Question about OE headgasket

[Sl1dewaysSupra]

So I got a complete engine gasket set, everything I need for a complete rebuild. The HG is the "revised" OEM HG from what I have been told, looks alot beefier than stock for sure. Just wondering what the max boost I could run on my NA-T and still be safe. My goal is 10-12psi, not right off the bat of course. Will this HG stand up to the task?

 

[1988SupraDreams]

Running 12 PSI all day long. No problems so far :bigthumb:

 

[Poodles]

it will hold... but you're already there, you might as well get the piece of mind of a metal headgasket...

 

[bowsercake]

With Arp head bolts/studs and no detonation you will be fine at that boost level. Are you going to use a SAFC or maftpro or some other piggyback?

 

[CRE]

Yeah, he's planning on going with the MAFT Pro.... one of these days. heh

If you don't use it Sl1deways, I will. I've got the feeling the wife's about to cut off all my Supra funding for some time.... :cry:

 

[starscream5000]

If 12 psi is all you think you'll ever want, then you should be fine with a composite HG with ARP hardware torqued to the correct specs per the sheets that come with them.

 

[jdub]

Make very sure you check the head/block deck for flatness per the TSRM. If you do decide to go with a MHG, there is an RA spec for smoothness that also has to be met...this is not required for a composite gasket.

Heed what what Chris said about ARP torque specs. The sheet he mentioned is specific concerning lube...that will drive the final torque. Do not exceed the specified torque.

 

[Sl1dewaysSupra]

^ I just ordered ARP head bolts last night. I'm pretty sure 12 is about the max I wan't as the car will also be my daily driver. But from what I hear once you get a little boost you just keep wanting LOL. I am sure that a MHG is in my future, but for now I need to get the car done so I can get back in school.

 

[starscream5000]

Just make sure the head and block are flat for the composite HG. You may want to considerd a copper spray for it also...

 

[billspreston01]

12psi 2 years 40,000 milesand 50+ passes down the 1/4mi no problems

 

[ViR2]

it will hold for sure, but it also will fail after some time. I would go MHG way just to be safe

 

[bountykilla0118]

it will hold for sure, but it also will fail after some time. I would go MHG way just to be safe

All things fail with time. Just prep it good and use arp stuff. I am using toyota bolts tq at 75lbs and i have been boosting 14psi for 2 years now and no issues. However if I was to do it all over again i would bought the arp stuff.

 

[Nomad707]

just torque it down extra, itll be fine.

 

[Rajunz]

Just make sure the head and block are flat for the composite HG. You may want to considerd a copper spray for it also...

I agree, I would use Copper spray and also I would not torque it down more than 70 ft. lbs using ARP Molley Lube. You can over torque those things and deform them before you ever start it. If you are using stock head bolts, try to get some ARP Molley Lube. Alot of shops that build race engines have tons of those tubes lying around. The ARP Molley Lube will give you a different torque reading than using motor oil on the threads. Also, get a thread chase or thread tap and clean all of your head bolt threads out using WD40. This is real important in order to get accurate thread readings. Follow the torque sequence in the TSRM and do it in 3-4 rounds.

 

[starscream5000]

^^ARP spec with moly lube is 80 ft/lbs on studs. What hardware are you speaking about when wanting to torque to 70 ft/lbs?

 

[jdub]

^^^ And it's 75 ft/lbs using ARP bolts w/ moly on an aluminum head.

 

[Rajunz]

I would not torque a composite gasket to 80ft/lbs.

 

[jdub]

Care to explain why? Or are you just pulling a number out of thin air?

If ARP hardware is used, the ARP torque specification should also be used. More than one HG job has had to be redone because ARP studs/bolts were not torqued properly...however, an over torque is worse than under torquing ARP hardware.

 

[dugums]

Care to explain why? Or are you just pulling a number out of thin air?

If ARP hardware is used, the ARP torque specification should also be used. More than one HG job has had to be redone because ARP studs/bolts were not torqued properly...however, an over torque is worse than under torquing ARP hardware.

I'm really interested in hearing thoughts on this. My head is going back on tomorrow. I am using a composite gasket and would like to hear what the risk is with torquing all the way to ARP spec. I have both ARP studs and bolts, so I was planning on using the studs.

 

[jdub]

Been beat to death...here's a little light reading for you:

http://www.arp-bolts.com/Tech/TechInstall.html

ARP is very specific about using their torque spec on their hardware...I highly suggest you ignore hearsay and follow the ARP spec sheet.