Quincy 240 ROC 8 piston

[Tinker Man]

I have a 1958 Quincy 240 8 air compressor and I need one 4 inch std piston pn: 1275-001 (this pn may have been superseded). One lan between the two top compression rings fractured an inch off. I suppose that is the reason I don't like aluminum pistons in a low rpm engine. In her youth I was told this old girl use to help get air start diesels going on tugboats.

I've checked several sites on line and all seem to be overly proud of their pistons, $200 to $260 for a piston seems steep to me. Many won't sell the piston without the rings and wrist pin which I already have new.

The above PN was obtained from PacficAirCompressors.com (also you might find parts manuals there too). I was told this is a Singlact piston. I've been told Atlas 113341 or 2024-4060-01 may be a substitute. Being a novice at this particular rebuild I need some expert advice.

If someone will point me in a direction where I might find this piston at a reasonable price I sure would be grateful. And if you are ever in my area I'll treat you to the best cup of Irish coffee you ever tasted. Ken

 

[Tinker Man]

I can tell by the silence no one, including me, knows where to get these pistons at reasonable prices. I've checked all the machine shops in my area except one which I'm going to check this afternoon.

I know I've seen these 3 compression ring + and oil ring pistons before, that was years ago, and they were being installed farm tractors. Yep... I checked there first.

I'm still spinning my wheels and going in circles.

 

[zkling]

Call Quincy for starters, in my experience they have been very helpful.
Then call your local Quincy dealer(s). I used to have a 230 or 240, they aren't very common and a bear to find info on. If you want to try and use another make of piston, you are going to need some good dimensions to go from as a reference.

 

[930dreamer]

Have you called here?

http://www.compressorparts.com/quincy-model-240-rebuild-kit-replacement-quincy-240-rk

 

[Tinker Man]

Fellows thanks for the responses. When, if, I get some good info on parts I post it.

 

[A_Pmech]

I feel your pain. I'm in need of a pair of Quincy 5846-001 pistons. Quincy wants $190 each and two weeks. Grr!

If you find a smoking deal on some Quincy 5120 high pressure pistons in your research, I could use two of them.

 

[Tinker Man]

A_Pmech , I suspect they aren't machining them until they get orders, hence the 2 week lead time. I've been told that some Atlas Capco pistons are interchangeable. I did find a sub number from them which I am also trying to track down. If I find something worthwhile I'll let you know.

A racing engine builder told me yesterday the reason for the high price is very few on the shelves and suppliers have us by the throats. He also said some of it is the 3 compression rings plus an oil ring is not common, except in the industrial arena.

Right now I'm waiting for compressorparts.com to get back to me. They sent me a preliminary reply yesterday. Ken

 

[A_Pmech]

Good deal. I decided to repair mine and I'm waiting on Summit to send me some BBC piston pins.

I think you're probably right on the stock issue.

 

[Tinker Man]

A Pmech glad to hear you found some parts so you can rebuild. Are the wrist pins over sized or std? If over sized will you need to replace bushings or machine the piston holes? This is the first time I've done a project on an air compressor so I'm interested in learning all I can.

I just talked with a machine shop that is drilling out a broken bolt for me. I had drilled this 7/16's bolt out, and was tapping new threads and my spanking brand new tape broke. I used the tap exactly as instructed, cutting oil, half a turn then back out clean the threads, etc., and it still broke. I suspect it may have had a flaw in the shaft.
I told the tech about the problems getting a piston at a reasonable price. He told me to bring my old piston to him in the morning so he could look at it. He said if it is nothing out of the ordinary he would make me one. If he is going to make it out of steel, I'm going to have him make me two of them... then my compressor will be truly industrial grade.

I also have a 325 roc 7 that I want to rebuild... and it needs both the 2.5 and 4.5 inch pistons. The HP side just wore out at the wrist pin and the LP side galled the piston skirt.

I've come to the conclusion... I need them to work and it's only money, and I can't take it with me.

I'll let you know about the price on the custom made if he can make it for me. Ken

 

[A_Pmech]

Ken,

I'll be using oversized wrist pins from a big block Chevy. The pins that came out of the compressor are about .875" dia. The new pins are .990" dia, so I'll be boring the pistons to suit.

I considered making a set of high pressure pistons before I settled on repairing the existing ones.

Unfortunately, a new piston is the best fix for a broken ring land.

You can see the repair here: http://www.garagejournal.com/forum/showthread.php?t=106289&page=14