Questionable machine work.

[N Wolf]

I sent my 91' 90hp to the machine shop after a high speed over heating. I had it bored .030 over. When I picked it up the guy told me that he couldnt use his bore machine on it so he cut down a set of stones and honed it .030.
Now, I dont know what kind of hone he uses, but the spring loaded ones that Im familier with couldnt do that and not be out of round.
Im going to check it today when I get home to see the exact measurments. My question is how far out of round can it be and still be useable?
The guy builds race engines so I would hope he wouldnt send me out the door with a block that he turned into trash (forgeting of coarse that I blew the motor by unhooking the over temp alarm:redface.

 

[pnwboat]

Re: Questionable machine work.

Factory specs call for a maximum out of round 0.0005 in. and maximum cylinder taper of 0.002 in.

 

[Frank Acampora]

Re: Questionable machine work.

Sounds questionable to me. I have always been told what you said: Honing too much will distort the bore, especially since the bottom is closed and the stones can not be run through.

 

[N Wolf]

Re: Questionable machine work.

As for the stones not running through, he cut down a set to work. Turns out he knew what he was doing after all. I took home a set of bore mics from work today and they all three measure 3.404 all around and down. Thats .029 over but by the time I polish the cross hatch (its a little rough) it should be perfect. My apologies for questioning a professional.