<VV> '63 Turbo crank journal clearances

[Nick R]

Hi

I'm rebuilding my '63 Turbo motor. This is my first Corvair engine rebuild.
Today we plastigaged  the main bearings for clearances. We did it by the GM
Service Manual.

Clearances were like this.

Main Journal #1= .003 (has the different style bearing with thrust surfaces)
                       #2= .003
                       #3= .003
                       #4= .002
We are thinking that these numbers are within tolerances and I will not
benefit from replacing these main  bearings with brand new main bearings. I
would be interested in hearing from more experienced Corvair engine
rebuilders out there so that I might draw valuable input from more
experienced Corvair mechanics.

I will not be torture testing this motor, exceeding red line.
(Intentionally that is!) I do not want to reassemble it with bearings that
will cause my motor to grenade when I spool the turbo a bit now and then to
keep the turbo limber. I understand that missing a gear can undo all of my
hard work by causing an over rev. No racing.

The problems I found when we opened the engine up were as follows.

5 of 6 top compression rings were cracked.

#1 piston skirt was cracked across the skirt but intact.

All 6 skirt clearances were about .005

I've sent the heads out for rebuild by an experienced Corvair technician.

I plan on buying new rebored cylinders pistons & cast iron rings .020 over

The camshaft measured out with very little wear. I plan on reusing it with
new lifters.

Thanks in advance.