Westinghouse compressor rebuild-ring gap?

[CGT80]

Need help with air compressor rebuild-new rings?

A few weeks ago, I picked up a 1BYC WABCO compressor. The tank is also WABCO and the motor is 1.5hp 115/230 GE.

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The photo of the new rings is of the 1BYC pistons, but the rings for my WABCO 2avc/LeRoi 400. The rings at quick glance, seem like the same material for both compressor rebuild kits. The 400 had a sheet with end gaps, but no luck for the little guy.

For the 400, I have a rebuild manual with all the specs, but only have diagrams and part numbers for the 1BYC with no ring specs or torque specs for the bolts (they are all 3/8"x16).

I haven't yet compared the numbers from the 400 rebuild kit to the manual. The manual has number for the smaller LeRoi units, but it doesn't list bore size, so I would have to hunt down specs for a LeRoi 100 or 200 and see if it is a similar size pump to the BYC.

The cylinder diameter for the BYC is 1-7/8" and 3-1/2".


Any suggestions for proper compression and oil ring gap?


There are plenty of pictures of my rebuild so far, so if people want to see more, I will post and add a little write up. It was one dirty machine but after cleaning up the pump, it looks like it is in good shape.

 

[CGT80]

After looking at the instruction sheet for the rings to the 2AVC, it does not list ring gap. The manual shows 7-17 thousandths for the 2.25" HP piston and 13-23 thousandths for the 4.5" LP piston. That works out to 3.11 and 2.89 thousandths per inch and 3 on average. This is for the compressor that I am NOT yet working on.


For the 1BYC, I wasn't able to find specs.

The new rings have almost no gap for the HP and will need ground. The oil ring is one piece.

The new oil rings (multiple rings and a wiper) for the LP have 36+ thousandths clearance in the unhoned cylinder and the top and mid rings 16 and 19 thousandths gap.

Old rings in this machine for HP are 17 and 19 for top and mid with oil at 34 thousandths. The LP are 22 and 23 for top and mid with oil at 33 thousandths.

The cylinders are not too bad looking and I have a couple 3 stone spring loaded hones to deglaze them. It was not worth buying locking hones. Those new rings for the LP have quite a gap and after the hone will have a little tighter fit than the old rings, but not nearly as tight as the machine I have specs for or the 1-2 thousandths per inch that I have seen posted around the forums (is 1-2 thou per inch even correct?).

Hopefully some people here will have input. Next week, I could contact the parts supplier and see if they have a recommendation.

 

[CGT80]

Does anyone have ring gap specs for any other cast iron cylinder air compressors?

I know a few people have rebuilt quincy compressors. The cylinder size and ring gap specs would give me a guideline to go by.

Thanks

 

[Packard V8]

That works out to 3.11 and 2.89 thousandths per inch and 3 on average. This is for the compressor that I am NOT yet working on.

Maybe overthinking this? If .003" per inch works for that one, why not for this one?

jack vines

 

[CGT80]

Maybe overthinking this? If .003" per inch works for that one, why not for this one?

jack vines

With almost the same design for both, I agree with you. I just need to pick a number that will work. Too much gap and it will have blow by, too little and worst case a seized piston.


If I follow that thinking, the new rings for the LP cylinder already have too much gap and the old rings were setup with too much gap, or have worn a lot.

Thanks for the input.

 

[MacMcMacmac]

Did you mic the bores? They could just be worn out. That thing is older than Methuselah's jock strap.

We always used 0.002" per inch of bore when we put in new rings.

Might be an off chance that LeRoi cylinders would bolt up.

Does this have the plunger oil pump on the crankshaft, and the shims to set big end clearance? Some of these old Westinghouse compressors used bearings poured right into the big ends and the clearance was set with a shim.

 

[Garciaibc]

Hi,

I'm in the process of rebuilding Westinghouse 1BYC compressor as well and I was hoping you could share your knowledge with me. Do you have the parts/ specification manual for this model? I've disassembled the unit and have taken all of the measurements, which I can share with all of you. I'm new to the site and all of the help would greatly be appreciated.

Thank,
Alex

 

[Mikeinmo72]

I just picked up a westinghouse 2yc compressor and i removed the unloader tube and the vent tube because they had been painted and a check ball fell out and I'm not sure which tube it came out of.... Any help is appreciated.. Not well versed in compressors... Thanks