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Discussion Starter #1
Bought an 80Gal. 5HP 3 phase Kellogg American air compressor that used their 335TVX pump from craigslist. Fellow seemed nice enough but was in a hurry so we just ran the tank up to 125PSI to see if everything ran and held pressure. I small talked for about 5 minutes - No apparent problem at this stage. It's a mighty big machine for an 70 year old to be muscling around so I decided to handle it by dismantling into parts - motor, compressor, and tank. Took my time and loaded and transported without issues.

Reassembled and fired off the machine to check that my phase wiring turned the compressor in the correct direction - no apparent problems. Went to perform a "final" adjustment on the belt alignment by moving the large pulley on the compressor - Hello Huston!

I rocked the pulley back and forth while I was pulling the pulley into final position and heard a heart stopping noise coming from the cylinders. Not just a scraping sound but a huge metal against metal gouging sound that persists for the major portion of the up stroke.

I've play with more than few motors and pumps along the way but never anything like this before. What bothers me most is that I know I knew better than to buy a piece of used rotating machinery without rocking quills and shafts!

Now the purpose of the post:
1) remind potiental buyers to ALWAYS disconnect power and rock compressor pulley, by hand, and listen for "foriegn" sounds. Air suction and exhust normal, scrapping/gouging not normal. You should not even hear the rings against the cylinder walls.

2) Normally, I would just start pulling the pump apart to investigate, But this time I thought I'd pause the action and ask the forum if anyone is aware of similar situations and what to look for.

I suspect a broken rod.

Regards to all,
- Dan
 

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i'm almost thinking that maybe a piston pin is working its way loose inside there. sorry your purchase didn't turn out so well but welcome to PEF.
 

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Was it still pumping air when you were checking rotation? Can;t imagine it would have made it up to pressure with a rod broke? Maybe what TN said and you put side thrust on the Rod/piston pin. Or maybe the shaft moved out enough to put it out of align with the cylinder?:eek:
And Welcome to PEF!
 

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welcome to PEF

wish i was more help but i just dont know without being there and hearing it :mad:

but keep us posted of the project and snap some pics if you can, help others in the future out
 

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Discussion Starter #5
Thanks Gang

I never thought of the pin itself working out. I'll disasemble carefully to see what I can find. I have the usual exploded parts diagram as a guide and the helpful data here and at About air compressors. but if anyone is aware of a good ordered sequence of compressor disassembly & rebuild I sure would appreciate a link.

I think I'll take photos and describe what,s happening along the way. Will advise.

Thanks Agin to ALL
-dan
 

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Discussion Starter #7
Roadlizard7,
This is a terrific manual. The use of a seperate blow out view by section, really makes following the equipment assembly straight forward, as well as it does for understanding interactions between groups. You have no idea how timely and helpful this post is. Still had it on the bench but in a "back burner status" as I was off handling other issues.
It will see good use! And, Thanks for a lead to LaPlante. I don't recall seeing their name showing up when I was exploring 335 sources with Goggle.
Thanks Again, - Dan
 

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I just wanted to add to this thread...

I worked for a hot rod builder a few years ago that had an old compressor sitting out in the elements... long story short, he gave it to me saying it was a good unit, but needed a rebuild.

After investigating, it seems it is a Kellog America unit with pump model 335TVX and a Chicago Electric 3hp motor. I was told it was originally a gas powered configuration, but at some point was switched to electric.

I am opening my own hot rod and VW shop, and wish to have a compressor with at least 25 cfm in order to adequately run auto body tools and paint guns.

Basically... need to know if investing in rebuilding this pump is worth the time and expense, and whether 3hp is even enough to generate the air I need from this pump. The link to the pdf diagram was helpful, as it seems the pump needs 800 - 1000 rpm to generate the desired cfm.

anyways... thanks for the info.

Derek.

www.facebook.com/the.dub.lab
 

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Discussion Starter #10
RE:

Volksgroove,

As a general rule you can only count on 4 PSI per HP. The 335TVX is not going to get you the 25 cfm you are looking for. 7.5 HP will get you there but you'll have put a comressor rated for 7.5HP which the 335 is not.

The 335 is good old fashion iron and will take alot, but like any of them there's just a fixed number hours available and they need a rebuild. Putting oversize rings on is certainly cheaper then a new rig but ultimately you only bump sizes but few times. Some guys rebuild many times, I get uncomfortable with the wall after doing it twice - thats just me.

It all depends on what shape it's in at the present time and cost rebuild vs hours bought with the overhaul - a gamble always.
- Dan
 
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