1984 Supra Rebuild

I picked up an '84 Supra last spring for $500 with what I believed was just a blown head gasket .Turns out the engine threw a rod through the side of the block and I had to source a new engine. I found this engine locally for cheap and this being my first real project I'm now unsure of how to proceed. Can I just reseal this or does it need to go to a machine shop?

Here are some images of the piston bores. I believe the pistons are already .030" oversized based on the stamping on the piston face, but I haven't actually measured.

I also pulled a couple of crank bearings and rod bearings. Are the grooves in the bearings a concern? They aren't really deep, but I can catch a fingernail on it.

I didn't check all the bearings, but of the ones that I did they all showed some grooving to varying degrees with the worst pictured above.

I've been reading the forum for a few years now, but I've only just now created an accountant to post. I really appreciate the community and knowledge on this forum and hope to contribute to it in the future and I appreciate any feedback.

And because I know it will likely asked soon, here are some photos of the Supra when I picked it up last spring.

Silver color my car kryptonite.  Good find.  

Nice looking car!

I need one of these one day. Nice car. Is it lowered?

yupididit said:

I need one of these one day. Nice car. Is it lowered?

Thanks! It’s definitely lowered, but I’m not sure how much over stock.

Cool project. Definitely an under-appreciated platform IMHO

I'd change all those bearings, if you take them out and there's any question, you might as well put in new ones. Anything deep enough to catch your fingernail on is too deep for a hydraulic bearing surface. The cylinders don't look bad from the pics, one has what looks like hone marks, if you can't feel them don't worry about them. Is there any specific damage you see on the cylinders?

love me some good mk2 supra's. They are getting hard to find in a decent condition anymore.

GameboyRMH said:

I'd change all those bearings, if you take them out and there's any question, you might as well put in new ones. Anything deep enough to catch your fingernail on is too deep for a hydraulic bearing surface. The cylinders don't look bad from the pics, one has what looks like hone marks, if you can't feel them don't worry about them. Is there any specific damage you see on the cylinders?

That’s what I was assuming on the bearings. The main thing on the cylinders is the band of buildup on the top. I can catch my fingernail on it a little bit, but I haven’t really tried cleaning it up either. Or maybe it isn’t a big deal since it is above the top piston ring?

I would definitely change them.  Anytime I see wear on one I change it if they are out.  You've gone this far, and the price shouldn't be that bad, I'd change them regardless.  Be sure and check the crank too if you haven't already.

I agree that these are underrated.  They were always a good looking car, and when they came out, they kinda shocked everyone with width of their tires.  Japanese cars were not known for that it definitely was a new thing.

Nice! A fellow “a65” chassis owner! Hey, if you are going through all the work of rebuilding a bottom end, just buy a 6mge (or find an NA 7mge here in the States, but good luck with that!) the 6mge were JdM yo! Only, but they were 200hp out the door. Which is plenty for that chassis. Or just 1uzfe swap it. http://www.celicasupra.com/forums/showthread.php?56444-Mike-s-(Supersubs-s)-Big-Boy-Build#/topics/56444

In for a penny in for a pound...

The stuff that made those scratches...where is it now? Gone or waiting in the oil galleries?

By cracking the engine, you are in a situation where you need to have it as clean as possible for reassembly. I would tear the whole thing down and pay a machinist to go over the critical measurements. They can return a clean, honed ready to assemble block for you to start building up with confidence.

I will toss in a tid-bit that I never learned until after I had assembled a few engines: When putting the main and rod bearings in, you want the friction faces to be covered in assembly lube. You don't want any assembly lube or oil on the backsides of the bearings as it will alter clearances. Obvious I know, but only after you see it.

Pete

Sorry you've ended up so far into the engine when you were only planning a head gasket. But that is one seriously good looking car for $500. As in I feel like you got a heck of a deal on it regardless of mechanical condition.

On the block you got, the cylinders look great to me. The stuff at the top is outside of the ring land area so I wouldn't worry about it. But the bearings are a worry, and like Nohome Pete says, what made those grooves and where is it now?

Man, this is a lot nicer than my $500 Mk2 Supra project (I plan to have an engine some time this year, though). Very cool get!

Is there any gunk in the oilpan?

Whoever rebuilt the engine let a little dirt slip by.  Of course the real answer is to tear it down and clean everything fastidiously and reassemble.   

I would clean the oil pan well and slip in new bearings.    

Trackmouse said:

Nice! A fellow “a65” chassis owner! Hey, if you are going through all the work of rebuilding a bottom end, just buy a 6mge (or find an NA 7mge here in the States, but good luck with that!) the 6mge were JdM yo! Only, but they were 200hp out the door. Which is plenty for that chassis. Or just 1uzfe swap it. http://www.celicasupra.com/forums/showthread.php?56444-Mike-s-(Supersubs-s)-Big-Boy-Build#/topics/56444

I’ve read that thread all the through already and the amount of ingenuity in that build is incredible. While I wish I could build something like that, this car will be relatively stock.

When I bought this engine it had already been torn apart and partially reassembled to replace some seals. So any evidence of what caused the bearing wear is long gone.

I know the proper answer is to tear it down and bring it to a machine shop to have it gone over, but I’m trying to keep this as cheap as possible at the same time. 

After the initial post I found a known running engine posted for $100 locally. I’m thinking I’ll probably pick that up and throw it in and then take my time and rebuild this one properly.

And because I know everyone likes to see engine carnage this what I found when I pulled the original engine apart.

Yikes! I recommend you swap in the cheapest yotA straight six you can find. They all net about 200hp, which, like I said before, is perfect for that chassis. 

Also, personal gripe here, but the trim around the taillights needs to be painted back to black. Someone painted WAY too much silver. 

Holy cow something taught that rod a lesson.

I'd redo the bearings anyway. You're already this far into it.

Solid looking car. I agree these are criminally underrated.