Is there a "how to.." for crank measurement, and bearing verification? Options

[Superhawk996]

Rod measurements align a whole lot closer to what I remember measuring. In hind sight I wish I had measured all journals.

Based on the number of significant digits in the measurement, it would appear that your buddy measured with a digital micrometer with more resolution than my vernier micrometers. I would have loved the opportunity to compare my measurements to his.

All engine specs from factory manuals can be found here.

http://p914-6info.net/Manuals.htm

I don't know who's site this is but it is an awesome resource.

[jtprettyman]

@Superhawk996

Yes, these were done with a very nice set of Mitutoyo digital mics in a controlled metrology lab environment. I spent quite a few years with Toyota in a powertrain facility, know my way around measurement so to speak. I mapped out the dimensions with the intent to report out X and Y axis, but there was basically zero ovality to the mains or pins. When you originally sent me the crank I just bagged and oiled it for eventual use building my original 1.8 and didn't give it a close look. When cleaning it prior to measurement I did see a couple very minor scratches, but verified no raised material on any of them. Overall, this was a very nice crank, and measured out pretty much right where you thought it would. Great to see it getting a new life with @malcolm2 , and happy to help out.

[malcolm2]

Your rods should at least have the big ends done.

Honestly if you're not doing that then it's a recipe for disaster.

OK, I am back on the engine.... at least research.

So what do you mean, "have the big ends done"?

I found rod bearings at CIP1.com that are listed only as STD or -0.010, etc... $33 for a set. I assume that the "under" listing is to note the machining on the crank. Is this what I should look for, simply -0.010?

If the rods were "done" would that mean that they have been trued up? Ground or polished or just re-bearing-ed?

Blizzard has provided me a set of 2.0 liter rods that he has balanced. So I have something to work with here. The link provided by superhawk above, only deals with 1.7 and 1.8 engines.... at least that I can find. 251 pages on the engine, so I could have missed it. So I am still looking to find the factory spec on the "big end" as a starting place and to determine if Mike's rods have been "done".

So question 1: how do you "DO" the rods?
question 2: What Rod bearings to get, how are they listed?

Thanks

[Superhawk996]

So question 1: how do you "DO" the rods?
question 2: What Rod bearings to get, how are they listed?

Thanks

1) When you have the rods reconditioned at the machine shop they should press in and hone new small end bushings and verify the size and roundness of the big end. If not perfectly round they will "resize" them by grinding a few thousands off the rod and the rod cap. This makes the big end hole egg shaped and undersize. The machinist then hones the big end back to size and perfectly round.

Type 4 OEM rods are quite robust for street use (replace the con rod nuts - don't reuse). Factory manual and Peter Russek reference at the time didn't recommend servicing the rods for big end sizing. Only replacment of small end bushing. That would have been in an era where replacement parts were still readily available. Tom Wison book advises to have big ends checked but really doesn't show specs to "resize". At a bare minimum have them checked by a machine shop with the capability to recondition rods.

If you don't already have a copy of the Tom Wilson book, get one. It will be the best investment you can make if you are going to rebuild a VW engine yourself.

2) Get 0.010 undersize bearings. As referenced in step #1 above, the rod big end is or will be reconditioned to factory size (50mm). In the case of the undersize bearing, it will be .005" thicker on each half to take up the "extra" space that was created by grinding the crank undersize.

Sorry on the bogus link. I didn't realize that link only covered 1.7L & 1.8L.

Here is an alternate link that referenced Type 4 big end sizing.

https://type4secrets.blogspot.com/2017/08/t...cting-rods.html

[malcolm2]

Rod Balancing, End-to-end. I also wondered how in the hell do you balance END-TO-END.

I found this 20 minute video (balance at 6 minutes) where he hangs one end on a nail and puts the other end on the scale.... weighs each rod and compares, removes material, repeats....

is that the way to do it? Good way, Bad Way???

This link and the embedded vid starts at 6 minutes.

https://youtu.be/U3IXSywgTnM?t=386


https://www.youtube.com/watch?v=U3IXSywgTnM?t=386