re-torque the head bolts?
Drifting
Joined: May 2002
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From: The Motor City
Re: re-torque the head bolts? (devilfish)
That is a good question. I'd like to know the answer to this one too. I've just bolted mine back on and I'm about ready to fire the car up for the first time.
I've read in the GM Performance Parts catalogue that their head gaskets do not need to be retorqued, but I don't know how true that really is and whether it applies to other manufactuers headgaskets (I used a set of Felpro 1010s)
I hope it doesn't have to be done 'cause it's gonna be a serious PITA job to do.
But does anybody know the answer to this question (Scorp, we're looking in your direction...)?
:lurk:
[Modified by TheCorvetteKid, 4:42 PM 5/12/2003]
I've read in the GM Performance Parts catalogue that their head gaskets do not need to be retorqued, but I don't know how true that really is and whether it applies to other manufactuers headgaskets (I used a set of Felpro 1010s)
I hope it doesn't have to be done 'cause it's gonna be a serious PITA job to do.
But does anybody know the answer to this question (Scorp, we're looking in your direction...)?
:lurk:
[Modified by TheCorvetteKid, 4:42 PM 5/12/2003]
Melting Slicks
Joined: Oct 2000
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From: Heidelberg PA
Cruise-In V Veteran
Re: re-torque the head bolts? (devilfish)
If you have AFR aluminum heads - Their website recommends retorqing after first cycle.
I am going thriugh this very situation where my head "walked-what AFR calls it, while the engineering technical name is"creep relaxation"", the heat differenc/expansion between aluminum and steel causes the head to float and lose the gasket.
I was on my last 50 miles of 1st 500 cruising at 60mph and I see in the mirrr - White Smoke. Pull over immediately checked out radiator, oil ect - no problems. Head home - no smoke for 15miles then a brief stint of smoke. I am currently besides myself since I am talking to Corkvette to see if I should just retorque or pull heads and replace head gasket.
After talking to AFR's tech they recommend retorqing at 250 miles. Generally you may not have to, but if they are AFR or aluminum, I would highly recommend retorqing to eliminate what I am going through.
Just found out that it looks like I will be replacing the head gaskets after only 475miles.:eek:
[Modified by 85vet, 7:34 PM 5/12/2003]
I am going thriugh this very situation where my head "walked-what AFR calls it, while the engineering technical name is"creep relaxation"", the heat differenc/expansion between aluminum and steel causes the head to float and lose the gasket.
I was on my last 50 miles of 1st 500 cruising at 60mph and I see in the mirrr - White Smoke. Pull over immediately checked out radiator, oil ect - no problems. Head home - no smoke for 15miles then a brief stint of smoke. I am currently besides myself since I am talking to Corkvette to see if I should just retorque or pull heads and replace head gasket.
After talking to AFR's tech they recommend retorqing at 250 miles. Generally you may not have to, but if they are AFR or aluminum, I would highly recommend retorqing to eliminate what I am going through.
Just found out that it looks like I will be replacing the head gaskets after only 475miles.:eek:
[Modified by 85vet, 7:34 PM 5/12/2003]
Drifting
Joined: May 2002
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From: The Motor City
Re: re-torque the head bolts? (85vet)
DUDE! :eek:
That TOTALLY bites it BIG TIME!!! I just finished doing my headgaskets. And while it's not an impossible task, it certainly isn't one I would wish on my worst of enemies! I definitely feel for you, and I'm sorry to hear about the luck.
I guess maybe I should consider retorquing my heads after the first heat cycle. I'm still a day or so away from actually firing my car back up. I'm running stock heads with the Felpro 1010 headgaskets. But I guess whether stock or aftermarket, aluminum heads can still experience creep relaxation.
It's just gonna be a SERIOUS PITA job to retorque the heads after the first or second heatcycle!
But thanks for the info 85vet. And good luck with the car.
That TOTALLY bites it BIG TIME!!! I just finished doing my headgaskets. And while it's not an impossible task, it certainly isn't one I would wish on my worst of enemies! I definitely feel for you, and I'm sorry to hear about the luck.
I guess maybe I should consider retorquing my heads after the first heat cycle. I'm still a day or so away from actually firing my car back up. I'm running stock heads with the Felpro 1010 headgaskets. But I guess whether stock or aftermarket, aluminum heads can still experience creep relaxation.
It's just gonna be a SERIOUS PITA job to retorque the heads after the first or second heatcycle!
But thanks for the info 85vet. And good luck with the car.
Melting Slicks
Joined: Oct 2000
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From: Heidelberg PA
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Re: re-torque the head bolts? (TheCorvetteKid)
Yeah - Crap does happen :mad
But, the best part is that I know the car will be a Stang killer when done.
PS - When you retorque you follow GM's procedure and loosen each bolt slightly then retorque. This is one H*** of a lesson to learn.
But I should be :auto: in a week or so.
But, the best part is that I know the car will be a Stang killer when done.
PS - When you retorque you follow GM's procedure and loosen each bolt slightly then retorque. This is one H*** of a lesson to learn.
But I should be :auto: in a week or so.
Safety Car
Joined: Jun 1999
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From: Austin, Singapore, Kuala Lumpur, Houston, Dallas, Hong Kong, Elgin, etc.. Texas
Re: re-torque the head bolts? (devilfish)
You must follow the instructions from the head bolt and gasket manufacturer.
One other thing. If you used TTY (Torque to Yield) head bolts, the correct installation procedure is to torque to relatively low foot/pound then turn the bolts so many degrees. The final torque reading is not used...it is the number of degrees.
The reason is TTY bolts need to stretch a little when properly installed. If they are over stretched, they loose most of their strength and will continue to stretch. Thus, TTY bolts should only be used once and thrown away.
My 1996 had the TTY bolts originally and I replaced them with the same from GM. I don't recommend using the TTY bolts as they are hard to correctly install using the Torque Angle Guage. If I had to do it again, I would use the ARP bolts and normal torque procedure.
There are a number of websites out there detailing the TTY bolts.
One other thing. If you used TTY (Torque to Yield) head bolts, the correct installation procedure is to torque to relatively low foot/pound then turn the bolts so many degrees. The final torque reading is not used...it is the number of degrees.
The reason is TTY bolts need to stretch a little when properly installed. If they are over stretched, they loose most of their strength and will continue to stretch. Thus, TTY bolts should only be used once and thrown away.
My 1996 had the TTY bolts originally and I replaced them with the same from GM. I don't recommend using the TTY bolts as they are hard to correctly install using the Torque Angle Guage. If I had to do it again, I would use the ARP bolts and normal torque procedure.
There are a number of websites out there detailing the TTY bolts.
Former Vendor
Joined: Jun 2001
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From: St Marys PA
Re: re-torque the head bolts? (devilfish)
I would not trust the stock head bolts, maybe that is some of the problems you guys are having?
I used ARP head bolts for the 350 and 406 and never had a problem with either. Never re-torqued or anything on either (knock on wood :smash: )
I used ARP head bolts for the 350 and 406 and never had a problem with either. Never re-torqued or anything on either (knock on wood :smash: )
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Drifting
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From: Little Rock Arkansas
Re: re-torque the head bolts? (ski_dwn_it)
ALWAYS retorque aluminum heads after a heat cycle... FelPro says their head gaskets (Perma-Torque) don't require it but that's B.S... Retorque aluminum heads!! It's a PITA but it's better than a head gasket leak!
-Jeb
-Jeb
Drifting
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From: The Motor City
Re: re-torque the head bolts? (jburnett)
I used the stock-replacement GM headbolts too. In fact, they came in a kit with Locktite already on the threads (although I put more on when I installed them). Funny though, these bolts are different from my original ones (smaller head with large flange underneath, and no washers). My machine shop said I didn't really need them, but I installed ARP hardened washers when I put the heads down anyway. They also said that the new GM bolts are actually very good.
I'll probably retorque my head bolts after the first couple of heat cycles. My intention is to let the car run through one heat cycle, then use STP engine flush which should take me through another one or two heat cycles. Once that's done, I'll drain the oil and replace with fresh Mobil 1. I'll run the car through one more heat cycle, THEN retorque the heads. I think that would be OK since the car won't be under any load at all (it'll be on jack-stands the whole time).
Does anybody see an issue with this sequence? Should I retorque sooner or later? I want to make sure I do this right. While I'm glad that I changed the head gaskets on my car myself, it's certainly NOT something I want to do again any time soon.
Thanks.
I'll probably retorque my head bolts after the first couple of heat cycles. My intention is to let the car run through one heat cycle, then use STP engine flush which should take me through another one or two heat cycles. Once that's done, I'll drain the oil and replace with fresh Mobil 1. I'll run the car through one more heat cycle, THEN retorque the heads. I think that would be OK since the car won't be under any load at all (it'll be on jack-stands the whole time).
Does anybody see an issue with this sequence? Should I retorque sooner or later? I want to make sure I do this right. While I'm glad that I changed the head gaskets on my car myself, it's certainly NOT something I want to do again any time soon.
Thanks.
Le Mans Master
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From: Sachse Texas
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Re: re-torque the head bolts? (TheCorvetteKid)
I have used both stock replacements and Felpro gaskets, ARP head bolts, and R&R'ed my heads many times. I always torque to spec the first time, and then fagettaboutit. Never had any problems with the head gaskets. I have also always used red locktite on th head bolts and retorqueing them would break the hold that the locktite provided unless you pulled the entire bolt out, cleaned the threads, and reinserted the bolt with fresh locktite. You would also have to drani the coolant to do this as well.
I'll stick to what I have been doing.
I'll stick to what I have been doing.
Melting Slicks
Joined: Oct 2000
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From: Heidelberg PA
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Re: re-torque the head bolts? (ski_dwn_it)
I would not trust the stock head bolts, maybe that is some of the problems you guys are having?
I used ARP head bolts for the 350 and 406 and never had a problem with either. Never re-torqued or anything on either (knock on wood :smash: )
I used ARP head bolts for the 350 and 406 and never had a problem with either. Never re-torqued or anything on either (knock on wood :smash: )
I used new ARP bolts as well. Looks like a cloud is following me.
Drifting
Joined: May 2002
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From: The Motor City
Re: re-torque the head bolts? (STL94LT1)
Weird. It seems like there are mixed reviews between ARP or stock GM head bolts, retorquing or non-retorquing, and even the use of red or white LocTite.
I'll personally retorque mine. I've got nothing to loose but a little more time and a little more energy. Besides, I've been working on the car for over 8 months - what's another half-day or so for retorquing my cylinder heads?
I'll personally retorque mine. I've got nothing to loose but a little more time and a little more energy. Besides, I've been working on the car for over 8 months - what's another half-day or so for retorquing my cylinder heads?
Race Director
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Re: re-torque the head bolts?
Never had to retorque the head bolts.Used fel pro 1010's on 2 different rebuilds and they only got torqued once before start up and went many thousands of miles and showed no problems.These were with aluminum heads and the stock GM bolts too.I cant see it hurting to retorque the head bolts if they need it though...if anything they may help for the piece of mind for the owner of the car.Just dont over torque and crush the gaskets too much in certain areas.That will lead to problems.
:)
:)
Le Mans Master
Joined: Oct 1999
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Re: re-torque the head bolts? (Bill's86Coupe)
I got 20K miles on my AFR 190 heads with new ARP head bolts then the rear of the fel pro head gasket began to leak down the side of the block.
I just got it running last weekend and I will be retorqing this time around. :yesnod:
I just got it running last weekend and I will be retorqing this time around. :yesnod:
Race Director
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From: Indianapolis IN
Re: re-torque the head bolts? (bill mcdonald)
I plan on re-torquing my DART heads after 1st heat cycle and used ARP bolts also. Primarily because the heads are aluminum and my gaskets are Copper, so its a must for me.
Drifting
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From: The Motor City
Re: re-torque the head bolts? (ld85)
It looks like regardless of what head bolts, sealant, and head gaskets are used, if you are bolting up NEW cylinder head castings (AFR, DART, stock, etc...) then they need to be retorqued; old or used cylinder heads, whether rebuilt or not, don't seem to need it. It makes sense when you think about it - old heads have already been heat cycled many many times over their lifetime, so the material has already flexed and crept. New castings haven't had the chance to do that.
Regardless, I will retorque mine. The heads I'm using are a used set of stock 113s that I bought from a Corvette salvage yard which I had rebuilt (I cracked one of my original heads when the car overheated on me last year). I don't think I'll have a problem if I don't retorque, but I'll do it for the peace of mind.
Regardless, I will retorque mine. The heads I'm using are a used set of stock 113s that I bought from a Corvette salvage yard which I had rebuilt (I cracked one of my original heads when the car overheated on me last year). I don't think I'll have a problem if I don't retorque, but I'll do it for the peace of mind.
