speedrace

A little history -- I bought this car about a month ago, and drove it exactly three times before it started running up on the temp gage when on the open highway. A lot of people on this forum tried to help me out in getting to the bottom of the problem, and I thought I had it licked. But then after a coolant system pressurizing test was done-- I waited 5 minutes looking for a pressure drop (it only dropped 2 psi from the 15 psi I pumped it up to) --- the damage was apparent. It blew on the last cylinder and filled it with coolant.

Instead of just pulling the head and doing a gasket replacement, I was advised by a couple of local guys that run shops that I might be throwing good money after bad if the head was cracked or the bearings saw too much coolant (which ruins bearing babbit material in short order)


I'm hoping to be back on the road soon. I pulled the original (172K) motor and the trans as one unit last weekend. Now I'm making the engine compartment sanitary, and transferring parts over to a import GE longblock I bought from Engineworld for $500 -- that carrys a 6 month/unlimited mileage warranty on the long block.

Thing is-- once you get into it you find all sorts of other things to replace. The list goes on:

Clutch (old one was just about gone--despite no slipping)
re-surface the flywheel
new pilot bushing
new starter (old one locked up against the flywheel when the engine hydraulic locked-- probably ruining the starter drive)
Cam Cover gaskets
front and rear crank seals
timing belt
water pump
intake and exhaust gaskets
Serpentine belt
Radiator hoses
Another new thermostat ( can't trust the one that got hot when the HG Blew)

I have to swap the oil pan with a new gasket, as the engine I bought has the pan sump up front-- instead of in the rear like the original SC one. Maybe the import used long block was out of a Supra? I'm also assuming I have to change over the pick-up tube.

I'm going to pull one rod cap and one main cap-- as long as I'm in there to make sure the bearing babbit looks to be in good shape. Then pour some Magic Marvel Mystery Oil all over the camshafts before re-fitting the covers, and spraying some sea foam onto the piston crowns to loosen up some of the carbon that I saw when I used a borescope down the spark-plug holes.

One other thing I'm still trying to figure out has to do with the Fan clutch. I'm thinking mine is bad, as when the engine would get fully warm (even too-hot a few times and I'd shut it down quickly) -- I would turn the engine off, and I should have felt some resistance when trying to turn the plastic fan by hand--as the way I understand its operation it locks up more solid to pull more air volume through the radiator shroud when in traffic or slow driving conditions. But it turned just as free as when the engine was stone cold.

Any comments on that subject?

I suppose this would be a perfect time to fit a short throw shifter, but the only ones I've seen are priced high at $275-300. Any others out there?

My budget in getting back on the road is already stretched.

cliffud

iTrader: (3)

you are brave man. keep up the good work, sounds like your SC will have no problems running another 172k when you're done.

na4now

That long block is a good idea.

What all do they replace?? I wonder if they build it back, as good as toyota did?

na4now

I called engineworld in emeryville, ca. They said they only offer a used jdm engine, and its $495. Did I call the wrong place?

TheMole

iTrader: (13)

Props for fixing it right. Can't wait to see it completed.

speedrace

You did call the right place (EngineWorld) and yes-- it was a used import long block that I bought for $495. I have a flexible borescope that I used to check out the cylinder bores--through the spark plug holes, and look for any evidence of a head gasket problem, such as a clean spot on any piston, or oil and/or anti-freeze drips around the head gasket interface--- as I can rotate the scope around and look at the mating surface between the head and block on each cylinder.

So if it passes the inspection of the lower-end bearings as I described (pulling one rod and one main cap) with no copper showing on a bearing shell, and no pits in the babbit material--- then I feel the engine is good to go with the new gaskets, seals,pump, and timing belt fitted.

joewitafro

how is a JDM engine the "correct" way to do this? The correct way would of been disassembling your motor for a rebuild. New rings, fresh hone, new bearings and a fresh head gasket after having the block and head checked for flatness. This motor.. I highly doubt will last you another 100k. JDM motors are ran to the ground.

speedrace

Joewitafro--

Of course you are right-- to really do a complete job, I would have stripped my existing engine down to the block, had the head pressure tested and crack checked. Then check the cylinder bore for roundness, and the deck for flatness. Then-- re-build from the ground up.

You want to get the rods re-sized, the line bore checked, new pistons, bearings and rings....freshen the head..and the list goes on an on.

However-- that route would have easily tripled my cost to get the car back on the road. A priority-- since this is my only daily driver now. I know the JDM route requires a leap of faith, but I have carefully checked the engine over, and my goal here was to get it back on the road for a grand-- and pull down the other engine to build it back up for a NA-T conversion at some future time.

If I can get a couple of years of reliable service from this JDM based engine then I've met my goal.

I am curious about one of your statements. You said the JDM engines are run into the ground-- and I understand they are probably subjected to a lot of stop and go driving in their home market-- but the lower accumulated miles still makes them a value-- if you know what to look for....I think.... Tell me something more about them-- so I can be more aware of the situation.

Thanks

joewitafro

Okay, I'll explain my post. I wasn't coming off saying you didn't do the right thing as an alternative to get a cheap fast "band-aid" fix. But I didn't like how you labeled that you were doing it the RIGHT way, that is the problem when these young teens go and buy a JDM engine to fix ALL of their problems, and end up with the same effing problem.

I can list some examples for you. My car had a JDM motor, blew a head gasket and the previous owner had a MHG installed (block was never milled though).. 2 months later the bottom end spun a bearing.

I completely yanked the motor apart and rebuilt the whole thing, $1,600 incl. labor for the machinist. That includes pistons + rings.

My brother bought his supra as an NA auto car with the motor in the trunk. He read all over the forums and was advised to pick up a JDM motor so he did, the motor came on a broken palet with a damaged oil pan, and no compression or leak down numbers.. But they "assured" us that they were good. His motor blew a head gasket a week later... After replacing that, guess what.. spun a rod bearing. He also had the motor rebuilt at the same machine shop as I did, and now he's putting down 325rwhp on the stock CT26.

My brother is a mechanic now, and a couple weeks ago he ordered a JDM engine for a guy doing engine overhaul on his Mk2 supra (5mge). My brother advised against this but he did it any ways. Motor came with no compression numbers or leak down test done to it. They having started the car yet, but are HOPING it is okay.

While the 2jzge motor isn't known to "blow" head gaskets, looking at the inside of my motor, and my brothers.. these motors are ran hard, We look inside the motor to find they arent taken care of as far as sludge build up, and the valve train looking like poop. Low grade gas and lack of maintenance.

I hope you the best, but if you were going to go NA-T any ways, aren't you going to be rebuilding your motor?

speedrace

joewitafro,

I agree that I probably should not have chose that subject line, but what I was getting at was that just throwing a HG on my original motor involved a lot of my labor and a "dice throw" on the condition of the internal passages on the head, block, rings, bores, etc.---- because it almost pegged the temp gage a couple of times while I was trying to get to the bottom of why it would overheat only at a sustained speed on the highway.

I didn't want to throw all the parts money at a HG replacement -- only to find out it had other heat-related damage elsewhere.

But I have taken your experience on JDM engines to heart. I think I will pull the head off of this one after all, remove the carbon, check the piston to wall clearance (side to side) and if all looks well fit a new HG. I have not seen any sludge build-up, nor are the cams colored with brown deposits from too long of oil change intervals.

As far as my original engine, if I do find a way to build a NA-T engine down the road it would have me stripping that one to the bare block, having a mag particle crack-test done on the deck and bottom main bearing area, crankshaft journal fillets, etc.---- and then fit oversize forged pistons to get the bores round again. Line-bore it. Fit ARP studs at both ends and look around for a GTE cylinder head.

The problem here in Northern California is that to use such a car on the street you have to register it out of state. They frown at you here if they even see a K&N cone filter on the engine during the visual part of the emissions test.

qksl2

I own a shop that does 5+ rebuilds on high end performance cars per month, and I can tell you after handing over a $5k+ bill for a proper rebuild that a low mileage used motor will be far cheaper and can work for a long time. You take a chance when doing that, but most shops don't know how to rebuild a motor as well as it was originally put together. People think we are crazy when we give them estimates, but to do it properly, we dedicate a ridiculous amount of time and attention to detail to make sure it exceeds factory tolerances. We also use a machine shop that is 3-5x more expensive than the yellow pages places. My point here is that unless you have the tools, knowledge, and resources to do a very, very good job, you can't beat a warranted $500 motor if you can't budget the several thousand a rebuild would take. Just don't consider it a performance motor because you don't know where it came from.

One thing for sure, though: pull off all the mains and all the rod caps. I'd replace them all. They are cheap insurance. If you pull the pan, swap the bearings; general rule of thumb. Also, front and rear mains for sure.

Ian

speedrace

The more I checked out the JDM engine I bought, the more I tore into it. I finally took it all the way down with the exception of leaving the pistons and rods in place. I checked out the valve sealing in the head, and also checked it for flatness, and called it good.

But as it turned out, I spent more on new parts for this engine than I did for the engine itself.

A list of all new parts and stuff:

Water pump
cam belt
cam belt tensioner
cam belt idler
flywheel bolts
serpentine belt tensioner pulley
Toyota OEM head gasket
ACL Race-- main and rod bearing set
all new fuel injector o-rings (toyota oem)
front and rear main seals
cam cover gaskets
oem clutch disk
pilot bearing for the 5-spd input shaft
clutch release bearing
all o-rings related to the cooling system
1997 TT Supra front motor mounts
oem oil filter
gallon of the red coolant from a Toyota dealer
6 quarts of Royal Purple Synthetic
a tube of the toyota oem black sealant for the pan, cam housing, etc.

Pic shows the build with about 3 more hours of prep before lowering it back in.

Oh!-- I also caved into the temptation and bought a V3 short-throw shifter from Suprasport.com

I'll post a finish pic when I'm there. (hopefully by this Saturday afternoon).

And I am going to take the advice given here to run petro oil in in at idle for about 10 minutes ---until warm--- and then drain it and change the oil filter to the good one I bought and fill it with the Royal Purple.

joewitafro

Looks good though, hopefully all is well on the bottom end. Did u inspect the main bearings and rod bearings?

speedrace

Yeah-- I inspected all the bearing shells. One main had a small particle embedded in the soft babbit (but didn't scratch the journal--just like its designed to do). The rod bearings were just starting to change from the light grey color to the darker grey sub-layer color ---- and so I decided to yank them all, with the crank.

The journals were all in excellent condition. So I flushed it with solvent, and fitted the new ACL Race bearing set w/ thrust bearings also. I plasti-gaged every journal and came in between .0015 and .0020

I decided against a micro-polish and flush from a machine shop--on the crank, because they would have had to drill out the plugs and then drill and tap for new ones.

qksl2

Make sure to clean out all the oil galleys to make sure there isn't anything in there that will get lodged in the bearings.

Ian