Oh I'm going to test it just to see if it pops!
Old compressor - worth it to rebuild?
- Thread starter Aaron2
- Start date
MacMcMacmac
Well-known member
A 432 is as fine of a compressor as there ever was. Well worth rebuilding if you can get the parts cheap enough. Good for a 7.5hp motor and good to 200psi easily. The bigger 445 was good to 300 psi at reduced rpm. Check for wear in the wrispin bore of the smaller pistons since a hard pin in a hard piston was prone to wearing both. The bottom end is indestructible if there is oil in it.
Maybe cut a rectangular hole in it, install a glass plate, and try to convert it to a sandblaster cabinet? Or cut it in half and have some large solvent dip tanks. Definitely reuse it for something cool.
I actually got this based on a previous rebuild I saw on here. It certainly seems like a very capable pump, it's just a matter of hunting the parts. Everything seems mighty expensive for it!
Packard V8
Well-known member
Measure the piston bores and the ring widths. I rebuilt a compressor using rings from a Isuzu diesel. Four cylinder ring set was less than one new ring set from the manufacturer.
jack vines
jack vines
Thanks Jack. That thought had occurred to me. I imagine that the 3.25 bore can't be that rare a thing and surely other compressors used these pistons. Where did you find piston and ring sizes to compare?
Positive update this time. The crankshaft is perfect. The bearings are good and smooth. Measuring the rusty bore shows it to be around two thousand under in one spot but good elsewhere. I'm not sure how to proceed based on that but I'm talking to my machinist buddy about sleeving. The other three bores are perfect. Oh how I wish the dude had covered it better.
Attachments
finn
Well-known member
Clean the pistons and check for groove wear. With the rings stuck that bad, there’s a good chance there’s excessive side wear on the grooves, allowing oil to pas. The oil eventually builds up carbon and sticks the ring.
Yeah I imagined I was stuck getting new lp pistons. Didn't seem right they were sealed in like that. I'm not sure what the clearance in the groove should be. Tiny I'd bet.
chris142
Well-known member
Yard art.
There doesn't seem to be any clearance between ring and groove. Measuring them says maybe a half thou difference and that could be tool quality.
Yeah I'm getting a lot of that on this one. I have done some gnarly rebuilds before on tractors but the parts are easier to come by.
MacMcMacmac
Well-known member
My heart says rebuild it and enjoy. My head says it's probably a better idea to part it out. I'm seeing over $500 US for an overhaul kit, then add in the resleeving and finding a new tank. It might be worth it if you had a ready supply used parts.
A DeVilbiss 44642 is half of a 432 and used all of the same bearings, rods, rings and valves.
A DeVilbiss 44642 is half of a 432 and used all of the same bearings, rods, rings and valves.
acer66
Well-known member
Yeah the tanke begs to be repurposed if it does not check out.
Packard V8
Well-known member
Run that piston through an electrostatic cleaner and it will be good to go.There doesn't seem to be any clearance between ring and groove. Measuring them says maybe a half thou difference and that could be tool quality.
I checked the Hastings catalog and didn't find a ring interchange; 5/16" is not an automotive ring thickness.
jack vines
Last edited:
FJ 432
Well-known member
I would cut a hole in the tank and make it a fire pit.
isb cornbinder
Well-known member
One of my ancient hit and miss engines uses the same piston rings as a Ford Model "A".
Hey jack I think it's a 3/16 ring. I did find them for some old motors. .185 is 2.96 16ths by my reckoning.
It does have a hand hole. I think I could fit my phone in there to have a look around
weedy64
Member
Hey jack I think it's a 3/16 ring. I did find them for some old motors. .185 is 2.96 16ths by my reckoning.
3/16 (.187) could get the piston grooves enlarged
Call a piston ring tech line and see what they can do for you. You could fit 3/16 by enlarging the piston grooves on a lathe or use narrower rings and support rails.
Compressor pistons can be $$$ since the market is small, I had to ditch a GD compressor rebuild because the piston was 1k$. If you have to bore to fix...a Continental F226 piston is 3-5/16 3rings and an oil control if comp height is right, you machinist pal might be needed
3/16 (.187) could get the piston grooves enlarged
I'd save pump and the motor works! I'd ditch the tank, get the shape and size you want.
Call a piston ring tech line and see what they can do for you. You could fit 3/16 by enlarging the piston grooves on a lathe or use narrower rings and support rails.
Compressor pistons can be $$$ since the market is small, I had to ditch a GD compressor rebuild because the piston was 1k$. If you have to bore to fix...a Continental F226 piston is 3-5/16 3rings and an oil control if comp height is right, you machinist pal might be needed