head studs? Whats the best?

[Mike Neal!]

Where do I find TQ specs for the ARP's? I wonder if mine could just be re TQ'd?

[mike55112]

I beleive there 85 ft lbs.

[Shane@DBPerformance]

He doesn't know much about his motor, he bought the car modded. He is running running over 30psi of boost. He isn't knocking.

Pushing coolant under high boost, high load, higher power is common with the DSM heads even with no knock/detonation. They are not as rigid as the Evo heads and are prone to flexing easier. L19/H11 head studs and good headgasket usually fixes this and sometimes even when you just slap them in like Brad did. The Mistu MLS gasket for DSM is not all that good, the Evo MLS is very good. I personally think that normal ARP head studs might be worse than stock head bolts, but I could be wrong. If they are better, they don't seem to help much at all.

When the head lifts on a DSM under high load, you push coolant and it goes back down and all is fine until you boost again and push more coolant, or you push enough to get a big air pocket and start overheating, or you warp your exhaust valve seats from doing it too much. You don't want to fill up your coolant overflow and have it overflow onto your tires though at 100mph. When your head lifts on an Evo it likes to blow freeze plugs out of your waterpump or block, makes a big mess.

[TalonFiero]

30+psi for 50K miles on my stock HG and stock head bolts so far in the evo. no "Knock on wood"-alcohol!

[Kracka]

Originally Posted by Mike Neal!

Where do I find TQ specs for the ARP's? I wonder if mine could just be re TQ'd?

ARP's are TTY (torque to yield) studs meaning they're designed to be torqued/stretched once and NOT reused unlike popular opinion states.

[Shane@DBPerformance]

ARP's might be one time use studs, but I don't think they are TTY.

[4seasons69]

Originally Posted by mike55112

I beleive there 85 ft lbs.

it's around 80 or 85 with moly lube and 120 with 30wt oil

Originally Posted by ecoli

ARP's might be one time use studs, but I don't think they are TTY.

I've looked around a bunch and haven't found any legit info on them actually being tty. I've looked on arp's site and other forums and all I've found is people saying they are tty nothing from the actual manufacturer sayin they are tty. Infact i've found more info saying you can reuse them if they are NOT stretched. I've even found posts where they talking to the arp people and they said they were reuseable if they are not stretched

I think half the problem is people over torque them and when you stretch a bolt too much it loses a lot of it's clamping ability.
so you have a weakend headstud in an engine making a lot of power and the head lifts and you push coolant. correct me if I'm wrong but thats just my thoughts on it.

on another note I'm running arp's and a commetic hg and haven't pushed any coolant since I've put them in almost a year ago, even on the dyno when I had it tuned on a spike to 25psi then settling to 21psi and making 280awhp at db. ( but I know i'm not making a ton of power so we'll see how things hold up).

[blackrosenova400]

I dont know if I agree on this, are you sure these high load conditions arent causing alot of thermal expansion of the coolant? Its what it sounds like to me, because if you raise your head far enough to move combustion into the coolant, your headgasket is junk.

Originally Posted by ecoli

He doesn't know much about his motor, he bought the car modded. He is running running over 30psi of boost. He isn't knocking.

Pushing coolant under high boost, high load, higher power is common with the DSM heads even with no knock/detonation. They are not as rigid as the Evo heads and are prone to flexing easier. L19/H11 head studs and good headgasket usually fixes this and sometimes even when you just slap them in like Brad did. The Mistu MLS gasket for DSM is not all that good, the Evo MLS is very good. I personally think that normal ARP head studs might be worse than stock head bolts, but I could be wrong. If they are better, they don't seem to help much at all.

When the head lifts on a DSM under high load, you push coolant and it goes back down and all is fine until you boost again and push more coolant, or you push enough to get a big air pocket and start overheating, or you warp your exhaust valve seats from doing it too much. You don't want to fill up your coolant overflow and have it overflow onto your tires though at 100mph. When your head lifts on an Evo it likes to blow freeze plugs out of your waterpump or block, makes a big mess.

[v8klla]

Originally Posted by Swifty1638

Best headstuds out there are A1's. Shep, Rau and others use them. But, they are quite expensive...usually they cost around 600-660 a set.

Times have changed my friend

A1 Technologies H11 / L19 6 Bolt Head Studs $254.99

[Mike Neal!]

Motor blew up tonight.. weak.. now on to 2.4 I guess

[v8klla]

I'm sorry to hear that sir We are currently building about 8 different shortblock configurations for stock, let me know if you are interested...

[niterydr]

Originally Posted by Mike Neal!

Motor blew up tonight.. weak.. now on to 2.4 I guess

Then you'd have to change your avatar.

Tough luck on the motor.

[turbotalon1g]

sucky dude. 2.4 ftw though. Time to upgrade turbo too!!

[Mike Neal!]

I may just do a 2.3 so I may not have to change the avatar?!? Yeah I want to change the turbo but I may just try to get a new short block in and run this until next year as its already tunned (as of tuesday)

[sleepydsm]

Hmm, My coolant overflow dump tube is front of my drivers tire...

I have a Mitsu OEM headgasket, and it works OK for about 30psi.

I have a previous car with a MLS gasket, and it would push coolant. I switched to the OEM, and it was fine! Truely flat surfaces are key.

[santa]

Get your head decked, and block if possible. L19's and a mitsu multi layer head gasket and be done with it. I've been running that setup on my current car for many many miles. All this season I've been over 500awhp and have not pushed a drop of coolant. The cars never ran hot after a long hard pull, and I've been very happy with them(L19's).

[1ViciousGSX]

Simply stated, pushing coolant may be common, but it's not acceptable, and it's not a good thing.

What you have to realize is that what is getting pushed into the coolant are extremely hot gasses which over time will eat away at the head gasket and make it worse, call it a snow ball effect. Some instances will have eroded the block and head in that area if its bad enough.

If the tune is good, then I would suggest better studs than what you have now. If I remember correctly, the basic ARP's are only good to about 30 psi anyway, so get something better like the A1's or ARP L19's. May cost a little more now, but will save you money in the long run.

Also, I wouldn't use Rau's blowing a head gasket as anything negative about the A1 studs, he runs extremely high boost and cylinder pressures on that motor and eventually somethings gonna let go. In most cases 2 to 3 times the boost most DSM'ers run on their street cars.

I have the A1 studs. Is it overkill? Who knows? I don't think so as I plan to run 35-40 psi at some point in the near future. Just one less thing to worry about for me.

[Super Bleeder!!]

I thought i should add that when someone says X headstud is good for Xpsi boost, this is a bit misleading.

What you should be thinking about is the pressure in the cylinder (bmep) which is an actual function of horsepower, as opposed to boost which is relatively meaningless in this case.

[Pushit2.0]

Torque is your cylinder pressure then based on RPM you get horse power. There would need to be a long list of X's to make a list of what is good for what.

~John

[Goat Blower]

ARP's are just fine. I've used them and reused them more than once and have had no problems running 30+ psi. Like someone said, flat surfaces and a decent gasket are key, so is proper torque sequence and general care in putting things back together. From what I've seen on the other board, only the 750whp+ crowd is looking seriously at A1's. I doubt if that applies to many here.