If its a three phase motor, it probably won't be worth fooling with, by the time you swap motors you would be ahead to get a running up to date unit.
If you want to find out more about this, go to
http://www.ytmag.com/toolt/wwwboard1.html and post a message. put "IR 321 compressor" in the subject line and hopefully XRogerX will see it and give you some answers. He knows all of the older compressors well and I recall him discussing a 321 sometime in the past
Virtually all of the "321 compressor" discussion centers about the Kellog-American unit. I wonder if the compressor has had the pump replaced with a K-A unit or IR used K-A pumps on some models?
Here is what I found that he had to say about the 321 in the past.....
Hard to believe, but the 321 is indeed a 1 1/2 hp compressor. These days, it would probably be running at 1500 RPM and be sold as a 5hp. Any good, non detergent oil will work fine in this compressor. 20-30 weight is good. You should be able to buy an aftermarket filter assembly from any local compressor supply shop. You can get them with 3/4" NPT fittings, so they will screw right into the head with no modifications. The oil level should be up to the bottom of the threads in the oil filler hole. If you can unscrew the sight glass, remove it and clean it. Enjoy your "new" compressor. It is of a far, FAR higher quality than anything you will buy new. Parts may still be available from CompAir."
In reference to a post mentioning a Kellog-American 321 and 335 that the post'er owned, inherited from his father a K-A employee (IR 321 is apparently a K-A pump)
"They were very good pumps. Depending on condition, I'd say they'd be worth a few hundred dollars at least. Don't know what they were worth new, but probably over $1000. CompAir has dropped all the Kellogg cast-iron recips. Looks like more Kellogg workers have hit the unemployment line since your dad did. CompAir now sells just German recips, Mahle I think, and a **** aluminum pump from Italy made by Balma."
Another post replying to someone with 321 problems.
"Go to your nearest compressor shop and ask them to order a head overhaul kit for a Kellogg 321 from ICC (Independent Components Corp) in New York. Or, you could ring these guys, depending on where you are."
http://www.aircompeq.com/ka.htm
"Kellogg used to make a model 321 which was pretty big for its rating"
One last thing...............................
"All the Kelloggs I have worked on have been pretty straight forward machines. Maybe someone has plumbed it in wrong or has a pipe screwed into the intake for a remote air filter. It may be a two stage machine which could be confusing you somewhat. The first (larger) cylinder, takes in atmospheric air and pumps it through an interstage tube (the finned one behined the flywheel) into the second (smaller) cylinder. Most Kelloggs have their air filters on top of the head or at the rear opposite end to the flywheel. Which model is it? (352, 452, 462, 123, 335, 340 ??) If it has a tag that says American Brake Shoe Company, it is very old. They have been owned by CompAir for many years. Be careful when dissassembling or reassembling Kelloggs. For some reason, the cast iron they are built with strips its threads like it's made out of cheese. This is especially critical if the back of the crankcase is split so the crank and rods can be inserted through the back as an assembled unit (most smaller Kelloggs are like this). They are very prone to breaking here and are scrap if they are, unless you can weld it up and re-tap it (not cheap). They have a centrally mounted oiler ring on the crankshaft (like a real DeVilbiss) so be very careful when removing it so you dont bend it. It has to be gently twisted sideways and lifted out of its retainer which is cast into the bottom of the crankcase. The crankshaft rides on tapered roller bearings and must be shimmed for proper end play when being assembled. Many, if not all Kelloggs use needle bearings on the high pressure wrist pin and so avoid the common problem of worn bushings, pins and pistons common to many brands of compressors. Make sure the little brass blow down valve on the back of the case is working if it has one. Make sure you put in a 60 psi safety valve in the interstage. This will blow if you have valve trouble. If the valves clamp into the head with a retainer, make sure you torque the bolts down evenly so you don't break the retainers. Kelloggs are long lived, excellent, durable machines. Don't use motor oil in it. You can probably buy a rebuild kit for it from any compressor shop, who will probably have to order it in from ICC out of New York (aftermarket parts)."
Not sure if any of this is of use, best to post and see what he has to say.
Charles
