"new" Old Compressor Re-build

12bolts

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I have had this compressor kicking around my shed for some time now, (years) and I have decided to strip it and rebuild it. It was picked up at a clearing sale, and at the time I thought it was a 3 stage HP compressor. It also came with a bunch of stainless tubing and some manifolds and HP filters. Although it looks pretty sad, everything came apart reasonably easily, nothing seemed to be too badly corroded and the oil that I drained from the sump was reasonably clean.
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I havent found any manufacturers name on it, just a few casting numbers for covers etc. However I did discover that it is a well traveled compressor, having been overhauled in Georgia USA at some stage before winding up in Qld Australia. I havent as yet worked out what WRAM"?" means. The date is unclear and the year is not legible.
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One cylinder has a one piece, 2 diameter piston with rings on both sections. There are connection ports on the cylinder head above the large diameter piston, and connection ports midway up the cylinder barrel, to presumably take air from this smaller diameter section.
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The other cylinder has a 2 piece, 2 diameter piston that is bolted together. I think the upper piston is screwed to its pushrod, but I havent been able to separate this piston, completely yet so I am unsure exactly. There is a flange that was bolted to the top of the lower piston using 4 bolts, with 2 holes left open for air? oil mist? to pass through.
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The upper, small diameter piston has a solid conrod that bolts to the lower piston and as yet I have not been able to remove this piston from the cylinder/head. There is a "screwdriver" slot in the piston top, but I havent been able to turn it, and the lack of purchase on the lower flange/shaft, (which is very hard steel and polished) makes it difficult. There is also a captive ring that was retained by 6 cap head screws on the lower area of the upper cylinder, however because I cant remove the piston and pushrod from the cylinder I cant see its function.
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So far, in stripping it down, I have found that it has a gear driven oil pump with a screened pick up, and I think a relief valve. There is an external oil filter. Separate crank case breather. A number of, what seem to be pressure relief valves cast as part of the cylinders. The crankshaft is supported by tapered roller bearings at each end, with preload set by shims between the crankcase and the access port for assembling the crankshaft. White metal bearing shells on the conrods. Everything seems to have been lubricated correctly as it was free to turn, but one of the cylinders had some debris in it. No apparent scoring of the bore, so I think it may just have been dirt and dust from years of sitting idle.
It does now, seem to be a 4 stage compressor although I havent seen one in this configuration before.
One crankshaft roller bearing has some minor marks in the outer race, so I may replace them if I can source them, (havent measured them up yet) and the oil seals on the crankshaft will hopefully be readily replaced also. I have no idea of RPM, CFM or operating pressures. Any ex Air Force compressor mechanics out there? :eagerness:

Cheers Phil
 
Hi Phil
Cool old compressor. Looks like a neat project. I wonder if it was used on an airplane? Kind of like an air brake compressor on a highway tractor.
Cheers
Martin
 
? Catipiller brand?
 
Did a little research and it seems what you have is a hp (3000psi) compressor for producing breathing air. Couldn't find the exact unit, but it seems they were generally powered by by 3hp electric, or 5hp gas engine. Only spent a few minutes looking so a more refined search would probably get you some better info. I worked in Naval air ground support from 69 to 74, but mostly on hydraulic test units and turbine starting equipment. Are you planning on using it for shop air? Mike
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for pressurizing breathing tanks for aircraft ? maybe. . . .
 
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