Re: Retorquing head bolts after initial fire up: myth?
[Re: domingo]
#1446228
06/02/13 11:37 AM
06/02/13 11:37 AM
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Joined: Jun 2003
Posts: 52,972 Romeo MI
MR_P_BODY
Master
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Master
Joined: Jun 2003
Posts: 52,972
Romeo MI
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I've never re-torqued the heads... I do the 3 step torque process and call it good.... but maybe thats why I dont ever make any big power... but the head gaskets never show any leak EDIT I do check them the next morning if I didnt finish up the top end... but never seen it change
Last edited by MR_P_BODY; 06/02/13 11:39 AM.
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Re: Retorquing head bolts after initial fire up: myth?
[Re: Thumperdart]
#1446230
06/02/13 12:08 PM
06/02/13 12:08 PM
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Joined: Feb 2005
Posts: 20,190 PA.
pittsburghracer
"Little"John
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"Little"John
Joined: Feb 2005
Posts: 20,190
PA.
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I have never ever retorqued a head gasket in my life. But then again I spray every head gasket I put on with High-tac sealer.
1970 Duster Edelbrock headed 408 5.984@112.52 422 Indy headed small block 5.982@112.56 mph 9.42@138.27
Livin and lovin life one day at a time
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Re: Retorquing head bolts after initial fire up: myth?
[Re: pittsburghracer]
#1446231
06/02/13 09:29 PM
06/02/13 09:29 PM
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Joined: Jan 2004
Posts: 13,247 Mt. Vernon, Ohio
dartman366
I Live Here
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I Live Here
Joined: Jan 2004
Posts: 13,247
Mt. Vernon, Ohio
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Quote:
I have never ever retorqued a head gasket in my life. But then again I spray every head gasket I put on with High-tac sealer.
I run Cometics sprayed with Permatex spray copper and have never had an issue of not re-torquing,,,come to think of it I have never had issues with Fel-pro perma torques eather.
Light travels faster than the speed of sound,,,this is why some people seem bright untill you hear them speak.
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Re: Retorquing head bolts after initial fire up: myth?
[Re: domingo]
#1446233
06/03/13 06:00 AM
06/03/13 06:00 AM
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Joined: Jan 2003
Posts: 8,941 Holly/MI
Dean_Kuzluzski
master
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master
Joined: Jan 2003
Posts: 8,941
Holly/MI
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I retorqued the headbolts on a generic 327 SBC motor way back in the day. Don't think I actually made it through the whole set. It was pretty obvious that the elasticaty/stretch of the headbolts were holding torque very well
Aluminum heads tend to expand more and may need it. I'll check that once I put mine together.
I always recheck intake manifold bolts periodically since I have found them to be loosened up on many used vehicles I've bought. They have a lower torque value to begin with.
R.I.P.- Gary "Coop" Davis 02/09/68-05/13/04
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Re: Retorquing head bolts after initial fire up: myth?
[Re: Mr.Yuck]
#1446235
06/03/13 02:20 PM
06/03/13 02:20 PM
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Joined: Jan 2003
Posts: 2,931 A shed in England
Tig
master
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master
Joined: Jan 2003
Posts: 2,931
A shed in England
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Never used to do it on all iron motors. We had issues with the fire rings distorting and burnishing the head on the 572 motor, we now re-torque the heads and we don't have the problem. They do seem to loosen off after the initial fire up and cool down. All alloy motor. EDIT: Fel-Pro instructions tell you to re-torque for racing applications BTW
Last edited by Tig; 06/03/13 02:22 PM.
'74 Challenger..9.46 @ 145.9 1/4, 6.001 @ 118 1/8 so far. 4023lb !!! # N/A, Marsh performance 655ci, Indy Maxx, T/R, Indy 600-13 X's, Street legal, pump gas, full interior, Cal-Tracs, mufflers, 3:73's and real 10.5 radials. 9.51 @ 142.4 1/4, 6.003 @ 114 1/8 with our old mule KB, 572-13, 580 wedge. RHD '68 Barracuda Fastback 323ci street/strip. Best ET 13.88 @ 99.03
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Re: Retorquing head bolts after initial fire up: myth?
[Re: Tig]
#1446236
06/03/13 03:22 PM
06/03/13 03:22 PM
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Joined: Nov 2009
Posts: 3,410 Belpre,Ohio
CHAPPER
master
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master
Joined: Nov 2009
Posts: 3,410
Belpre,Ohio
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I usually do a re-torque after engine has been brought up to operating temp, then coolant drained, and allowed to cool overnight. This is on an engine that I have had on the test stand and have the time to do it. If I do work where the motor is not ran here, I do not go find it and re-torque.
If you like drag racing, support your local track.
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Re: Retorquing head bolts after initial fire up: myth?
[Re: Performance Only]
#1446238
06/03/13 08:59 PM
06/03/13 08:59 PM
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Joined: Jan 2003
Posts: 9,670 Lima, Peru
domingo
OP
EL Master
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OP
EL Master
Joined: Jan 2003
Posts: 9,670
Lima, Peru
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Dan,
The cold re torque method doesnt say this is done after haven broken in the engine, but 1 hour after the initial torquing of the head to the block? So this is part of the assembly process even before firing it up fot the first time?
I guess what CHAPPER is saying is that he does the same procedure of retorquing the bolts, but he also backs up them some before retorquing (thats why he says he drains the engine of all fluids first) and then torques again to spec? Hey Chapper, did I get it right?
I am asking because when I have seen people doing the retorque, they go and just set their torqmeters to the desired rating, and then they just torque them without draining fluids and loosening the head bolts some....which I would think is wrong since maybe the torque reading might only (or partly) be from just twisting the bolt heads, instead of further stretching the fasteners to the deisred spec.
Last edited by domingo; 06/03/13 09:00 PM.
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Re: Retorquing head bolts after initial fire up: myth?
[Re: domingo]
#1446240
06/04/13 03:17 AM
06/04/13 03:17 AM
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Joined: Oct 2006
Posts: 427 Sweden
Mopar Guy
mopar
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mopar
Joined: Oct 2006
Posts: 427
Sweden
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Quote:
Dan,
The cold re torque method doesnt say this is done after haven broken in the engine, but 1 hour after the initial torquing of the head to the block? So this is part of the assembly process even before firing it up fot the first time?
I guess what CHAPPER is saying is that he does the same procedure of retorquing the bolts, but he also backs up them some before retorquing (thats why he says he drains the engine of all fluids first) and then torques again to spec? Hey Chapper, did I get it right?
I am asking because when I have seen people doing the retorque, they go and just set their torqmeters to the desired rating, and then they just torque them without draining fluids and loosening the head bolts some....which I would think is wrong since maybe the torque reading might only (or partly) be from just twisting the bolt heads, instead of further stretching the fasteners to the deisred spec.
I use the 3 step version on Cometic on my engines and wait for about 20 min and then i loosen and retorque one bolt at a time in cross pattern ! Works good on a 11,5:1 RB stroker whit no issues
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