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It's only the beginning..
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Doing HG Job, Wondering if I should use a silicone sealant on to bond the gasket, or if I should use something else... or if I should use nothing at all?
 

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no, i wouldn't use a silicone sealant
it will probably just burn off.
Most people spray it down with some copper spray or other sprays to make the gasket a little sticky.

Are you replacing it with a stock headgasket or metal?
if stock i wouldn't bother spraying it.
 

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i just got done doing my mhg. i used the 3m 77 adhesive spray, been driving my car for over a week now with no problems. when i researched it i primarily checked SOGI and here. I've heard of the copper and silver sprays being used without a problem, the same for the 3m spray.
 

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Permatex Brake Quiet
Adjuster said:
Yep, I've used the brake quiet spray on a few HG's for the 7MGTE. (Mine, and two others, plus a few guys here on the boards have done it with good results too.)

I was told about it by Tony, the guy with the Orange MK3 making 800+rwhp in Vegas. (He did a MHG change for me at a SILV one year, and this was one of a few good tips he gave me.)

The brake quiet spray is nice and tacky, seals up the gasket really well, and is very heat resistant. (Burns off around the cyc edge I'm sure, but not anywhere else.)
I've seen heads pulled off later after using the brake quiet, and it is still intact, sealing up the coolant and oil passeges nicely.

I don't know the Cometic gasket, but I've used a Greddy gasket on 4 motors now. (Same gasket, no failures, but the engines went down for other reasons. #4 is running strong however.)

Here is the easy way to use this stuff.
Clean everything very well with brake cleaner and some rags. (No oil is best.)
Then hang the gasket so you can spray both sides. I use a bungie cord off the track for my garage door.
Spray both sides of the gasket, putting a nice coat with minimal runs. (They are no big deal if you do get a run, but you want a nice thick coating, so two coatings per side is a good idea.)
Let this hang for 10 to 15 min and get nice and tacky. (Dry out some.)

Make sure you do not have head studs in place yet. I've found putting the head into place with studs on is a total PITA, and you have to back out the studs to get the washers into place anyway.

Now, you have cleaned up the block with brake cleaner and clean rags. There is no oil on the block. (or any other debris.)

BEFORE you lay down the gasket, put two small beads of "The Right Stuff" sealer (or other sealant) at the point where the front cover it attached to the block. IF you don't seal this up with sealer, it will leak oil later. (Or if you did not machine the block with the cover in place, it will be too high, and you will need to file down the front cover to the height of the block deck.)

Make sure you have the right side of the gasket, and lay it down on the block in place. (Only fits one way, but if you try and put it on upside down, it will screw up the brake quiet coating, and you will have to clean it all up, and coat the gasket again.)

Get a friend to help place the head onto the block. (Or do it yourself, I've had no issues on a few engines this way.)
Do not lay the head down, and then slid it into place. It needs to drop onto the alignment studs/dowels with very little if any sideways movement once you contact the metal head gasket. (You don't want to mess up the brake quiet.)

Use the moly lube on each stud, and the washers. I've found that sliding the washers down the studs is the easy way to drop them into the right place on the head. Make sure you have the Allen head up on the stud. Then put the stud into place finger tight. (Do no tourqe it down.) Do this for all the studs/washers. Then lube the nuts, and put them into place, also finger tight. (I used a 12 point deep socket to help after getting the nuts started to make sure nothing was cross threaded.)

Start your tourqe passes. I go to 50lbs first. Then 70, 90 and finally end up at 100 ish. (Current ones are at 103lbs.) Follow the TSRM pattern, going from the center, working to the outsides in a cross pattern.

You MUST tourqe down the head when you place it onto the engine before the brake quiet fully sets up. (I'd say you have about 45 min or so after you spray the stuff on. Really more like 30 min if you let it get tacky for 15...)

Good luck, and enjoy the power and fail free operation of a good MHG.
 

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It's only the beginning..
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Discussion Starter #5
Thanks :D
 

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Digital Dreamer
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I used Permatex myself, seemed like the cool thing to do. BTW as soon as I read the part about using 3M super 77 adhesive spray I laughed. I used to use that crap for applying vinyl to my interior pieces, but it wouldn't stick well as the sun would melt it! I switched to 3M 90 which was better, and didn't melt as fast, but still didn't last more than a couple months.
eric
 

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Now with less BHG...
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gee, wonder how it'd hold up to the temps on-engine huh, hahaha
 

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92 TURBO
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1988SupraDreams said:
Doing HG Job, Wondering if I should use a silicone sealant on to bond the gasket, or if I should use something else... or if I should use nothing at all?
NOTHING on the stock Toyota HG and NOTHING on a Cometic MLS according to the factory when I called them. Clean the block and head with lacquer thinner or brake cleaner just before installing HG according to the Cometic fact. rep. and torque in sequence to 75 - 80 ft/lbs using ARP bolts in 3 to 4 passes using a good click type torque wrench. I did 20- 40- 60 -75 using ARP's moly lube.
 

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What about belt conditioner spray???, it dries sticky, its all i have laying around and i need to install my head gasket right NOW
 

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well im using a fel pro gasket not mhg, thanks though, screw it im just gonna spay this stuff on it
 

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Permatex Copper Spray.
 

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mhg shouldn't require any sealant, unless you cut it out of a soda can yourself.
 

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92 TURBO
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NOTHING on the stock Toyota HG and NOTHING on a Cometic MLS according to the factory when I called them. Clean the block and head with lacquer thinner or brake cleaner just before installing HG according to the Cometic fact. rep. and torque in sequence to 75 - 80 ft/lbs using ARP bolts in 3 to 4 passes using a good click type torque wrench. I did 20- 40- 60 -75 using ARP's moly lube.

^ It's been 3+ years & 22K miles later, NO PROBLEMS with my engine rebuild which I did all myself except for the block & head machining. All Toyota parts, rod & main bearings, all hoses & complete gasket set except for a new .065" or about a1.6mm Cometic MLS HG to make up what was milled off the block & the head to keep the stock compression ratio and the correct TB crank to cams distance height. No spray used as per Cometic factory rep.

Mike
 
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