Thread: Question for Pat

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Pat can you explain to me, in detail....why machine shops want your piston's before boring your block
Thanks

Well, I'm NOT Pat, but it's really simple.

A quality machine shop will mic each piston and bore a given cylinder for that particular piston. Generally this is done only on race engines where tolerances can be critical.

However, manufacturers do vary slightly in setups when they machine parts (any part, not just pistons) and a good machine shop will want to know what they're dealing with before they start "whittling away" on a block.

Hope that helps.

Measure twice bore once

I'd like to add my comment here also---we want the pistons when we bore/hone the block as we will fit them to the bore

The mains get align bored/honed to standard size as there is no wear there but the pistons/cylinder walls wear so the motor will take bigger pistons on rebuilding

we do not use CNC machinery as that is about like the factories and is the reason folks like us old timers do it one hole at a time, straight and round---the cnc guys want to do hundreds so often they have hundreds wrong-- this individualized service is what blue printing is all about

we make a lot of money correcting the inexperianced CNC shops work, including many of the online shops work

but---what ever blows your dress up

Originally Posted by 198plus

Pat can you explain to me, in detail....why machine shops want your piston's before boring your block
Thanks

well even new pistons are off 0005 to .001 in one set so it nice to have them before you hone to size. if i am boring a block i will not bore and hone it less i have them in my hands .i like to hone out amount that work s for me with my boring bar so i set the boring cut so i not taking out 006+ with the hone so it nice to have the pistons. but if some just wants me to bore and not hone then it 005 under the the final size like a 030 over would be 025 THERE IS ALOT OF PATS HERE I SEE

Originally Posted by pat mccarthy

well even new pistons are off 0005 to .001 in one set so it nice to have them before you hone to size. if i am boring a block i will not bore and hone it less i have them in my hands .i like to hone out amount that work s for me with my boring bar so i set the boring cut so i not taking out 006+ with the hone so it nice to have the pistons. but if some just wants me to bore and not hone then it 005 under the the final size like a 030 over would be 025 THERE IS ALOT OF PATS HERE I SEE

There is ONLY one Pat McCarthy and he gets the pat on the back from me. Thanks for always being so kind to share the wealth of knowledge you have with all our forum members! Blessings to you.

Not tyrying to out PAT the master, just offering my .02 worth!

Just want to thank everyone for there input on this thread and others I have posted........ what a bunch on great guy's on this site.

Originally Posted by geezer2

not tyrying to out pat the master, just offering my .02 worth!:hmmm:

come on stop ityou guys keep talking like that i may never go Thanks to ..styling z AND I WAS THINKING YOU GUYS DID NOT LIKE ME