ARP Head Stud Torque

[Lextreme II]

I got a customer and his engine builder torque the 1UZFE 30 lbs plus 90 degress with W-30 oil. The engine is leaking motor oil severely. I just talked to ARP and they stated that the head studs (10mm) Should be torque as follow:

60 lbs with ARP Moly
70 lbs with W-30.

Please beware of this otherwise you will have very costly repair.

 

[stevechumo]

I think the head gasket material is important in torqueing the heads, too. The graphite head gaskets might be good at 60 or 70 ft/lb, but the steel head gaskets might need at least 75 ft/lb or even 80 to be secured.

 

[ed_ma61]

its to do with the material of the bolt only, the gasket plays no part in tourque sepcs. 10mm arp bolt = 60ftlbs w arp moly. oem bolt TTY are throw aways, and an engine builder tourquing TTY on arp is worth losing

 

[Arnout]

I think lextreme just sells crap bolt that they cannot take stock torque! :booty:

Sorry couldn't resist posting bullshit If you pay peanuts you get monkeys guys! Different bolts require different torque. What a dumbasses they don't do their research!

 

[XR8tt]

If using MLS type gaskets the milling has to be 100% smooth..
It may have nothing to do with studs or the way they are torqued ...

 

[spf_lexus]

I bought Lextreme bolts, didn't seem like crap to me. I torqued to 75 and no such issues. Lextreme bolts are ARP or OEM, I would think oem would take OEM torque.

 

[stevechumo]

This is my most recent experience with the ARP studs and the Cometic gaskets that I bought from Lextreme. I prepared the heads and block surfaces really smooth with a polisher. The block and heads have about 40K miles on them. I took the heads out in the correct sequence so I doubt the heads or block are any warped. They could be, but the chance is very small. I torqued the heads to 70 ft/lb and the coolant leaked the first time. I re-torqued the heads to about 78 ft/lb the coolant didn't leak anymore, although I boosted crazy. The compression test showed from 182-185 psi, which is near perfect. The manual says 185 psi. This is my first time using Cometic but I like the ARP studs with the high quality.

 

[XR8tt]

In some cases tightening, loosening and re torquing helps..

 

[Arnout]

what torque have people tried over here? I use 8 kgm (80nm / 60 ft lb) but after rechecking I think one of the threads on the holes is not perfect anymore. Anyone tried higher torque? I hear people talk about 100nm (which is pretty standard on M10 bolts btw).

 

[spf_lexus]

I under torqued mine the first time to 45ft/lb and it never caused a drip or burn and that was a lengthy 1500 mile trip. I did have a wet corner but never lost coolant, it went away once I retorqued to 75ft lb. These are M10's with cometics also.

What does everyone feel the max tq for M10's should be?

 

[Arnout]

I think ARP advices 70 ft lb (100Nm) for M10
Also I think it depends on the block being steel or aluminum or not?

 

[stevechumo]

I think ARP advices 70 ft lb (100Nm) for M10
Also I think it depends on the block being steel or aluminum or not?

It also depends on how flat & smooth the block and heads are. I torqued mine at 70 ft/lb at first, but they leaked a little. I then retorques them to 75 and there's no more leak. Remember this tq is for Cometic gaskets only. Stock or soft head gaskets should be holding at 45-50 ft/lb as recommended.

 

[ToranaJudd]

So what is the torque of the stud into the block using your hex key?

I gather the 75ft/lbs is for the nut on the stud...

+ when I install my shorter stud for the intake cam gear area and place the head on, the stud does not protrude thru the head. Wrong size stud or am I doing something wrong?

I gather I am supposed to postiona nd torque all studs, place head + gasket on, then torque done the nuts?

Correct me if I am wrong!

 

[XR8tt]

Nothing to do with 1UZ block ..
But my aftermarket Ford Dart block said to have studs about 1/2 a turn back from bottom of thread.. Said it was better to let stud centre itself..
Blind threads. The studs don't go into water jacket..I assume 1UZ is blind also..

 

[stevechumo]

So what is the torque of the stud into the block using your hex key?

Good question. There's no recommendation from ARP about this, from what I know. I just used the hex key and screwed the studs in without any wrench until they touch the bottom and with an addition of about 25 degree.

You can't really go deep on it because the stud will touch the bottom and you'll damage it. When you tighten the nut, it'll pull the stud straight against the threads and the entire unit will compress the block and head together. The nut will also turn the stud further if the stud isn't tightened enough.

when I install my shorter stud for the intake cam gear area and place the head on, the stud does not protrude thru the head. Wrong size stud or am I doing something wrong?

You're not wrong. ARP is wrong. ARP supplies that stud much shorter than the other studs. However, if you use other stud, it'll be too long for that hole and it'll touch the intake cam. That hole is about 1/2" shorter than the rest. Don't trust my memory. Measure it against the stock bolt.

You may chop off other stud and make it fit in there, without protruding too much. In my case, I used the stock bolt for that.

I gather I am supposed to postiona nd torque all studs, place head + gasket on, then torque done the nuts?

Correct me if I am wrong!

It seems you haven't done this before, so a repair manual is necessary.

Put the studs in, head gaskets on, then the heads on. Then tightened the nuts in the correct sequence from center out.

 

[cjsupra90]

The stud itself only needs to be hand tight in the block. If you tighten them too much, you risk distorting the top couple of threads..

I've never used an allen wrench to put them in, just clean dry thread and just finger / hand tight and I have never had one give me any problems even on a 1600hp twin turbo chevy 502 V8

 

[ToranaJudd]

stevechumo:

Thanks for your reply! Its helps more than you could ever beleive!

I have built engine before, but older stuff and never had stads before. Everything has been a bolt, so it confused me a tad.

Cheers too all for help!

Judd!

 

[TCuz]

Do the studs require preloading prior to installing the heads?

 

[Zuffen]

ARP say no.

But. Read Corky Bell's book on supercharging and he has a very good argument for torquing them down.

If ARP say no then I wouldn't.

I know mine are 1/2 turn off the bottom of the thread and they're holding 21psi OK.

 

[TCuz]

Thanks for the reply. I work with large power engines (+10000kw) with head studs, and these are always pre torqued. These pre torque figures vary but ensure that the stud is seated satisfactorily prior to main tensioning of the cylinder cover nuts. So I was just checking. Thanks Tom