Well, I found the limit for a stock head gasket.

[shaeff]

I'll bite.

Rational please!

i think he's implying that 100ft lbs is too tight for a stocker. i'll bet he thinks that since it's a composite gasket, that it squished and deformed from so much clamping pressure, which i suppose, could happen...

that coincides with the theory of re-torquing a stock HG. many believe that since it's old, it'll squish and actually be more likely to blow, but i re-torqued mine and had no problems.

why do you need to use brake spray on your metal head gasket?

coating it in permatex brake quiet makes a surface on the HG that is more prone to fill in small variations in the block surface. it's the same theory as using copper spray, but this wont melt and go into the water jackets. basically, the spray makes a better seal because it fills in any imperfections in the head and block deck.

people do it (i believe Adjuster is the pioneer in this) because they dont have the funds/time/energy to get the block properly surfaced. so basically they clean it really well with brake cleaner, a razor blade, and check it for trueness with a mechanic's straight edge, coat the gasket and torque it down. Adjuster has lots of luck with it, so others (such as myself and Grim, are jumping on the bandwagon!)

-shaeff

 

[Blue87T(Dan)]

Thanks

I always like to know the reasoning behind a statement when someone does not feel inclined to give their facts or opinions to back it up.

I am planning on doing a possible retorque (depending on what is found once my cam covers are removed) on my stock HG. I want to turn the boost up to 16-17 psi for a few runs at the strip. I was planning on around 70 or so torque wise.

Of course these (few) runs will be in Toronto, since I'm not smart enough to attempt to break my car around the house.

Dan




Dan

 

[lanternman]

^^^ I'll be right there with ya buddy. Maybe only 15psi for me, we'll see how my retorque holds up.

Grimjack,
I hope I take it as well as you, if I ever end up blowing mine. Good luck with the rebuild.

Brent

 

[Blue87T(Dan)]

^^^ I'll be right there with ya buddy. Maybe only 15psi for me, we'll see how my retorque holds up.

Grimjack,
I hope I take it as well as you, if I ever end up blowing mine. Good luck with the rebuild.

Brent

We are poster kids for going out of state and racing our cars. I wonder if they make a tow truck that can tow 2 MK3's at the same time back to MI.

Sorry for the Hijack.

 

[GrimJack]

We are poster kids for going out of state and racing our cars. I wonder if they make a tow truck that can tow 2 MK3's at the same time back to MI.

Sorry for the Hijack.

They do - most tilt decks can carry one on the deck at the same time as they tow one.

 

[IJ.]

Dan: At 100 ft/lbs I'd be a little concerned using an old maybe soft head and having it deform.
(All it takes is for a past owner to have overheated it a few times and it might be annealed, I couldn't find a second hand head that would pass the hardness test on the exhaust side so had to buy a new one)

 

[Blue87T(Dan)]

They do - most tilt decks can carry one on the deck at the same time as they tow one.

I call mine on the flatbed part then damn it.

Couldn't stay away from this one could you "One Jay" :icon_razz

 

[IJ.]

I call mine on the flatbed part then damn it.

Couldn't stay away from this one could you "One Jay" :icon_razz

ROFLMAO Dan!

 

[Adjuster]

I'm just spreading what I learned watching Tony in Las Vegas do a MHG on my car a few years ago. (At the SILV, my stocker finally went out on the way down there.)

I boosted 15 to 18 psi with this same bolt on turbo, stock HG, and stock bolts re-tourqed to 73lbs for many years. No problems, and on pump gas 93 or 91 octane. (Whatever I could find.)

The final capper for the stock HG was a few 20psi runs on the same gas, and a 100mph cruise to Vegas with no undertray in place. (My car was running hot the whole time. Also I was on the stock radiator, but had good coolant in there.) If I slowed down to about 85mph it cooled right back down, but at 100mph and 110mph, what the other cars in the pack were running, my car would heat up in 20 miles, and it did not help when the outside temp pushed up near 100f as we got closer to Vegas...

I've since worked on resolving the high speed overheating issues. Fluidyne radiator, larger full flow oil cooler, and used the stock oil cooler as the PS cooler. The undertray is back in place, and I'm happy to say the car does not overheat so far. (Have not run more than about 20 min at 100 to 110mph, but the needle did not move at all this time... )

One mod I'd like to get done before Vegas is reverse vents in the hood just aft of the radiator shroud to vent out as much hot air as possible. That and some better air flow mods to the front bumper/cover to allow more air up over the FMIC. I've also kicked around the idea of a larger, longer undercover/splitter to improve on the stock one for creating a low pressure area in the engine bay to draw in more air over the FMIC, Oil coolers and Condensor as well as the radiator.

Sorry about the hyjack, but I think most stock HG's failed due to the low stock bolt tourqe, missing undercovers, high speed hot weather running, and poor maintence regimens of many owners. (IE old coolant causing/allowing loss of metal in the head, and corrosion of all parts in the engine.) The excessive boost or detonation were just the final straw on the already overloaded camel.

 

[CTsupra]

Thanks

I always like to know the reasoning behind a statement when someone does not feel inclined to give their facts or opinions to back it up.

i didn't think i had to explain myself to the old members. i think it's pretty much common sense not to torque a composite hg that tight.

guess i should start going into more detail when i type.

 

[GrimJack]

Hmm... I'm afraid I have to disagree on that, Ct. I've always torqued my composite gaskets to near 100 foot pounds, it's been fine for years - until I started running too much boost.

 

[SupraMario]

i didn't think i had to explain myself to the old members. i think it's pretty much common sense not to torque a composite hg that tight.

guess i should start going into more detail when i type.

Amen to that. i have read enough BHG threads to make a novel.

 

[CTsupra]

Hmm... I'm afraid I have to disagree on that, Ct. I've always torqued my composite gaskets to near 100 foot pounds, it's been fine for years - until I started running too much boost.

maybe i should've been more clear with which hg. i just said i was going to try and be more clear, didn't i? :doh:

i was only refering to the hg's our cars originally came with.

...but for the sake of argument; have you torqued down a original toyota design hg to 100ftlbs, or are you going to prove me wrong and say that you're using the newly designed ones?

maybe the newly designed ones can withstand 100ftlbs, but i don't think an original one can since most have been abused and unchanged for the last decade or two.

 

[supra_stephe]

good to know about the brake spray. I'm still getting it all decked, but i might do that do so since the copper can melt.

 

[GrimJack]

Ah, I see. Sorry, I thought you were referring to composite gaskets in general, not the ones still on 15 year old cars from the factory.

Mine was a new version - I had to replace it when I blew a rod bearing late last year, plus the very first thing I did when I bought this car was tear off the head and replace the gasket. I didn't feel like trusting more boost to an old head gasket.

 

[Justin727]

bishop has pushed his 57 to 20-22psi many times on stock hg... damn sorry to hear the bastard blow tho. i know you'll get it fixed

 

[JerzeySlowpra]

you tihnk the bolts may have come loose? i go over my HG like every 5000 miles cause no matter what i do my exaust side bolts always come real loose, and i do 80 ft lbs. it probley was detonation or not enough fuel or the 100ft lbs like shaeff said was to much for the soft stocker

 

[MRSUPRA]

I beleive 20psi is too much for pump gas when your at stock compression, even on 94 octane. The summer heat probably caused that much more detonation which probably finished off your gasket. Good luck on the new headgasket job.

 

[Justin727]

24psi on 93oct.

 

[MRSUPRA]

Boom