Torque once or retorque metal-base head gasket?

m38olddog · Post by **m38olddog** » Mon Jul 23, 2007 9:34 pm

I'm going to be installing a new head gasket in my M38A1 next weekend. I just picked up a Fel-Pro 7543-SBX from my local parts store, correct for the F-134 engine. The young fella behind the counter said that the metal-bottom head gaskets (like this one) don't need to be retorqued after the first warm-up. He said he thought all Fel-Pro head gaskets were of the single-torque type now. The sparse instructions with the gasket don't help. Have any of you used this gasket and, if so, does it still need to be retorqued after the first hour of running like the old ones? Thanks!

Post by **wesk** » Mon Jul 23, 2007 10:46 pm

If you go to their web site they claim that their MLS series Perma Torque head gaskets need no retorqueing.

http://www.federal-mogul.com/en/Afterma ... torqueMLS/

Torque Retention and Extra Support for Lightweight Designs

The preferred technology for many late-model vehicle engines is multi-layer steel (MLS). Recognizing that replacement applications typically offer less-than-ideal sealing conditions, Federal-Mogul engineers created an MLS technology that addresses the true aftermarket repair environment. The result is the Fel-Pro® line of PermaTorqueMLS products.

PermaTorqueMLS head gaskets offer a wide range of benefits, including:

* Strategically placed sealing beads that help eliminate leak paths
* Extra-strong stopper layers that provide superior primary combustion sealing (where applicable)
* Full-hard stainless steel material that maintains its shape despite thermal expansion and scrubbing between the block and head
* A unique, application-specific coating that enhances sealability

What’s more, Fel-Pro PermaTorqueMLS head gaskets provide the torque retention required to maintain positive contact pressure between head and block over the life of the repair.

MLS technology is specified on most current U.S., European and Asian engines in production.
_________________________________________________________
http://www.federal-mogul.com/en/Afterma ... rmatorque/

Sealing Solutions for No-Retorque Designs

Fel-Pro PermaTorque head gaskets are the professional’s choice for reliable, no-retorque type head gaskets. High-density materials and superior design specifically for the aftermarket repair environment demonstrate Fel-Pro’s commitment to providing sealing solutions that perform under pressure.

Fel-Pro PermaTorque head gaskets provide an ideal no-retorque design. These head gaskets compress enough at installation to conform to, and seal, minor surface imperfections while minimizing relaxation and maintaining adequate clamping force over long time periods.

Get the no-retorque head gasket that performs under pressure.
_____________________________________________________________
http://www.federal-mogul.com/en/Afterma ... atorqueSD/

The Premium Choice for Severe-Use Applications

Premium Fel-Pro PermaTorqueSD head gaskets are a superior choice for engines in severe-use situations, such as taxis, RVs and construction vehicles. Intended for non-multi-layer steel (MLS) applications, these ruggedly engineered head gaskets provide a variety of benefits, including:

* Increased armor thickness
* Stainless steel armor material
* Special flattening operation
* Enhanced body core thickness
* Printoseal® sealing beads
* Proprietary coating

Fel-Pro PermaTorqueSD gaskets are a superior sealing solution for hardworking engines.

m38olddog · Post by **m38olddog** » Tue Jul 24, 2007 12:47 am

Thanks for the fast and detailed reply Wes ! Yes, I did go to the Fel-Pro website and saw that they make several types of no-retorque head gaskets. I would have expected the packaging and/or the instructions to mention this, but this 7543-SBX gasket is not marked MLS or Perma-Torque, so I was wondering if all Fel-Pros were now of this type. I'd hate to be skipping the re-torque if it is needed... or to be re-torqueing when it wasn't. I appreciate your taking the time to provide so much info !

Post by **wesk** » Tue Jul 24, 2007 7:48 am

Dave,
If your package or the gasket was marked as "Perma Torque", or "PermaTorqueMLS" or "PermaTorqueSD" then you do not need to retorgue the head. If it does not carry one of the three trade markings listed and it is from Felpro then it's a standard old style gasket and must be retorqued. I also noticed the online catalog requires the use of "BOLT PREP GRA2 REQD" with that gasket part number.

m38olddog · Post by **m38olddog** » Tue Jul 24, 2007 9:09 am

Thanks for the follow-up Wes. I'll be re-torqueing, and using thread sealer too. As always, I appreciate your help.