Vilhuer

http://www.youtube.com/watch?v=-ek5qv8Nmg0

danglerb

Brendan knows that shop I think.
http://engine-machining.com/

It sounds like lapping doesn't change the basic size of cylinder much, does it?

Specifically would you bore to fit the piston, or lap to fit?

Vilhuer

No, diameter is changed 0.002mm or less but it must be done just right. Silicon crystals will break if too much force is used. Too little or too short duration etc. and aliminum will remain on surface.

Bore to fit. Like lapping also boring must be done in multible steps with specific speed, movement and force. If not result will be wrong shape bore, hourglass shape for example.

Bill Ball

We just opened up an S4 motor that had been "rebuilt" and was having a variety of problems to find a cross-hatch pattern on the bores! The bores were 0.004 inch larger than the pistons too (the pistons rocked freely in the bores). ARGH! You can't do these blocks like a Chevy!