purcashing 1987 toyota supra soon, YAY! HG questions inside.

[SideWinderGX]

k, just as the title says basically. before i say anything, i want to apologize if my main question has already been asked (it probably has), but i want to be as CLEAR AS POSSIBLE on this supra as i love skylines and supras, and want to take care of this for as long as possible.

saw it today, great shape, yadda yadda, rebuilt (or new, i forgot) engine with 100k miles on it, 7mgte engine with ct27 turbo (steel, not ceramic). the only thing worrying me is the head gasket problem.

my dad flipped out when i mentioned possibly bad headgaskets, because you have to rip the entire engine apart apparently. from what ive read, the block is iron and the head is aluminum, and electrolysis will slowly wear it away, the iron will degrade, etc. once i found out if the headgaskets are in good working condition or if they got replaced, ill go from there. but lets assume they ahvent. first, what should i buy to replace the problematic headgaskets? ive heard steel headgaskets and ARP studs, correct me if im wrong. secondly, how much will that ring up to? id rather not spend 2 or 3 grand on the car right off the bat, but if i need to ill put that into consideration.

thank you very much for any input, i appreciate it greatly! i should have the supra in my hands in 2 to 3 weeks

edit: the headgaskets, at this moment, are fine. the car runs immaculate. i just dont want a HG problem in the future, and would like to avoid the trouble.

[Kuban]

If you are going to do the replacement right away it wouldnt be a bad idea either way. No matter how many miles the engine has on it. If its a stock hg, and the head bolts were torqed to fsm standards it could blow under randomness situations. BUT if the head bolts were torqed a little above fsm standards, say around 80ftlbs than i wouldnt worry about it if your running stock boost with no mods. But if you plan on changing it out heres what i recommend.

ARP Head studs
105.00$
@
https://935motorsports.com/catalog/p...oducts_id=1022

Cometic 2mm Steel Multi-Layer
169.00$
@
https://935motorsports.com/catalog/p...roducts_id=767

That would be a good setup. Then of coarse new gaskets for the things you end up doing in the process (Intake, exhaust, turbo-manifold etc.).

Total part will probably run you around 350$ or so. IF your doing the job yourself. My good friend whos a mechanic said the standard time for the 7m by shop standards is rated at about 12 hours labor. Depending on the shops labor charges, could be as much as 1000$ in labor to as little as 700$.
All in all its not costing you more than 1500$ tops to get the headgasket redone with a hg that will sustain 30psi all day long.
Now say the hg is already blown. Then were talking about pulling the engine and sending the block and head out to a machine shop and get then resurfaced. Prices on that are grey area. Just hope its not already blown basically.

Good Luck!

*EDIT* The 7m is a I-6, not a v6 as alot of people commonly confuse it, thus there only being (1) headgasket.

[SideWinderGX]

Originally Posted by Kuban

If you are going to do the replacement right away it wouldnt be a bad idea either way. No matter how many miles the engine has on it. If its a stock hg, and the head bolts were torqed to fsm standards it could blow under randomness situations. BUT if the head bolts were torqed a little above fsm standards, say around 80ftlbs than i wouldnt worry about it if your running stock boost with no mods. But if you plan on changing it out heres what i recommend.

ARP Head studs
105.00$
@
https://935motorsports.com/catalog/p...oducts_id=1022

Cometic 2mm Steel Multi-Layer
169.00$
@
https://935motorsports.com/catalog/p...roducts_id=767

That would be a good setup. Then of coarse new gaskets for the things you end up doing in the process (Intake, exhaust, turbo-manifold etc.).

Total part will probably run you around 350$ or so. IF your doing the job yourself. My good friend whos a mechanic said the standard time for the 7m by shop standards is rated at about 12 hours labor. Depending on the shops labor charges, could be as much as 1000$ in labor to as little as 700$.
All in all its not costing you more than 1500$ tops to get the headgasket redone with a hg that will sustain 30psi all day long.
Now say the hg is already blown. Then were talking about pulling the engine and sending the block and head out to a machine shop and get then resurfaced. Prices on that are grey area. Just hope its not already blown basically.

Good Luck!

*EDIT* The 7m is a I-6, not a v6 as alot of people commonly confuse it, thus there only being (1) headgasket.

inline 6, yup. and 1500 is horrible for my wallet haha, ill have about 500 to spend by the time i get the car (about). id love to do it myself, but no room. our garage is packed and we have a slanted driveway, plus the weather is horrible.

so the only problem with the heads is that they werent torqued to a high enough level? or is there something else as well?

theres already some mods on it. the newer CT27 turbo, a CAI and a performance exhaust (not sure what size) is going on soon, since theres no muffler and hes just fixing the whole thing. ill have to drive it super careful and resist the urge to floor it :-X

[IHateHacks]

"Total part will probably run you around 350$"

Incorrect. That will cover the machine work on the head, the head gasket itself and head bolts. And yes, heads should always be sent to a machine shop regardless of what you think. You then need a turbo gasket set which you can only get at the dealer and is $95. You need intake manifold and intake chamber gaskets, fuel injector insulators, grommets and O-rings, copper sealing washers for the fuel rail, fuel line, and turbo oil feed, exhaust manifold gasket, EGR cooler and EGR valve gaskets, etc..... If you look at my BHG post I have a detailed list of all the parts that are needed to repair a head gasket and the prices. The price is more like $700 and thats with a stock head gasket. Metal head gaskets are easily $200 themselves. I paid $99+ shipping for ARP head bolts. Be prepared for extensive labor if you do it yourself, 20 year old gaskets don't just peel off. You better have the tools or a hook up for the tools or that bill will easily add up to $500 itself.

[SideWinderGX]

Originally Posted by IHateHacks

"Total part will probably run you around 350$"

Incorrect. That will cover the machine work on the head, the head gasket itself and head bolts. And yes, heads should always be sent to a machine shop regardless of what you think. You then need a turbo gasket set which you can only get at the dealer and is $95. You need intake manifold and intake chamber gaskets, fuel injector insulators, grommets and O-rings, copper sealing washers for the fuel rail, fuel line, and turbo oil feed, exhaust manifold gasket, EGR cooler and EGR valve gaskets, etc..... If you look at my BHG post I have a detailed list of all the parts that are needed to repair a head gasket and the prices. The price is more like $700 and thats with a stock head gasket. Metal head gaskets are easily $200 themselves. I paid $99+ shipping for ARP head bolts. Be prepared for extensive labor if you do it yourself, 20 year old gaskets don't just peel off. You better have the tools or a hook up for the tools or that bill will easily add up to $500 itself.

just finished up that topic, its 9 pages long, good information and now im scared. im having second thoughts about buying this car if THAT MUCH money and work is going to go into the damn thing. that looks like over 2 grand just to fix this stupid problem that toyota should have recalled.

im definitely not going to be able to do it myself, so im gonna have to send it into a mechanic that i know. ill have to specify ARP studs (better than bolts if i remember correctly?) and that special head that was in the second post of this topic.

this isnt looking good maybe my luck will hold and the guy had some head work done when the engine was fixed up 100k miles ago lol.

[Murd]

You don't need a metal head gasket if you're going to be running stock boost or slightly over stock. Just make sure it's torqued to 70-80ft/lbs. If you're not getting the block lapped you're probably better off NOT getting a metal head gasket as well... Both surfaces need to be extremely smooth to use a metal one. Get a stock head gasket kit from toyota, it should have all the parts you need in it, grommets and all. I'd suggest still taking the head to a machine shop however.

[SideWinderGX]

Originally Posted by Murd

You don't need a metal head gasket if you're going to be running stock boost or slightly over stock. Just make sure it's torqued to 70-80ft/lbs. If you're not getting the block lapped you're probably better off NOT getting a metal head gasket as well... Both surfaces need to be extremely smooth to use a metal one. Get a stock head gasket kit from toyota, it should have all the parts you need in it, grommets and all. I'd suggest still taking the head to a machine shop however.

what id love to do with the car is leave the turbo as it is, then slowly phase in some other parts....which i havent decided yet :-P or maybe i wont, ill just have fun with it and see how long i can keep her alive. either way, she isnt going above 300 HP unless i hit the lotto.

i just wanna fix this problem so i wont have to worry when im driving the supra...much like im worrying now haha. and if i get that stock head gasket kit from Toyota, that wont include ARP studs\bolts, correct?

whats the difference between studs and bolts, anyways?

thanks for all the info

[IHateHacks]

ARP head bolts vs. studs

On many street-driven vehicles, where master cylinders and other items protrude into the engine compartment, its probably necessary to use head bolts so that the cylinder heads can be removed with the engine in the car. For most applications, however, studs are recommended. Using studs will make it much easier to assemble an engine, with the cylinder head and gasket assured of proper alignment. Studs also provide more accurate and consistent torque loading. Heres why. When you use bolts to secure the head, the fastener is actually being twisted while its being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a relaxed modenever crank it in tightly using a jammed nut. The stud should be installed finger tight then, when applying torque to the nut, the stud will stretch only on the vertical axis.

Studs are much more difficult to install with the engine in the car, but are stronger and less prone to stretching. Head Bolts will be easier to install with the engine in the car, but are not reccomended for high-boost applications. On the 7MGTE engine, the most common source of headgasket failure is due to the factory head bolts stretching and failing, therefore, when replacing a headgasket, ARP hardware is a must.

[SideWinderGX]

Originally Posted by IHateHacks

ARP head bolts vs. studs

On many street-driven vehicles, where master cylinders and other items protrude into the engine compartment, its probably necessary to use head bolts so that the cylinder heads can be removed with the engine in the car. For most applications, however, studs are recommended. Using studs will make it much easier to assemble an engine, with the cylinder head and gasket assured of proper alignment. Studs also provide more accurate and consistent torque loading. Heres why. When you use bolts to secure the head, the fastener is actually being twisted while its being torqued to the proper reading. Accordingly, the bolt is reacting to two different forces simultaneously. A stud should be installed in a relaxed modenever crank it in tightly using a jammed nut. The stud should be installed finger tight then, when applying torque to the nut, the stud will stretch only on the vertical axis.

Studs are much more difficult to install with the engine in the car, but are stronger and less prone to stretching. Head Bolts will be easier to install with the engine in the car, but are not reccomended for high-boost applications. On the 7MGTE engine, the most common source of headgasket failure is due to the factory head bolts stretching and failing, therefore, when replacing a headgasket, ARP hardware is a must.

clear as crystal, thank you. now i just gotta worry about what is in the car already, and how much it would possibly cost to fix. i presume fixing it beforehand would be much cheaper than fixing an already blown headgasket

[Murd]

Originally Posted by SideWinderGX

what id love to do with the car is leave the turbo as it is, then slowly phase in some other parts....which i havent decided yet :-P or maybe i wont, ill just have fun with it and see how long i can keep her alive. either way, she isnt going above 300 HP unless i hit the lotto.

i just wanna fix this problem so i wont have to worry when im driving the supra...much like im worrying now haha. and if i get that stock head gasket kit from Toyota, that wont include ARP studs\bolts, correct?

whats the difference between studs and bolts, anyways?

thanks for all the info

Yes you'll have to replace the head bolts. As IHateHacks posted, ARP is the way to go when replacing them, wether you do head bolts again, or go with head studs. Head studs is the prefered item to put on your car for the stated reasons in his post.

If you DO decide to replace the head gasket after purchase, make sure you burp the coolant system properly after refilling. The "waterfall" sound will annoy the hell out of you if you don't. Look in the FAQ section here, there's a good write up on it, as well as how to reduce the problem in the future by modifying the thermostat.