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· 2JZ NA-T
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7,624 Posts
Discussion Starter · #1 ·
hey guys, well fearing the worse , ( a blown hg) im starting to consider buying some studs and a hg if mine is indeed blown. this will be confirmed in a few days. Right now i have a 2.5 mm hg, which is a bit too thick for my liking. i think my compression is somehwere around 8.1:1, to low for a t61 turbo.

what would be a good thickness to go with while still safely droping the comp?

i was thinking maybe a 1.6 or 1.7 mm head gasket? wehre would i find it besides the HKS gaskets? those are too pricey.

i also considered stacking 2 gte gaskets....


and as far as the ARP studs, they are the same for the GTE and the GE blocks, correct?

how well do they hold up if i were to buy some used ones?
 

· 2JZ NA-T
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7,624 Posts
Discussion Starter · #5 ·
im going to do a compression test today to verify if the gasket is indeed blown, i really doubt it is b/c ive already made atleast 15 HARD pulls ever since i started suspecting it, and everything is still perfect, except engine getting a bit hot, but i think that might be my lean issue.

but if it is really blown i dont know if i should go with a factory gte gasket...or get an aftermarket 1.3,1.4, or 1.6 mm one... all i know is that im not keeping the 2.5, its killing my spool and i wont be seeing more than 21 or 22 psi any time soon anyways..
 

· 2JZ NA-T
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7,624 Posts
Discussion Starter · #6 ·
well, even after the comp test checked out :

150
140ish
140ish
142
141
150

im still told that it isnt a definate answer on wheter or not the HG is blown or not, i need to check for hydrocarbons in the radiator to see if it is leaking or not.


so wats the verdict, would a factory TT gasket do the trick? or should i upgrade to something a bit more thicker??
 

· Registered
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355 Posts
You said you have a T61 Turbo? Well, what I would do is run a Head Stud from ARP and get a Metal Gasket that is 1.2 Mil Thick. I know it's small but, the higher the compression the better the torque and horsepower even without the turbo. The Head Studs should prevent the BHG prob and anything else and run at small boost and work your way up. Too Thick of a gasket would make your ride a pig anyways. So, There's my opinion. BTW: Running High Compression, make sure to use higher octane 93 perferred. Peace!
 

· 2JZ NA-T
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7,624 Posts
Discussion Starter · #12 ·
eh.... if im goin to pull the motor and rebuild it, i would go with some aftermarket pistons and build a for-sure bullet proof block, i just want a head gasket a bit thicker then stock tt, anyone know the thickness of the factory gasket?
 

· Registered
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370 Posts
i remember when i talked to a guy at cometic a long time ago he said it was imperative that you machine the surfaces of both the head and the block to practically "glass smooth" (direct quote) before installing their hg, of course the differences in materials between theirs and a stock tt might play a role. He said that that this is the step most people overlook or simply don't do. I talked to my 2jz guru and he told me he ALWAYS sends the heads out to be machined and then simply takes a buffer wheel or something heavier to the block. Anyways, the point is that when doing this, you will be losing thickness in the head when it is machined, therefore requiring a thicker hg for the same overall gain in hg thickness that you were originally shooting for. just my 2cents, i don't know if this step is simply overkill or if it is wise to ensure that it is done properly.
 

· 2JZ NA-T
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7,624 Posts
Discussion Starter · #19 ·
i would never take a buffer or a polishin wheel to the block, not unless a machine shop is doing it, you can easily dig down too deep in one spot and not the another and then not have the gasket seal properly.

im runninga 2.5mm hg too know, and i probably will keep it that way unless i upgrade to a larger tubo which will spool slower w/out lower compression.
 

· Found E85 NOT in NJ!
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8,732 Posts
i would never take a buffer or a polishin wheel to the block, not unless a machine shop is doing it, you can easily dig down too deep in one spot and not the another and then not have the gasket seal properly.

im runninga 2.5mm hg too know, and i probably will keep it that way unless i upgrade to a larger tubo which will spool slower w/out lower compression.
Or just get a machinist's lapping block
 
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