Super 90 rebuild

[Vic Skirmants]

+1
I'm also of the opinion that cast iron cylinders stay rounder, and are the best material to drag a piston ring across.
Until someone with magic cylinders blows my doors off in a race, I'll stick to CI.
Mike, thanks for the back-up.

[Dick Weiss]

Harlan,

A follow-up of differences between the 50mm and 55mm #1 main bearing:

1. I (and others surely) wondered why the 2-piece 55mm bearing shell has 70mm dia. face/flange, but narrowing its width didn't make
sense in needing the thick shim dia. to match the bearing's face dia.
2. The all aluminum 50mm 1-piece shell's face width is wider and just needs the 65mm shim dia. to match t's face width.
3. However, the S90 having its large oil pump feeds the crank journals thru 4-holes and larger face notches vs. the recessed 2-holes in
the 50mm bearing shell.
4. Finally, in any case, always shift to nuetral and NOT riding the clutch (in gear) intil you need to move; This will save the bearing,
shim, clutch release bearing + the disc and pressure plate, and holding the car up-hill w/the clutch is a NO-NO!

Dick