New MK3 Supra owner. 7mgte Build. Need Help.

[MK3LVIN]

I just bought my first 1989 MkIII Supra earlier this year and it's an NA. It's a 5 speed (W58) with a stock LSD Differential.

Currently, my 7MGE runs but it blows white smoke on a cold start. I don't wanna mess with it but any kind of info about fixing the white smoke would be good...? :icon_bigg

My future plans on this car is to swap a 7MGTE engine on it and it would be my VERY FIRST BUILD.

I bought a complete motor (Block, head, wire harness, injectors, intake and turbo manifold and some other parts) but previous owner told me it had a rod knock when he pulled it out of his 88 MkIII.

I recently dismantled the motor and found the connecting rod (cylinder #5) had some kind of metal wear/scratches where it is connected on the crankshaft (even the bearings and the crankshaft have some scratches).

Would it be best if I'll just change the Rods and pistons with new oversized one's...? (Including new bearings).

As far as the crankshaft goes. Can anybody tell me what I should look into or do with the crank that I have right now...? Info about good condition crank and bad condition crank?

Parts that I need:
Air Flow sensor
Intake Manifold
Turbo
Intercooler piping kit
Transmission...? would the W58 go well with the GTE Motor?

I am sure I'm missing a lot of things to make this motor come to life again. Can somebody help with the list? Big and small stuffs.

Parts that I have:
M/T 7MGTE ECU
WIRING HARNESS
TURBO MANIFOLD

This is my First ever build and I really wanna do well on it. (Got to spend money wisely). :biglaugh:

Thanks in advance.

:icon_razz

 

[AbsoluteSpeed]

First off, welcome to the site!

White smoke means burning coolant and likely means a bad head gasket (BHG). Unfortunately a BHG is all too common with the 7M motor and will be fatal.
So you may be swapping motors sooner then you planned.

One key question that has to be asked is; what are your power goals with the motor?
This will help answer your questions about upgrading pistons/rods and if the transmission will hold.

 

[MK3LVIN]

Thanks for the Welcome!

Thanks for the info about the white smoke. Hope it won't get worse and break down on me before I finish this build.

Well for this build I don't wanna go crazy on HP, I just want it to kick more compared to the stock GE.

I would say 450-550hp would be my goal for this first build.

 

[ForcedTorque]

Welcome!

I wouldn't be so quick to diagnose it with BHG without some hard evidence to support it. I'm not smart enough to give you any other diagnosis, but others may be. Is it a constant white smoke, or just an occasional cold start thing? Sweet smelling?

There's 3 things that point towards BHG though:
1. It's a 7M - It's know for BHG because of having a cast block and aluminum head, paired with a factory torque spec that is too low.
2. You just bought it - There once was a thread around here about how many people bought their first Supra with BHG unsuspectingly.
3. You have a little smoke - There could be any number of reasons why.

Are you having to add coolant? Ever? Is there any sign of oil in your coolant? Look into the radiator. Pull your oil filler cap and turn it over. Is ther a chocolate milky looking substance in there? Do a compression test. That will tell you for sure.

Now, for your transmission question. It is said that the W-58 is OK at stock 7mgte power level, and possibly up to 300hp. After that, you will want to upgrade to the R-154.

 

[AbsoluteSpeed]

^Good point, I hate when people are to quick to say "you have a BHG". I wasn’t saying it was a sure thing just a possibility.

I would say 450-550hp would be my goal for this first build.

You will need to make a few upgrades so your motor will put up with this.
Metal Head Gasket and ARP studs - This will prevent a HG leak in the future but both the block and head must be machined to ensure a flat surface.
Rods- you could use stock rods, have them shot peened and use ARP bolts (this would probably be safe to ~500) or get a aftermarket H-beam rods.
Pistons- you could use stock or forged, it's up to you.

A few other things you will need:
-larger injectors
-Better fuel pump
-3" exhaust
-Boost controller
-Wideband AFR gauge

You’ll also have to figure out a way of tuning the car and choose a new turbo as stock will not cut it. (you can look at stock turbo that has been upgraded like this http://store.driftmotion.com/static/i-57trimct26turbo.php)
A lot of people will use a Lexus air flow meter (AFM) with 550 injectors and a walbro fuel pump.
This will only net you ~350hp but is a great start

 

[MK3LVIN]

ForcedTorque:

The white smoke is every cold start. It doesn't only happen on mornings even in the afternoon if I let the car sit for a couple of hours.

I'll do a compression test soon though in order to further diagnose the problem. And I haven't added any coolant to my reserve tank since I replaced the radiator with a new one.

R-154 should be a good way to go with my HP goals in this build. (Just to make sure it will keep up with the motor). I'll keep an eye out for a good condition R-154.

AbsoluteSpeed:

A lot of good info there. Thanks.

I'm bringing my block to my friends shop this friday and he can look at it (including the crank, the pistons). I'll bring it to the machine shop as soon as I know my block and crank are in good shape for this build.

Wideband AFR Gauge? More research for me.

Right now i'm more focused on the block, head and all internals to make sure. Any ideas for a good turbo?

Will the stock 7mgte AFM work??


Thanks again for all the replies and info about this thread. Really appreciate the help.

 

[ForcedTorque]

For your stated goals, the metal head gasket (MHG) is very good advise. Do not miss the advise on getting both head and block machined to certain RA specs in preparation for the MHG. You'll need to research the proper specs as I don't know them right off. And, be sure that your machine shop is aware of this and capable. You need better than a standard GM 350 needs. If not done right, you won't get the benefit and dependability of spending that money.

You can use the stock 7MGTE AFM for a while at lower HP levels. It will only get you to about 10-12lbs of boost before fuel cut though. After that, you will want to either do the LEX/550 mod, or MAFTpro is the newer alternative.

BTW..If you decide on the lex/550 route, I have 3 Lexus AFM's to sell at $45 shipped each. That is without electronics though.