Retorque or not to Retorque ?

[Twil]

Just replaced my Head Gaskets and have driven about 10 miles. Should I (Do I have to) retorque the head bolts?? They are ARP head bolts and I torqued them to 85ft lb. I figured I need to retorque now that they have been heat cylced. The local GN mechanic says not to do it - he doesn't.

Any comments?

Brandon

 

[gofstbuick]

According to gnttype.org, ARP head bolts need to be retorqued after a couple of warm up cycles. I personally am using factory TTY head bolts, so maybe others will chime in.

 

[REDS HOT AIR]

50/50

nah more like 0/100 cause it cant hurt to retorque but could help so whats there to loose

 

[Nick Micale]

Don't know how many head gaskets [or type of gasket] your local GN guy has done? I did learn this the hard way by eating a few jobs and NOT re-torquing with ARP bolts. It is now ALWAYS done on any new motor or head replacement.

My procedure is to re-torque after 24 hours before starting the motor. Again after a couple heat cycles.

If you plan to never go over, 15 psi and never have detonation, this may not be necessary. It is a pain to drop the headers for a re-torque, but lots easier than replacing the head gaskets [or more!] again.

 

[Addicted2boost]

I retorqued mine as well. So far so good. I've had some knock too and held up.

 

[tcgn]

Addicted2,when you retorqued them.Were any bolts loose?

 

[qwknuf6]

retorque

Well I hate to say it but I dont retorque.(after running any way)
I do use GM gaskets and ARP studs
I do torque studs in proper order and let set for at least 1 hour .
I do ,after sitting , loosen each stud one at a time in proper order and torque back to proper torque spec.
I do all this while the engine is out of the car .
I have built 10-12 motors ,all raced ,and yet to blow a head gasket , some have knocked severly at the track .
The stock H/G is graphite and not as sensative to the heat as other gasket material , maybe this helps .
I think retorquing after running the engine is the best way but dont feel good about re torquing in the car .

 

[Louie L.]

I had a gasket failure which i believe was caused by loosing clamping force.I think thsi was caused because of failure to retorque as it occured on the area and fastener which i could no reach.

On my last build , I torqued and let it sit over night. Then like above loosened and retorqued in sequence. I have checked the torque several times and several heat cycless and have found no loss of torque or clamping.

I believe the above is a good preventative method to retorque while in the car.

 

[Intercooler]

Maybe with an aluminum head or steel shimms but not a composition gasket with iron heads. What does ARP say? If it doesn't say it in the instructions it is a coin toss.

 

[Nick Micale]

Originally posted by Intercooler
Maybe with an aluminum head or steel shimms but not a composition gasket with iron heads. ..........

Every alum head and/or steel shim gaskets I have found 1/8 to 1/4 turn more after a heat cycle. Stock type gaskets little after a heat cycle, but some after a 24 hour soak.

 

[KEVINS]

Just by looking at the above posts I don't see anybody posting that they blew a HG after retorquing but there are a few that did w/o retorquing... I think I'd retorque them..

ks

 

[JToups386]

ALWAYS, ALWAYS, ALWAYS Retorque your head gaskets!!!
I cannot stress it enough. While ARP bolts supposedly do not stretch, the heat generated still takes a toll on the fasteners, etc, and your only semi-guarantee to not prematurely blow a gasket, is to retorque them. I've learned this lesson the hard way, more than once. However, my last round of properly torquing and retorquing yeilded me a motor that still runs great and has no gasket leaks. Did I happen to mention,,, RETORQUE the head bolts...!?? Your local mechanic is payed on quick turnaround, and is only worried about getting it out the door in the least amount of time, rather than doing it the right way...
Hope this encourages you to make the effort, and prevent future gasket disaster. (also, always use ARP lube when originally torquing down)

 

[Intercooler]

GM doesn't suggest it and neither does ARP. They shouldn't move on you. If they did your initial install wasn't as up to par as you thought

 

[Intercooler]

Some info to go along with what I am saying. It depends more on gasket type. Why you would want a retorque type is beyond me. I only use Fel-Pro or stockers which don't need it. We don't know more than the manufacturers do we Grab a beer and have fun reading

http://www.federal-mogul.com/felpro...ngine_sealing/cylinder_head_gaskets/pg_4.html

http://www.arp-bolts.com/pages/products/pages/headstuds/links/headbolts.html

http://www.dreamwater.org/auto/mk3supra/Headgasket/blown head gasket files.htm

That click around to read it all. Should keep ya busy for a while

 

[qwknuf6]

BOLT STRECH

JTROUPS386 said:
While ARP bolts supposedly do not stretch


ARP bolts and studs do stretch , that tension is what actualy holds the torque .
Rod bolts, which are the most stressed part in the engine,should be installed with a stretch gauge for accuracy (per ARP)

 

[6PacktoGo]

Well, it's up to the individual I suppose. All I can tell you is that I usually average building 20-30 engines a year, and business keeps getting better, and I retorque the heads ALL high performance engines REGARDLESS of what fastener and gasket are used. It works, I can't remember the last time I lost a head gasket since I started retorqueing religiously.

There is one notable exception. We do have a 391 small block Chevy, on alcohol, with 11:1 compression and an 8-71 BDS blower. The throttle hung, and at about 8500 RPM, it was making in excess of 25 psi of boost. It blew the gaskets out from under the heads. Best I can tell it didn't blow until the last couple hundred RPM.

So that's a total of ONE pair of head gaskets in over ten years. I retorque with ARP studs and Fel Pro gaskets just as often as I do on claimers with stainless shim gaskets and stock bolts. Talk to most any professional race engine builder and he'll tell you he retorques heads his high performance engines. It DOES make a difference, don't let anyone kid you. Fel Pro is selling gaskets for street cars (stock ones) on the basis of not retorqueing . The Federal Mogul and Fel Pro tech reps told me I should retorque, so did ARP, and so did Smokey Yunick. Good enough for me, and it solved my problems.