Rebuild or Replace?

Neodeuccio

Addicted to boost...
Sep 30, 2006
846
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Schenectady NY
I'm faced with with a problem and i don't know what the best way to solve it is.

Last year my 88 7mgte threw a rod. Well, this is an assumption. My car pretty suddenly started making an outrageous racket. Kinda of like a pissed off midget inside my engine with a sledgehammer. Not a happy sound. I figured it was a rod, and my mechanic agreed after listening to it. I should also note that Dave (mechanic) specializes in Mk3's and is a proud owner himself.

Now, I need to decide if I want to get a new (used) engine, or tear apart the one I have and put it back together so it's happy. The engine I have has a damned-near new top end. When the HG blew a few years ago, it was replaced with a Titan 1.4mm MLS gasket, new cams, new valve train, and a new cyl head. Assuming that the piston isn't slamming into the head, this all has less than 5000 miles on it and should be fine. The rest of the engine has probably about 155k on it. I can get a new crankshaft, with bearings for under $400 from NAPA, so adding in rods and possibly pistons, I'd be looking at maybe $600 give or take for parts to rebuild the bottom end. If I bought e new engine, I'd be spending at least that much on the engine itself, not including the cost of shipping/pick-up.

Another problem is that I can't afford to have someone else do the work, so I'd have to do it myself, regardless of which route I take. I do have some friends that would help me out, and are pretty knowledgeable, but none of them have ever worked on a supra before, and though I'm not quite noob-level, I've never done anything as complicated as a tear-down and rebuild or an engine swap. Either way, I'd be looking at doing a shit load of reading, then diving in and learning the rest as I go.

I kind of like the idea of rebuilding the bottom end. I can get the parts locally, which is nice, and I know that the rest of the engine is good. Or rather, I know where the rest of the problems are. If I get a new engine, I really have no idea what I'm getting, no matter how good the reputation of the seller is. On the other hand, I am guaranteed a running engine from the get go, and the various engine importers/resellers out there all offer support to an extent.

So what do I do? Any advice will be greatly appreciated.

PS- If you want to help, that would be appreciated too! :biglaugh:
 

NewWestSupras

SoupLvr
Mar 1, 2006
611
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White Rock
I'd rebuild it. Those engine resellers might replace it if it's toast, but they don't pay for re and re, so it turns out to be alot of work. If you rebuild it yourself, you know exactly what's going on inside... If you have a good place, tools, engine hoist, engine stand, patience, and lots of help, that is. gl.
 

CajunKenny

PULL MY FINGER. PLEASE!
Nov 15, 2007
3,255
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Washington
I also say rebuild it.

I went through three JDM's before I got one decent enough to go through and re-gasket. In all three JDM's that I took apart, none of them were 'Drop-In'. The first one had been run low on oil and had a toasted top end and the second one had a BHG on #6 and a badly eroded water jacket. Also, those engines sit for long periods of time and sometimes out in the weather so a lot of the gaskets/seals are dried and brittle.

If you get a JDM, tear it apart and regasket everything! And of course inspect as you go.
 

solpower

New Member
Jan 26, 2009
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Albemarle, nc
rebuild lol youll learn alot and its good bonding with a friend or 10 lol plus even if you ordered a motor it would be a bone stock 7m and youd probably wind up having to rebuild it soon anyway
 

CyFi6

Aliens.
Oct 11, 2007
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tbcmorris;1264882 said:
Ok forgive me if this was said...I wanted to touch on something...piston won't slap the head unless you have some hairy cams...we are a non contact engine

He means when the bearings gave out it allowed the piston to move up farther in the bore than it should thus smacking against the head.
 

deabionni

The Lurker
Sep 16, 2007
431
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Kalkaska, MI
I had a wrist pin come apart in the #5 cylinder of my old GE engine, and I can tell you that the piston DEFINITELY slapped the head. :D
 

Neodeuccio

Addicted to boost...
Sep 30, 2006
846
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Schenectady NY
So how hard is it to tear apart the bottom end and replace the crank, bearings, rods, etc? I don't have a lot of time to work on it, maybe an day each week, but should I count on not being able to drive her at all this summer, or is there a chance I'll get it done in time for an August cruise? Also, I've seen these dvds for sale on EBay that say they're a how-to for rebuilding a 7m. Anyone know if these are any good or if they're a straight up waste of $20?
 

tbcmorris

SM Expert Thread Derailer
Mar 14, 2007
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PRUVEN PERFORMANCE MILFORD CT
CyFi6;1265199 said:
He means when the bearings gave out it allowed the piston to move up farther in the bore than it should thus smacking against the head.



I understand that...I don't think it wouldnhit even if there was no bearing left. The bearings aren't that thick....if you head is good slow66 is selling a built block....that is what I would do is buy that
 

CyFi6

Aliens.
Oct 11, 2007
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To do all the work you listed, you would have to pull the head so you could get the pistons out, and of course by then it goes into, why not just do a fill rebuild on the shortblock which will cost you in excess of 1500 dollars probably
 

NewWestSupras

SoupLvr
Mar 1, 2006
611
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0
White Rock
I hate like hell to say it, but if time and money is an issue, perhaps shelve the idea of "fixing it quick". Find a beater to get you around, and plan for a slow, meticulous engine rebuild. Or find a big bag of cash and buy a bottom end that's already done. That way you can mate your newish head to it with min. downtime. It's all money with these pits. gl.
 

Kckazdude

Active Member
Mar 16, 2007
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Memphis, TN
Since noone else has stated the obvious, until you do some more inspecting to it, nobody can tell what direction to go in. For all we know you have a straight 6 boat anchor sitting in a Supra.
 

sneakypete

Regular Member
Jul 18, 2007
1,129
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Central NJ
i say rebuild it. if u dont have any true experience with assembling and engine, or dont know anyone with experience who will help you every step of the way...........get a machinist to do all the machine work and assemble the rotating assembly and oil pump bearings. you can do the rest with a decent set of tools and lots of time and patience.

find a good machinist that your comfortable with. take a look at his shop and see what condition its in... if its messy, then his work will probably be sloppy.
my machinist charged me $1100 for the labor which included machining, rotating assembly (crank, rods, pistons, bearings), installed oil pump and bearings, rebuilt the head with a 5 angle valve job, cleaned everything, freeze plugs, various other little things, and most of all... dealing with me

if ur on a budget and only need the bottom end worked on, start buying all the parts required and get some quotes
good luck
-pete
 

WhtMa71

D0 W3RK
Apr 24, 2007
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Macon, GA
Kckazdude;1265386 said:
Since noone else has stated the obvious, until you do some more inspecting to it, nobody can tell what direction to go in. For all we know you have a straight 6 boat anchor sitting in a Supra.

First reply.
WhtMa71;1264818 said:
Have you actually taken it apart yet to see what damage has been done?
 

ForcedTorque

Join the 92 Owners Group
Jul 11, 2005
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I don't know how well known this deal is, but Ace at Zankoku Performance sells a rebuilt long block for $xxx. I bet that would drop even lower if he used your good head and gasket. That would probably get you a good inspection to be sure it is still OK.

EDIT!!!!! ZANKOKU WAS NOT THE SOURCE OF THE BLOCK I REMEMBERRED. The source was 927mgtePat, who is now banned. Sorry for the bad info!
 
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