VW 1.8 8V Strange Crank/block/bearing wear, is this junk? (dialup warning)

[Tom A]

A friend gave us a VW 1.8L 8V GTI engine a couple years ago as a core. We redid the head last year, but just this afternoon tore down the bottom end to get it rebuilt, and found some interesting wear.

The #3 bearing is ground almost completely away on one side. The sides of the #3 bearing that go on each side of the journal and one side is ground down pretty badly, there is also some wear on the crank and on the block/cap on that side. The really strange thig is this is the only place that shows this wear, all of the others look fine.

I am a little confused as to the cause of this, and I don't understand how the wear is only in one spot, on the #3 bearing. I would think if the crank could move enough to do this, it would have done similar damage in other places.

I was planning on taking this block and crank to the machine shop next week to get prepped for a rebuild, but am thinking at this point that it is probably junk. Anyone know anything about these?


#3 Bearing:
http://www.shedracing.net/misc/bearing.jpg

Crank:

http://www.shedracing.net/misc/crank.jpg

and on the block and cap:

http://www.shedracing.net/misc/block.jpg

Thanks,

Tom

[msogren]

That is what happens when the nonstcok thrust bearing is used. They have about 50% surface area of the stock , mulitpiece , thrust bearing. The high performance pressure plate ,and a driver that starts the car with his foot on the clutch pedal also hurt the thrust surfaces. The small thrust bearings , like you show have not been rebuildable , due tothe wear on the crank.
I try to use a auto crank and save the old thrust bearings, like gold nuggets.
best bet is to find another crank, check the block fit,with a 6 part bearing setup, and go from there with the block. the blocks are so common tho ,That i'd would go for a complete used block/crank assembly, Try for the automatic version, as the flex plate doenst load the thrust bearings.
FWIW, a lot of the 88-91 auto cars had the best engine codes and some had the two pipe manifold , along with the best cam/ piston and a few have the German head.
If the donor car has rear disc brakes, and an auto, it is most of the time a German built car and may have the best parts,IMHO, MM

[Tom A]

That is what happens when the nonstcok thrust bearing is used. They have about 50% surface area of the stock , mulitpiece , thrust bearing. The high performance pressure plate ,and a driver that starts the car with his foot on the clutch pedal also hurt the thrust surfaces. The small thrust bearings , like you show have not been rebuildable , due tothe wear on the crank.[/b]This is strange, because I don't think the engine has been rebuilt. The guy who gave it to me said it only had 117K miles on it when he pulled it to install a 16V engine.

That bearing looks exactly like the one shown in the Haynes manual. Did some engines come with that type of #3 main bearing?

Thanks,
Tom.

[Conover]

I'm pretty sure that those bearings are never present on a factory engine. That engine must have been rebuilt. Don't ever use those two piece #3's always go for the six piece action.

[Kazoo]

We had a street car many moons ago with that kind of wear. Went through two engines before we actually found the problem... Bad Clutch Pressure Plate. Required way too much force to overcome the spring and was transferring this force to the thrust bearing. We didn't really know there was a problem until the car wouldn't start and blew the dents out of the oil filter, then oiled down the driveway! Metal and bearing material got into the oil pump relief valve...Oil pressure spiked, blew up the lifters, held the valves open and Taaadaaa... no compression, but a hell of a lot of oil pressure!

My guess is that it had nothing to do with rebuilds, or what bearings were used...most likely the car was driven for a while with a bad pressure plate.

Good luck!

[Tom A]

Thanks for the reply. We will put new clutch parts in when we put it back together, assuming we can put it back together. I suspect the block is fine, the bearings didn't wear all the way through. The crank is grooved, and I suspect it is probably junk. I will drop it off at the machine shop anyway, it is still worth checking.

I am still confused about the #3 bearing, as all three manuals I have, Haynes, Bentley and John Muir all show bearings that look exactly like the one pictured. None of them mention a multi-piece bearing.

Tom

[joeg]

The crank is scrap; the block should be fine.

Multi-piece thrust bearings are used in Europe by a variety of manufacturers. I am sure you would have to do some looking to scrounge up a set. I have seen them in a Haynes for my Fords and noted that they looked interesting but added to assembly time--which could explain why they are not used elsewhere.

[Sandro]

I just finished rebuilding my block and your right Bentley just mentions that the thrust bearings go on #3 they also dont mention that the full groove bearing goes on #4.

I had trouble finding the 6 piece bearing set but I did find it. If you can't find them let me know and I could get them for you locally and send them to you.

[msogren]

I built a rental 16 V ITA car about 8 yrs ago. The renter, bought it from me, and then traded the engine from a wrecked race car, with a "Pro" built 8V and a quaife trans. I just bought it back and went thru it today. I wanted to check the pan and see what kind of oil control was present..
It has the little , single thrust bearing!! POS. It just shows that no matter how much you spend on an engine,many "Pro" shops use the cheap stuff. Dont assume that just because you spent 4000$ for an engine, that it is right. It does not have Total seal rings , or the good thrust bearings.
Both, needed for power and long life.
I just dont see how 4000$ can be spent and have this kind of crap.
FWIW if you use a normal chevy style , engine machine shop, they might not use the right bearings. You have to buy an extra main bearing and the 4 extra pieces of thrust bearings. Or use the old ones. They are usually fine, if the crank can be used , standard size.
The little thrust bearings last about 100hrs, the stock ones may last 10000 race miles, with synthetic oil.
MIke Ogren

[Tom A]

To follow up with this, We tore down our other spare core engine, and found the mystical 6 piece center bearing.

It looks like the #3 main bearing itself is the same as all the others, but there are 2 piece thrust bearings on each side of the journal and cap. Here are the thrust pieces:

http://www.shedracing.net/misc/thrustbearing.jpg

The 2 on the left go on the block, the right side ones go on the cap. The tab on the cap thrust bearings fit in the notch on the cap that can be seen in the first photo.

The local machine shop who will do the work can get the good bearings, so it looks like am in good shape.

Thanks for the help.

Tom