[Deanfun]

*sorry the post is kind of long, but please read it, please!*

Well, I'm new to this forum, but i've been to the celicasupra site many times in the past - what a great resource.

In any case, it's taken a few months, but my buddy and I have finally settled on purchasing an '82 Supra L-type for our first rally car. Ignoring its practicality as a rally car and anything to do with what we're doing with the car, I have a few comments and questions.

To start, the engine is not stock. It's also not running, but that's besides the point. We can get it running via push-starting, so I'm willing to bet the starter is gone. However, what's under the hood when it finally does run is what's causing me some concern.

important things are bolded...

Without knowing specific specifics, the engine has been bored out to 3.0L (6m spec? I don't know, help please), the head has been ported and polished (how much power gain there?), the exhaust header is completely custom built (looks good, I believe it's a 6-3-1, but don't quote me), and there's a 2.5" (or maybe 3") straightpipe all the way to a very weird looking muffler (which i think has nothing inside of it). Also, it has a cone-filter intake thrown in for good measure.

From what I've read here, and at other websites (toysport, for one), I'm very confused. The person we're buying it off of stated that teh previous owner (the one who did the work) dyno'd the car at 200hp to the wheels; however, there is no sheets to prove this.

My question is: how much power do you really think this thing would pump out? I've seen some stats that say the 6M was a 3L, and that it had 190hp, but have also seen stats that say a 2.9 and 3.1 overbore on the 5M produce 220 and 240hp respectively. I'm just not sure what to believe.

In addition to this, service records for the car show that the car experiences "excessive valve clearance" and "blowby" causing oil-burning at high rpm. My questions on other forums have given me mixed reactions to this. The general consensus is that the blowby results from the engine not being properly broken in after being rebuilt 3 years ago (ie. the rings didn't get enough time to seat properly). The excessive valve clearance results from, we think, the fact that the head was planed, and thus the valves go deeper into the block when active.

So basically I'm asking for help in two areas: how much power am i making, and how severe are these problems that the engine has?

 

[LegendOPower]

I believe 200hp is a pretty high number, if you’re at 3.0 with high compression pistons (duno if that’s even possible with large valve clearance) it might be right (I’m defiantly not the expert)
Blowby sucks, but can be fixed with some work. The high valve clearance shouldn’t be much of an issue, but you don’t need an engine that is having a blowby issue that your going to be racing, you’ll turn the “some blowby” into “massive blowby” and have to fix it anyway pretty soon.
If it were up to me, and I had the funds and means to do it, I would look into getting a 6m, and doing a complete rebuild before you swap it in. that way you know exactly what is in that motor and know exactly how to fix it when you brake it


p.s. Good luck with the Rally Racing thing. I love watching it and im sure its fun as hell!

 

[Voyn238]

I'd believe 200 hp at the wheels, that sounds very much like my engine setup, and I dynoed at 225 ft lbs (got bad RPM readings so HP readout was screwed, but I believe it's somewhere in the 220 range). It's easy to check! Get the thing dynoed

Check the block stamping, and see what kind of engine it is. It's going to be somewhere near the AC compressor, I believe. Look for a flat spot with letters and numbers stamped on it. I'd bet it's a 6M. Boring a 5M out to 3.0L would be kind of hard to do, I think. I know it's been discussed a lot lately, but I'd still have to see it to believe it.

As for the parts, it's hard to say exactly how much HP is gained by each piece, but depending on the port work, you can expect up to 20 to 25 for the head (sheer guess) and anywhere from 15-20 from the exhaust manifold and 3" pipe. Say the cone filter is worth 5hp vs the stock airbox... So, if you've got a 6M engine, with a nicely ported head, and a well designed header, you'd be looking at about 240 at the block, which would turn into about 192 at the wheels. That's a rough guess, so don't everyone start nitpicking me here

The "excessive valve clearance" could be caused by one of two things. Either shaved head, or aftermarket cams. Either of those would add HP and I should think they would be considered favorable mods. If it's a shaved head, you should really get adjustable cam gears to correct for the difference in distance between the camshaft pulleys and the crank pulley. www.titanmotorsports has some *really* nice ones, and for fairly cheap. The other possibility is that you've got some aftermarket cams in there. You could take the cam covers off and measure the lobe height and base circle, and then compare these figures to stock cam specs. Either an increased lobe height or a reduced base circle means you've got aftermarket cams. Hopefully, if you've got them, they'll be the increased lobe height kind. The other type requires milling the cam towers to bring the cams closer to the head, and no one has had good results with these kind.

Any idea what the guy's name was that did the mods? He might be an ex-list member or something.


Oh, and if you need a starter, I have one off my old parts car, going cheap!


later

 

[Voyn238]

Oh, one other thing - if it's a 6M, the blowby could be caused by an incomplete or not-even-attempted rebuild. When I got my 6M, there was a bit of rust and water damage in the 3rd cylinder. I had the cylinders honed and the rings replaced. I'm not sure that even that took care of all the damage, as the car still goes through a good bit of oil.

Rebuilding it might be a good idea, and if it's a 6M with problems like mine had, you might have to bore the cylinders out instead of just honing. That'd give you a bit more displacement, and if you install '84 and up dome style pistons instead of the flat-tops, you will boost your compression into the 9.6:1 area... (I didn't do this last one myself, but I wish I had)



good luck, and let us know what you find out!

 

[Deanfun]

thanks for all the info guys - it's nice to find good forums like this.

Voyn238,
If no one else wants your starter and you still have it when we get the car, I may be in touch, thanks.

I won't be taking the car into ownership for another 2-3 weeks, so I can't just go poking around and stuff. I also just remember that the AC was removed from the car for weight-savings.

The current owner has records for all the work that was done to the car by the previous owner (well, most of them) so maybe i'll be able to figure out exactly what was done.

If it is a 6m, would it specifically say on the block that it was, or would it be some part of a serial number?

And one further question, for future reference: where does one go about obtaining a 6m.. are they one of those Japan-only-and-must-be-imported things, or were they in a different model toyota?

Again, thanks... expect me to be on here quite a bit more once I get the car. It's got a rather large rust issue in the rear passenger quarter panel that I'm going to have to deal with in some fashion. 8)

Thanks!

 

[Supraa_luva]

If you look just to the right of the oil filter you can see a number engraved on the block. It should say 5M #### or 6M #### designating which it is.

 

[Supraa_luva]

If it is And one further question, for future reference: where does one go about obtaining a 6m.. are they one of those Japan-only-and-must-be-imported things, or were they in a different model toyota?

oh, and both. lol. You can get them from those japanese engine importers. Easy to find. I found mine without even looking The guy I went to to have a 5m-ge put in actually suggested it to me before I even considered it being done. They are from the late 80's cressidas in Japan. Or so I've heard. The guy who installed mine said it came off an 88' cressida, but I've read somewhere on these boards they came off some other toyota.
Someone else know of it?

 

[Dave A.]

Look on the block in the area below the oil filter. The block ID stamping is on the flat surface just below the filter and should read either 5M or 6M. The 6MGE is a jap. spec. engine and can only be purchased from certain places like "Toysport" and a few others that import the used 6MGE engines from Japan. Does your engine have EFI or 3000 casted into the top of the intake plenum? All 6M's originally had 3000 on the plenum and no EGR valve. The block ID will let you know which actual block it is that you have. The 6M looks pretty much identical to the 5M externally, but the internals are different with a longer stroke crankshaft and shorter connecting rods. Let us know what you find stamped on the block and we can help you out with anything else that you need to know. 8)

 

[Dave A.]

Look on the block in the area below the oil filter. The block ID stamping is on the flat surface just below the filter and should read either 5M or 6M. The 6MGE is a jap. spec. engine and can only be purchased from certain places like "Toysport" and a few others that import the used 6MGE engines from Japan. Does your engine have EFI or 3000 casted into the top of the intake plenum? All 6M's originally had 3000 on the plenum and no EGR valve. The block ID will let you know which actual block it is that you have. The 6M looks pretty much identical to the 5M externally, but the internals are different with a longer stroke crankshaft and shorter connecting rods. Let us know what you find stamped on the block and we can help you out with anything else that you need to know. 8)

 

[Dave A.]

Hmmm, sorry for the double reply! I have no idea how that happened! :?

 

[Deanfun]

thanks again, I've got my friend going on saturday to nail out the deal.. he'll look for the serial number then. I've also asked him to take some pictures... the exhaust on this thing is... something else.