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

[malcolm2]

I am gonna make a 2 liter from my 1.8. So I have a refreshed 71mm crank that I have been told has been ground to -0.010.

I measured as best as I can with a digital mic and got about 59.66 on the mains and 49.65 on the rod journals.

Where can I find the STD specs and ranges ? were they 60 and 50, respectively?

Since I know nothing about this crank, how can I verify the 71 mm measurement?

[Mark Henry]

Sounds like a lot. If you're right about #4 you'll be lucky to get it ground at .010 under.
You need to send it to a crank shop, once done they will tell you (tag) what sizes you need. I never use plastigage, nether does Raby IIRC. Your rods should at least have the big ends done.

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

[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