved blocks using Apex gaskets. Don't ask me why, I didn't question it and switched to Cosworth.

[EsChassisLove]

The only thing left stock/used in this engine are the cam sprockets and rocker arms. Well, the crank too but it's been polished. Lots and lots of high end parts put into this. I'm including labor btw. It's not just parts haha.

The HG was the correct size. The machinist said its happened before to sleeved blocks using Apex gaskets. Don't ask me why, I didn't question it and switched to Cosworth.

[Bentleyness]

i wouldnt say i had bad luck but i did snap a stud just TQing it to there specs. was bummed that i lost 120$

[JDS Performance]

Might want to get your torque wrench serviced or check your torque specs...if all that is good call ARP and they will send you another stud

[Def]

ARP main studs are just a waste, period. I can give a handful of examples of people making in excess of 600whp with OEM main bolts. I use GTiR mains that are supposedly a little stronger. They don't need to be shaved, you don't need a line bore, they don't distort the main caps, and they hold just fine.

ARP head studs are iffy. Some have no problem, which most of us don't make stupid power. I think above 400-500hp and you are pushing it. I will have nearly the same setup as Santos (except a 58mm turbo) and I'm just going to buy the Mazworx head studs and hope that holds 30psi.

A lot of the confusion with ARP is the fact that stores were selling VW 1.8 liter head studs to people as sr20det studs. They are a basic ARP material and not very strong from what I've read. The ARP part number for the sr20det is #102-4701.

What's the difference between the 102-4701 stud and the 204-4204 stud that everybody seems to sell as the SR20DET standard stud?

Edit - seems the 102-4701 is ARP2000 and the 204-4204 is 8740. But they both seem undercut. Is the Mazworx stud not undercut and ARP2000?

[jr_ss]

What's the difference between the 102-4701 stud and the 204-4204 stud that everybody seems to sell as the SR20DET standard stud?

Edit - seems the 102-4701 is ARP2000 and the 204-4204 is 8740. But they both seem undercut. Is the Mazworx stud not undercut and ARP2000?

Yes, Mazworx studs bottom out in the hole like the Greddy's and are ARP2000 material.

[JDS Performance]

The only difference in the "high priced" ones is they have more material on the bottom so the threads don't bottom out on the aluminum block - which as I stated before can be done with a BB

[Def]

The only difference in the "high priced" ones is they have more material on the bottom so the threads don't bottom out on the aluminum block - which as I stated before can be done with a BB

What about the fact that there are two "SR20" ARP part numbers? Are they the same beyond the material?

The Mazworx look non-undercut to me as well, which is a substantial difference. That said, you'll probably rip the threads out of the block before you run into big problems with ARP2000 undercut studs.

[ForeignMuscle]

People are not reading the complete thread. The two part numbers for ARP... One is the p/n for the sr20det, I listed that previously. The other is actually made for a VW 1.8T and it is a weaker material.

The ARP's do not touch the bottom of the block AT ALL. The collar around the top of threads bottoms out on the deck. This is the reason Mazworx made their style with the bullet end. JDS said you can put a bb in the bore and do the same thing. Sounds like it would work to me.

ARP's have held 700whp on plenty of builds so it doesn't seem to be a problem.

[Shift n Drift]

what exactly is a BB?

[TheRealSy90]

I just installed some VW 1.8 ARP's in a friends sr with no problems, final torque to 85 ftlbs. I did not install a bb and hand threaded them all the way down then backed out 1/4 turn per these instructions. These were followed exactly. My torque sequence was 10-20-30-40-50-60-70-80-85 following the recommended sequence. 240sxONE Tech » Blog Archive » SR20 ARP Head Stud Kit Install (http://tech.240sxone.com/603/sr20-arp-head-stud-kit-install/)


BB as in the metal ball you shoot out of a bb gun...

[JDS Performance]

If you don't use a bb over time you can ruin the block as the shaft on the stud is bottoming out on the block. Trust me i know first hand

[Frank_Jaeger]

Does the BB suggestion apply to KA engines too?

[JDS Performance]

Does the BB suggestion apply to KA engines too?

This trick applies to any stud bottoming out just be sure to check for clearance issues you may need to grind down your stud

[Shift n Drift]

ok so what is a BB

[cotbu]

Sheltered life?
http://www.rap4.com/images/products/BBBalls.jpg

[JDS Performance]

Yeah what kid didn't have a bb gun growing up? Don't give me the "I was a poor kid" because I was too and I had one!

[TheRealSy90]

So if you put a bb in there the bb is pushing down on the block just as the stud would, what's the difference.

[jr_ss]

Some of the stud holes on the SR block are open to the oil pan, so becareful dropping BB's down the holes.