head gasket

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gwhammy

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Sep 14, 2006
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I just had the head cut and put a new gasket on with the extreme-studs. The studs are a none stretch head stud and the paper says a 12 mm stud to 105 ft. lbs. of torque. I torqued in sequence from 60 to 80 then to 95 then 105 and checked all of them again.

Got it running today and drove it about 50 miles. Everything seemed good so I took the cold pipe out to set the 351 wastegate. Got it set at 30 lbs. hooked the cold pipe and took it for a drive. Ran it up to 40 lbs. of boost and pop, frickin head gasket let go out the front. Checks a few random studs and all were tight. It blew the first time out the side but the head took .015 cut to get it flat.

Any suggestions on what I could have done wrong? We will pull it tomorrow and lick it one more time. I just don't understand how it let go with a flat head, good studs and new gasket at that low of boost. I run more boost all the time on my 24 valve with stock head bolts and gasket with 329000 miles on it.
 
These are a hard stud like the good arp's. Machine shop that makes them told me to not over tork them. I ran them clockwise from the center out the same way I've always done it. Paper with them said to use a high temp grease. I'm thinking maybe something else. These have a washer under the nut like all studs, I understand the new arp lube is not as good as the old. What other kind of lube could be used. I'm headed to get a head gasket right now and tear it down tomorrow. Thanks for any help, I wouldn't mind if this is the last time I see the pistons on this motor.
 
Are you talking hi-temp grease, like wheel bearing grease? Get a proper thread lube (I've used the new ARP lube with no issues on my truck). Other issue I see is the 105 ft-lbs. Couple that with an improper lube, you're not seeing the full stretch on the studs that you should. 105 seems low anyhow. I'm not saying 145 ft-lbs, I've seen ARP's gall at that torque and wouldn't recommend it.

You check how much the deck on the block was out?
 
You didn't do a retorque after a few heat cycles. Bring em up to 120, drive a few times then retorque to 120 again when its cold. The heat cycles and head expansion will crush your head gasket more than you can get with just studs. Don't boost it until the retorque has been done a couple of times.
 
I found some high pressure moly with graphite assembly grease we used to use back in the 90's on race motors the machine shop sent with motors.I think this might have been some of the problem. I can get a machinist straight edge to check the block with. I hope that's not the problem. No I didn't do a retorque, but I will this time. I'm really thinking the grease I used wasn't good enough. How safe is it to over torque the studs?
 
I would torque one of the them up to 125 ft lbs on the old gasket and then pull it and see what it looks like. If it's stretched or galled, you'll know it's too much!

I too think 105 sounds too low, I personally would try at least 120 ft lbs.
 
Are you talking about the studs being stretched and the nuts galling?

Do the high dollar arp studs stretch when torqued. My understanding is these are the same metal compound as them. I hope I didn't waste my money on these. Does anyone know the torque specs on the 625 new age studs.
 
I got the head off, it blew in several places. None of the steel rings were blown or cut.I'm going to ask a stupid question, I had the head surfaced flat. Can the finish on the surface of have anything to do with the head sealing. This is something I just heard, have never heard it before on any motor. I am going to torque the head down tighter with the better assembly grease. Just want to cover all the bases before this thing goes back together.
 
Come on guys, you ain't going to hurt my feelings. I just don't want to lick this bi!ch anymore.

My thoughts are I've got some good assembly grease, torque the head to 130 and do some head cycles and retorque once. I am going to try these studs one more time. I believe the info from others is right the torque value seems to low. I talked to the builder today and he said they would be safe to 115 ft. lbs. of torque which makes me think they are good to 130 beings he is on the safe side.
 
yes, the finish can effect sealing. you can go old school and spray it down w/ copper and I'd run more torque.

105ftlbs on an exotic alloy on a 12mm stud? there wasn't any clamping force on the gasket :(
 
Here's what the plan is this morning. I'm going to torque it to 115 in steps, pull one nut loose and see if it's going threw the grease layer. If it looks like it is I'm thinking pulling each one at a time and relube them then take all of them to 125 maybe 130 not sure yet.
 
or get real name brand studs.... and actually try and seat the thing before going out and hitting it with boost....

ever heard of a retorque ?
 
I never said I was the sharpest rock in the pile. I had planned on a retorque, with the fuel and the fast spooling he351 in the twins it doesn't take much to pedal to get 40 lbs. of boost.

The studs torqued great, took them to 135 and then went over them again. A few moved just a little when I went over them but on the third round none of them moved. From the feel the better moly had a lot less friction. I'm really satisfied with the way they went in this time.

These are good looking studs, I didn't use the standard arps last set I had the valve covers leaked. These were set up to clear the valve covers and are set up for no bottom tap. I've always liked trying different stuff, you never know whats out there that's as good as a name brand product for half the price.
 
What brand are they and where did you get em from? I am up for trying something new for cheaper
 
These are higher than the standard arp's but are suppose to be the quality of the high dollar ones.index About 600 now a set. I like the way they are made, no bottom tapping and a short hex on top clears the valve covers. Probably close to price of standard arp's if you figure cutting down the rocker pedestal and the tap and time taping and clean up. Let me see how these hold up when I throw some boost at them.

I think the only problem I had was not using a good enough quality grease and not torqueing tight enough. They call for 105 ft. lbs. of torque but with the better lube had no grabbing at all. I'm going to call the guy next week and give him an update as to what I did. My thinking is he should supply the install lube so that quality stays the same.

If it pops a head gasket this time I will probably give up on these and go to the arp's.
 
Listen, dont listen to some of these guys that say buy name brand, bla.. Bla.. I just ran into a similar issue on a truck. Sold the customer the same studs and marine hg. They had the head cut. Blew the hg twice before bringing it to me. I pulled it apart, checked block. Looked good, speced out ok. Took head to my guys i always deal with. They said it was way to smoothe. They did a light recut to get the surface finish the way it should be. I put it all back together with the same studs. Max trq is 115. Do not go past. Did a few heat cycles and ran it hard, bout 42 psi. They couldnt get it over 30 without popping it before. Kept blowing out the front and back. So i bet u have a similar issue. Its notthe studs. These studs rock, i have them holding 80psi on my cr with the stock hg torqued to 125.. These studs do not stretch. Give me a call if u want. 989-280-9384
 
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