Ensuring Oil Clearances After Crank and Rod Machining

[49vwsplit]

I got my case bored .020 over by a local guy and looks great. I don't have the luxury of a shop to go to where I can bring the crank and bearings and just pay for the tolerance work to be done in one shot. Believe me, I'd do it. It sucks but it will just take me more time do get it right.

Since I don't have that awesome one-stop-shop to go to, what is my next move? I measured my rods and they were a bit out of round so I will have to get them honed. Essentially, the rods will have the cap surfaces ground ~half a thou each making the journal egg shaped and then honed back to factory dims. Cool.

So....I'm sort of in the chicken or the egg situation.
I have my case turned 20 over (1st cut), thrust was checked and is spot on.
I'll get the rods reconditioned.
I need to get the crank turned and I found a shop that does nothing but crankshafts. More than likely it will be .010 under (1st cut).

What is the next step? Do I just purchase the respective bearings and trust that once the case and rods are torqued, the crush of the bearing will result in the correct oil gap everywhere?
Or do I:

- Purchase all the bearings.
- Install the mains in the case, torque the case and measure the bores.
- Install the rod bearings, torque the rods and measure the bores.
- Advise the machine shop how much to cut the crank mains and rod journals to match my case and rod measurements?

Am I way off on what I'm thinking?
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[anthracitedub]

I’d get the rods rebuilt, get the crank gone over and then purchase the bearings. That doesn’t mean things will just fit...that’s when the fun starts.
I would swing on over to the performance section and type Main Bearing in the search bar.... lots of good info for what your trying to figure out. You’ll find a great thread about dialing in good clearances for your mains... you’ll see that different manufactures will yield different clearances on the “same” size bearings. Sometimes you may have to get a few sets of mains to get it just right or have the crank polished into spec on that particular journal .

Here’s one that came to mind... plenty of others with good info too

https://www.thesamba.com/vw/forum/viewtopic.php?t=746108&highlight=main+bearing+clearance

[esde]

Buy the bearings, and measure their fit with the case halves torqued down. Do the same with the rods. Compare that to factory specs and then talk to the crankshaft grinder, or post back here.
I've had a crankshaft polished to fit some bearings that were too tight once. Sucked, but cheaper than trying a third set of bearings.
_________________
modok wrote:
Bent cranks are silent but gather no moss. I mean, ah, something like that.

[49vwsplit]

Finally got the main and rod bearings ordered, amongst other items. I also found a local guy who will regrind the rods, hone them and press new bushings in. Once I get the machined rods back I'll install the bearings, torque them, install bearings in the case and torque it and get all the measurements posted.

From there it should be a matter of accounting for oil clearance and I will be able to advise the crank shop what dimensions to grind to, correct?

I will need advice as to what the crank dimensions should be to obtain the correct oil clearance....please.
_________________
Officer: License and registration please.
Driver: What's the problem officer?
Officer: It indicates here you require glasses to operate a motor vehicle.
Driver: It's OK officer, I don't wear glasses..I have contacts.
Officer: I don't care WHO you know!!

[49vwsplit]

I tried to get the rods reworked this weekend but the guy was booked so that will happen next weekend.

Not sure how the bearings are numbered but 1 thru 4 with the flywheel being #1 and the pulley side small diameter bearing being #4.

Case was cleaned of any line bore shavings and grease, bearings installed and case torqued to 23 ft-lbs on the main 6 studs and 18ft-lbs on the 14mm nuts for bearing #4 area.

Measured 3 times per bearing taking care not to measure in the same place twice.
Measurement tools:
Dasqua Snap Gages
Mitutoyo AOS 0.0005"/0.01mm Resolution, LCD
Mitutoyo 103-922 Outside Micrometer 0.0001" Graduation

Results:
#1 1.9615, 1.9610, 1.9610 = 1.9612" (Flywheel)
#2 1.9615, 1.9620, 1.9620 = 1.9618" (Split Bearing)
#3 1.9610, 1.9615, 1.9615 = 1.9613"
#4 1.5635, 1.5645, 1.5645 = 1.5642" (Small Bearing)

Dowel pins are not in:

_________________
Officer: License and registration please.
Driver: What's the problem officer?
Officer: It indicates here you require glasses to operate a motor vehicle.
Driver: It's OK officer, I don't wear glasses..I have contacts.
Officer: I don't care WHO you know!!