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-   -   New to Supra's had a few Q's (http://www.toyota-supra.info/forums/mkiii-supra/18889-new-to-supras-had-a-few-qs.html)

turbot11 03-30-2011 04:29 PM

New to Supra's had a few Q's
 
Hi my name is Chris, I was wanting to learn a few things about an 87 Supra, and thought this forum would be a good place to find out. I've discovered that the best way to learn about a car is to talk to the people that have them. My gf's kid is looking at an 87 Supra turbo he wants to buy, according to the owner it supposedly only needs a headgasket. I am an enthusiest of the turbo Dodge cars of the 80's-90's Daytona's, Shadow's, Omni's etc.. I know alot about those but I dont know jack about the Supra's lol
I had a few questions about the car and engine. It is an 87 turbo inline 6, only mods listed are a 3.5" from turbo to cat, and a 3" cat back along with some Tien ss coilovers. How would I find out what series engine it has in it? Are the engines cast iron with aluminum head, or all cast iron? If aluminum is it common and necessary for the head to be planed? Do these motors use torque to yield head bolts? What headgasket would you guys recommend, something like a multi-layered steel, or would composite be ok? I'm going to have him look for signs of detonation, on a turbo Dodge a blown headgasket could be an indicator of too much boost, lean condition. Is there anything particular to this generation of Supra he'll need to check for before considering buying the car? Thanks in advance for any help/info you guys could offer :D

cre 03-30-2011 06:53 PM

Well, you've got me with the Daytona but I'll pass on most of the rest. ;)

This belongs in the MKIII section (1986.5 - 1992 (1993 in Japan) is the MKIII).

Unless it's been swapped (a good thing to find out) it will be a 7M series. This is the only series which came to North America and was the ONLY engine in the MKIII Supra until '89. Turbo models are the 7M-GTE and N/A are the 7M-GE. These are cast iron blocks with aluminum heads. They came with a composite HG from the factory which they are notorious for blowing... This is due to too low of a torque specification (Spec is only around 56ft lbs, should be around 75ft lbs for bolts and around 95ft lbs for studs). The fasteners are not TTY and may be reused if they pass a close inspection; I don't reuse 20yo fasteners but they should be fine if they're not pitted and haven't been torqued beyond their capacity.

The head should definitely be milled. If the block deck is flat and true and free of pitting or warpage you may use an OEM composite HG with little concern for it failing. For higher performance builds a MLS is a common choice, but for this you really have to get the block deck cut too; From the factory they just weren't smooth enough.

Detonation damage isn't terribly common... at least not in systems which are largely stock. But yeah, if you've got to take the head off, well, you're already there.

Other than the HG problem there's not much else that doesn't come with any 20+yo performance car which people like to buy just to beat the snot out of... ;)

Good luck to ya!

My88isGREAT 03-30-2011 08:18 PM

AHHH the good old Daytona, I love those cars.
Being the car is so old depending on how many miles it has, and what the original owners have done to it is very hard to tell what needs done if its not running. like CRE said the head is very bad about warping. If you rebuild it, the factory Toyota rebuild kit comes with a good composite head gasket (vs. asbestos original) good up to about 14psi I was told. Check the center support bearing on the drive shaft, if the drive shaft flops around that is a very expensive part, or you can swap out to aluminum drive shaft. Check for water in the back quarter panels through the plastic doors, or rust where the spare tire is. They are notorious for leaking. Osaka.com sells running japan domestic motors for cheap which could be a good way to, but you could rebuild the motor for less and know it is good. :-)

turbot11 03-30-2011 08:34 PM

Awesome! Thanks! Thats just the info I was looking for. Apparently it's an 85K car, if it's the headgasket then hopefully it would just be a matter or normal wear and tear and not cause someone beat it too badly, lol He's excited to have found a turbo Supra, but it wont be turned into a performance build, glad to know a composite can go on it so long as the deck is in good shape. Also I wanted to ask aren't these interference engines? Is there any special procedure for the timing belt? On the "Turbo-III" Chryslers the belt is so finnicky, a special tool is used to measure the hertz of the belt vibrating to properly tighten it. If he picks it up I might be assisiting him with the gasket, I dont want to jump in blind, lol Would you guys suggest the use of a head shim after the head is milled or would that be a bad idea? Thanks again for all the info I really appreciate it! :D

turbot11 03-30-2011 08:45 PM

Thanks! I'll have him check the driveshaft and spare tire well too. I love the Daytona's too, I have 2 lol, also an Omni GLH and Shelby CSX (Dodge Shadow) He's never had a turbo car so not pushing it past 14psi would probably be a good idea. the seller says that once the headgasket went it was parked and hasn't moved since. He's going to look at it tommorrow so hopefully I can get a better idea of what condition it really is in.
Thanks Again for the info!

My88isGREAT 03-30-2011 09:15 PM

Sounds great only 85k original miles. Don't forget to open the back plastic "doors" in the rear hatch and put your hand down in the rear quarter panels to check for any standing water. I had no problem like that with the timing belt. I completely rebuilt mine on my own with some help from my dad (a Mopar fanatic) . The timing belt uses the tensioner to set it, make sure you take a pic of the cam gears at top dead center so when you put it back together you will know it is the same. Once you put the belt on and release the timing belt tensioner, you turn the motor over by hand 2 times, then check that it is right with no loose spots, or the same tension on both sides. If you need parts http://www.sipracingmailorder.com/servlet/StoreFront is the bomb and Rich is a great guy. Hope it works out for you Chris! If you get the car PM me and I'll mail you a factory shop manual for it. I like when people take initiative to get these cars going. I know where one is that is just setting and the guy will not come off it, and I am too broke to flash some money at him to change his mind.

cre 03-31-2011 01:23 AM

The 7M never came with an asbestos HG. (It's argued that the torque spec was for an asbestos HG, but that's not likely either due to other design factors.)

Here's an online version of the Toyota Service & Repair Manual for the MKIII:

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/

It's for a '90 or '91, but the differences aren't too great.

EDIT: Oh, and I wouldn't go beyond 12psi or so really... 14psi and you're getting close to the peak efficiency of the CT-26 and on a hot day performance will suffer as may the hardware. Think of 14psi as the cap.

My88isGREAT 03-31-2011 01:58 AM

Cool, thanks for the link. Sorry thought it was asbestos, I was told the new ones you get OEM are way better (and could hold up possibly to 14psi) then what they come with 20 years ago though. The thing is everyone said "oh get a MLS head gasket" and its like "dude, I'm not even trying to boost it, just get it up to par so it will be reliable" I am running stock turbo on mine with no intention of changing it, just saying a composite is just as good for normal people. I have ass loads of power, cant wait to dyno.

turbot11 03-31-2011 02:07 AM

Thanks, I'll know tommorrow if he gets it or not! If so I'll definitely hit you up, the manual will help when the head goes back on :D Thanks again to all, everyone's been great and the info has been very helpful! I'll post back as to whether he gets it :D

cre 03-31-2011 05:25 AM

The problem really never was the head gasket; Yes, it has changed... the rings and jackets are all about 1mm beefier and I'm sure the materials have advanced as well.... But if you really think about it the average MKIII HG lasted 15+ years.

Sure, on a clean engine with a perfect deck and head the composite could take more than that. It's a matter of longevity though. Everything breaks, some things sooner than others. I wouldn't really go more than 12psi on a daily basis for the sake of the HG either. Whether it MIGHT hold up better than a lot of other people have experienced isn't something I like to bet my own engine on; I've been bit in the ass that way a few too many times in the past.

On a related note, when prepping for a composite head gasket you do not want a "smooth as glass" surface. Unlike the MLS HG the composite does better if it has the additional surface area and 'bite'.


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