1.9L wbx main bearing wear question

[Paul Lee]

Hey everyone. I'm rebuilding my 1.9L wbx and am finding that the more I learn, the more I don't know. I'd assisted on a couple of builds in the past but this is the first time I'm doing all the measuring and thinking. Definitely challenging and fun but I still have a lot to learn.

The motor has about 90K on it. 35K of which were by me and I'll admit that I was pretty hard on it. It ran hot on occasion and lost oil pressure once where I had to drive a little ways to find a safe place to pull off the road.

I've learned a great deal about these motors from tencentilife and others on STF and thesamba. The #1 thrust bearing has me spooked. Hope it fits snug.

My question is regarding the condition of the old mains. My pictures aren't the best but I think you can see the wear, discoloration and scoring alright. Is the discoloration from the babbitt material wearing away, form heat, or other causes? The backs of the bearings show wear which had me puzzled. Does this mean they spun?

I'd really like to hear what you guys think. Any information or advice about the bearings or otherwise is greatly appreciated.

main #1




main #2



main #3


main #4


Here are the saddles on one side.

main saddle #1


main saddle #2


main saddle #3


main saddle #4


Thanks

[Paul Lee]

Was thinking about this and thought I'd add a few things. The rebuild is kind of on hold right now. I had a machine shop measure and polish the crank as well as doing some other stuff. After some poking around and a little research I decided it would be beneficial to check everything myself because I'd rather be sure about the measurements but also because I want to learn how to build motors. So I picked up a set of outside mics and a dial bore gauge. My measurements with the 1-2" mic are spot on with the machinists. But my measurements with the 2-3" mic are consistently .0003-.0005" under the machinists, no matter how many times I check it with the standard and zero it out. Since I don't have any prior experience with these tools I decided that I need to check them against a third set to be sure. Been trying to arrange it with a friend but he's been busy and the blizzard threw things off for a while too.

Another thing is that when I was fooling around with my new dial bore gauge on one of the old bearings I noticed that it was scratching the surface enough to where I could catch my fingernail in it. Not being sure if I was doing something wrong I decided to stop. Don't want to damage the tool but also because I was wondering if the old mains could be reused. I've heard that you can smooth them out sometimes. Doing everything for the first time and trying to avoid problems makes for slow progress.

Then there's the unique 1.9L #1 thrust bearing. I didn't check it before tearing the motor apart. Kicking myself in the ass for that one now. Not sure what I'll do if it turns out to be loose.

So that's where I'm at, as far as the bottom end goes.

[joop]

I never reuse old bearings! I buy them from: http://www.kaefer-co.de/index.php?view= ... size=large or BAS but I'm almost sure you can get them also in your area....
measure your crank and put together your case (clean & emty) torque the bolts and measure your bearingsaddles.
But.... in pactice, when I worked in a MAN/VW garage, we only measured the crank (then only when it looked doubtfull) and did a fingernail check on the saddles and mounted some new bearings. They never came back and had hard times as buildersvans
We checked the bigends better (2.1) because these engines will let go a rod sometimes even from new.
The bearings can't rotate in the saddles if the dowelpins are in (and not flush with the surface)
I wanted to take some pics of old bearings but my wife took the camera with her to work but they look the same as yours.


Joop

[pocketrocket]

The all aluminum VW thrust bearing always have been a problem. VW in 86 went with all steel backed brgs and the 2 steel thrust shims. All of the 3 large main brgs. are steel backed, and for good reason. I have seen the problems with the VW drag bugs for years pounding the thin all aluminum thrust bearing and it was made worse with the flanged cranks that had the split thrust. The 1.9 block is just not up to the task of supporting the load put on it in a heavy vanagon. Be sure to mic the thrust to see if it has been damaged if it has the block is on the border line of junk. If these engines are ran low on oil I have seen them warp at the center main and pound the brgs. in to the block, again junk block. Line boring will not always fix the problem. If I where you I would look for a good 2.1 block to build off from. Rocky

[Paul Lee]

Thanks for all the info and links, joop. Looks like I need to polish up on my German.

Thanks for your reply, Rocky. I'm going to mic everything out carefully. I'd been thinking about finding a 2.1 too but wanted to see if my 1.9 is still good. Even though it's a bummer in this case it's interesting to learn about the design flaws.

I'm going to check and mic everything as soon as I figure out what's what with my mics. Guess there isn't much to say about the old bearings. I know that I still have a lot to learn so thanks a ton for your help.