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Quincy 325

Jared

Aluminum
Joined
Jan 17, 2006
Location
Portland, OR
A friend and i recently came into possession of a Quincy 325 ROC 10. It sounded like it had some rod knock and didnt seem to have been well taken care of so I thought it best to do a rebuild. I've done some minor rebuild stuff with some gas motors but never anything real serious and i certainly have never dealt with an air compressor. i ordered the rebuild kit from Here and have torn a good bit of it apart already. the only major damage i have seen is a broken bolt holding an exhaust valve assembly together.

Does anyone have any suggestions on rebuilding one of these or any air compressor?

Does Quincy offer a rebuild manual with torque specs and the like? Will they be able to help with parts that i can't source elsewhere?

Thanks for your help.
 
My company is a Quincy distributor, and our service techs also work on all Quincy units. From my experience out on the field, many things can cause a rod knock that you may not be familiar with if you have no air compressor experience. precisionworks is absolutely correct in what he wrote above. I would call Quincy, and they will send you to your local Quincy distributor. What our company will do from time to time is actually give you a newly rebuilt pump in exchange for the broken/noisy pump. This way, you get a faster turn around on the rebuild, and our shops can thoroughly examine the knocking pump to ensure there is no cylinder/pin/ring/bore damage, along with replacing the common rebuild spare parts.
 
What our company will do from time to time is actually give you a newly rebuilt pump in exchange for the broken/noisy pump
Did you say "give"? I ask because my experience buying quincy parts has never struck me as a giving one. :D
 
I looked around on quincy's site for a local distributor and sure enough there happens to be one about 10 minutes away. hopefully i can pay them a visit soon.
 
Jared,

Overhauling a small compressor pump is basically very similar to overhauling a Wisconsin or similar small engine. The principles are pretty much the same as working on any engine, for that matter.

There are three likely causes of a knock in a compressor pump, which usually track back to use of the wrong oil, failure to change the oil periodically, or oil leakage til the pump runs dry. The three common knocks are a rod bearing failure, gudgeon-pin bushes, or the pin-bore in the piston, wearing loose, or a build-up of carbon on the piston-tops.

The combination of worn rings and low-quality or deteriorated oil will cause dramatic carboning-up of the pump......I remember one Quincy which was neglected til the entire head and valve cage assemblies were solidly choked with carbon build-up.....it would run, but didn't move much air.

A rod bearing failure from bad oil or no oil is obvious, same as any engine.

Call the works for a specs/parts sheet, and ask for a set of assembly drawings.

Clean the exterior of the unit, and work in a clean location.

When disassembling, mark adjacent parts with matching number stamps. Note the lengths of bolts/capscrews, and bag them, noting the places they came from. Bag and tag the parts as you remove them....take photos of the disassembly process if you like.

Look for wear spots on the parts as they come apart, and reason out whether those wear spots are 'normal wear' as compared to 'abnormal wear' on misaligned parts or parts which came adrift with the machine running.

Match-mark the low pressure rod/cap, if it isn't marked already, pull the cap off, and remove the piston/rod assy.

Likewise, mark the high pressure rod/cap, have the cap off, then remove the capscrews holding the cylinder casting to the crank-case, and remove the cylinder casting with the h.p. piston/rod assy.

Carefully inspect the 'crankpins' or rod journals on the crank-shaft. Look for any loss of the high finish original grind, such as noticeable wear or scoring.

If the crankpins are scored, or out of round as much as .001/0015, don't try to 'polish' the pins, send the crank out for re-grinding. Look in the 'Yellow Pages' for a specialist crank grinding shop in your area, or call a local Diesel engine shop and ask who they use.

Carefully inspect the pistons for scoring, ring groove wear, or other damage. Check the fit of the gudgeon-pins (wrist-pins) in the pistons....there should be no appreciable play. Sometimes, particularly on the h.p. piston, the pin bore will have worn oval....if so, replace the piston.

Inspect the cylinder bores for wear/out of roundness, per dwg specs. Have the cylinders re-bored and fit oversize pistons if necessary. I've gotten by with honing bores round/straight as much as .007-.008 over, and knurlising up the pistons to match, when oversize pistons weren't available, but I'm not recommending that you do that.

Any good automotive machine shop can fit the new bronze pin bearings in the rods, assemble the pistons to the rods, and check piston/rod alignment.

Have them hone the cylinder walls lightly to 'de-glaze', leaving a nice 'cross-hatch' pattern. Be sure to trial-fit the new rings in the bores, and adjust the ring-end gap if necessary, per assy dwg specs.

Its unlikely that the 'big ends' of the rods will need to be 'reconditioned' by grinding the caps a few thou and honing the big-end bores accurately round in the Sunnen hone, as is commonly done for engines.....but have them check the big-end bores, just to 'play safe'.

If the big-end bores show any damage, take the crank and the new bearing shells to the shop, so that they will be able to establish the correct i.d. for the big-end, for the correct bearing clearance.

Clean the the oil pump and all oilways carefully, using acetone or lacquer thinner, (put a small fan behind you to blow fumes away) and lint-free rags. Inspect the oil pump for worn or damaged parts, and fit new components as necessary.

Assemble the pump much as you would an engine, in a clean environment, using loctite on the threads and new capscrews or at least new lock-washers. Note the torque specs in the assy dwgs, particularly for the rod caps. Use a good grade of 'assembly lube' on the bearings.

Replacing the valve discs/springs per the drawings will be obvious.

After disassembling and cleaning the valve cages, lap the valve surfaces against which the discs bear, using 400, then 600, emery paper on a known good flat surface, such as a small granite surface plate (buy an inexpensive small granite 'toolmakers flat' for the job, if needs be)

Clean/gently polish the little pins for the unloader, and other unloader parts, as needed, so that they work freely....apply a little bit of 'assembly lube' at assembly.

When re-assembling the pump, leave the head assy off.....put the pump back on the tank, belt it up to the motor, fill it with best quality 'compressor oil', not 'motor oil', and run the headless pump for a few hours, as 'break-in' time.

After the 'break-in' run, drain the crank-case, refill with new compressor oil, put the head on, taking care to torque the head-bolts carefully, and run the pump to pressure, noting unloader operation and pressure switch operation. Re-torque the head-bolts, and snug up the bolts holding the valve cage retainers/unloaders.

Yes, I know, all that seems like a lot of work.....but its not a bad job, actually....much easier than any automotive engine.....

There's nothing whatever mysterious about rebuilding small compressor pumps.....just follow the works manual or assembly drawings exactly, keep everything perfectly clean, use ordinary common sense, and you'll do just fine.

cheers

Carla
 
Industrial Tech....

As chance would have it, I had a local mechanic ask me about rebuilding his compressor, just today....

He has a 5hp Speedaire, which is simply 'committing suicide' as those do, and I really don't feel like working on one of those.

The tank and motor for his compressor are fairly new, and good, so replacing that Speedaire pump with a 325 Quincy would be the obvious answer.....could you quote me on a factory rebuilt unit?

And.....I have a couple of little Quincy pumps here for rebuilding at the moment, a 216 and a 325, could you quote me on rebuild kits for those?

(the local Quincy dealer here has closed down, gone out of business)

cheers

Carla
 
Wow, thats amazing. i really apreciate you breaking it all down for me. i will see if i can get some of those drawings, seems to be just what im after.

I already have some compressor oil (mobil rarus 427, probabaly overkill)and a rebuild kit is on its way. now i just need to get that stinking front plate off and we will be set.
 
So i am having a few issues. I havnt had a chance to go chat with rogers machinery (the local quincy people) yet, mainly due to this whole weekend issue. but i am trying to finish disassembling the compresor and am running into two big issues.

1. I can not, for the life of me, get the cylinders off (the top half of the case) i beat on it, soak the seal with liquid wrench, beat on it some more. Doesnt budge at all. so far it seems ive taken all the fasteners out (6, two on each end and two in the middle) but i guess theres always a chance im missing some, or one.

2. the front (back i guess) plate thingy that holds the crank, and prevents me from taking the crank out.


If anyone has any thoughts on this, or anything else, please share.


Jared
 
Carla, I would be happy to quote you on the equipment you have requested. Before I do so, I have to be sure that the Quincy territory you are in is allowed to cross over with my business territory. Where abouts are you located? If you are not in a territory that I may qoute, I can certainly find out who in Quincy can offer you this. Either way, i can have a quote from myself or the correct person in less then a day of receipt of this information.
 
Hi, Jared,

If memory serves, the 325 Quincy has only six head-bolts, so, if you've removed the long bolts for the intercooler, and removed the six head-bolts, the head....in theory....is free.

If its 'stuck', you've run across a minor nuisance problem which is common in older compressors.

The gaskets used in the head-to-cylinder joint, cylinder-to-crankcase, and for the end-plates which carry the Timkens, are of a variety of highly compressed treated paper, a very dense, strong gasket material.

Over many years time, those gaskets evolve into a substance which is the effective equivalent of a strong industrial adhesive.

The only way to break the holding power of those gaskets is to literally split them. A good improvised tool for the purpose is a small number of 'Irwins', driven into the gasket line between the parts.

An 'Irwin', refers to the Irwin brand of screw drivers, which are forged with the handle area integral with the shank/blade, and have two pear-shaped wooden handle scales. Sharpen the screw driver tip to form a thin wedge, and simply drive a few of them, gently and uniformly, into the gasket line. This will split the gasket, and free the parts.

(obviously, lacking real 'Irwin' screw drivers, you can make suitable sharp wedge tools from any good make of screw driver.....just cut away the wooden or plastic handles, sharpen the tips, and you're ready to go....for the real purists amongst us, yes, the old 'Vlchek' steel handle screw drivers are even better than the Irwin make, for this purpose. Alternatively, use a pseudo-chisel made from a sharpened short scrap of power hack saw blade, then wedge with screw drivers)

Be careful when removing the end-plates which carry the Timkens. Those have a turned diameter which fits closely in bored diameters in the crank-case. (this is called a 'rebate' or 'rabbet' fit) Wedge carefully on all sides to split the gasket uniformly, then wedge the parts away from the crank-case uniformly on all sides, don't allow the part to become 'cocked' to one side, or it will jam.

Note the shims under the little plate on the flywheel side.....you'll need some new ones to set the end-play of the crank-shaft when you fit the new Timkens. (removing the old Timkens from the shaft is obvious, but do remember to use a suitable piece of soft metal protect the shaft from the puller screw)

Removing the remains of the gaskets from the castings without scratching up the machined or ground surfaces of the castings will require a bit of care. A very sharp woodworking chisel, used gently, with discretion and a bit of patience, will do nicely.

cheers

Carla
 
I realize this is a very old thread. I'm contemplating a rebuild on my Quincy model 325 pump, ROC 13, and I'm looking for someone who can tell me the actual Timken bearing numbers for the cones and shells used on the crankshaft of my pump.

I have the Quincy docs and they only cite internal part numbers. Nothing against Quincy but I've found on other expensive bearings (Bridgeport spindle bearings, KO Lee grinder spindle bearings) it pays to buy your bearings directly on ebay, even in its much-reduced current state.

Would appreciate replies either directly to this post or by email to gwe AT tinyisland DOT com because somehow with the proliferation of these-here message boards, I don't seem to notice I have private messages until months after I'm sent one, thanks!

metalmagpie
 
OK never mind - I figured out (DUH!!) that the Quincy numbers *are* the Timken numbers. In particular, for the 325/13:

2788 CONE - PULLEY SIDE TIMKEN BEARING
2720 CUP - PULLEY SIDE TIMKEN BEARING
2585 CONE - OPPOSITE PULLEY TIMKEN BEARING
2523 CUP - OPPOSITE PULLEY TIMKEN BEARING
 








 
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