Author Topic: Need some specialist advice about a bore and pistons?  (Read 1330 times)

Offline clipperjay

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If you just cracked off a valve plate to a compressor and found that the reeds had snapped off the mount and pretty well scored and chipped the crown also the crank case is pitted on the outer edge and has light scratches on the inner bore? Whats the best way to fix the bore as I can't really get bigger piston on it due to specs, is there a possible light skimming to the bore which would have no affect on the diameter of rings, or rebuilding of the metal and no a sleeve won't work on this compressor?  :undecided:

Jay

Offline danny_p

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Re: Need some specialist advice about a bore and pistons?
« Reply #1 on: 15 January 2011, 15:59 »
meany ways of dealing with it depending on how seriouse the scratches are.

if it's used lots and they are deep and larger piston is't avalible it is possible to bore it out then have a liner pressed in and bored to the correct size for your old piston. 

if they are deep but the machene recives littel use,  it's amazing what you can do with JB weld,   degrease the block  fill the scratch / den in with jb weld and trim to shape, rub some 240 grit sandpaper about in there and try the piston out and see if it runs smooth enough.

if there not that deep and it's not used much just put your hand over the top of the bore and feel if it makes reasonable effort at compression if it dose just   rub some 240 grit around the bore and  make sure the piston is free of burs  slap the head on and try it,  if it works just forget about the scratches.

the 4th option is just buy a 2nd hand compressor complete or just the pump off ebay.   my 25 cfm broom wade needs its rods reshelled atm :( 

all the VW's have gone bar 1.

Offline Thom89

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Re: Need some specialist advice about a bore and pistons?
« Reply #2 on: 15 January 2011, 19:11 »
Slap it back together, part ex it with a new one, off set it against you tax... :wink:

Thom

Offline Mikester

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Re: Need some specialist advice about a bore and pistons?
« Reply #3 on: 15 January 2011, 19:14 »
Why dont you get some overnight parts from Japan?

Offline clipperjay

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Re: Need some specialist advice about a bore and pistons?
« Reply #4 on: 15 January 2011, 20:52 »
This is a (Freezer) compressor cost £5.5K and it was in off topic because its not in a car, but principles are the same in terms of motor.
I'm going to order four new pistons might as well do all of them as there was light pitting on the other two pistons crowns, its a V formation engine.
I'll get a specialist rebuilders on monday, but just a real pain that a reed had broken at that mount when they are designed to bend if under pressure?
 

Offline danny_p

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Re: Need some specialist advice about a bore and pistons?
« Reply #5 on: 16 January 2011, 14:16 »
i thought it was an air compressor as in workshop.

at that value new pistons and bore sleeve bores if required
all the VW's have gone bar 1.