Air compressor question

1. As I said, the original motor was replaced with a single phase 3 HP. I imagine because the original was 3 phase, and probably bigger. Never seen a compressor with a 80gal tank less than 5 HP. Would using a smaller motor be a problem? What if it's not running at the specified RPM, is that a problem?

2. The pump is all cast iron, a good thing from what I've gathered on this forum. Are they generally rebuildable (it was built in the USA)? More importantly, how can you tell if it's bad?

3. Oh, by the way, the asking price is $400. I'll have a chance to hook it up and see it work before I buy. Let's say it is a 2 stage, light commercial quality compressor, how long should it take to pump a 80gal tank from nothing to 175 lbs? Most of the new compressors I've researched (in this clas) should pump about 13-16 CFM at 175 lbs. Since the motor is smaller, I figure it should take about 20-30 percent more time to do it than a new 5hp, 2 stage, 80gal tank compressor. Anyone in the mood to discharge theirs to let me know?

Any suggestions on other things to check would be well received!

Mike
Chickamauga, GA

They're having trouble with blowing out the pvc pipes and keeping water out of their quality air tools. They said something about putting a 6 foot drop in every 6 inches or something like that to keep the water out. That sure sounds like alot of elbow fittings for no more good than the water pressure will be..

On the plus side I bet they don't have to use soap or even take off their clothes to get clean in the shower with that much pressure to burst pipes. I bet when somebody fires off a 3/4 inch impact from that setup while they're in the shower it cuts down the pressure alots tho.

Watchout on truck load capacity info too cause T_Bone hooks his trailer to the drivers side door post somehow to the vehicle data plate.

Just be careful with the pvc pipe maybe we can get somemore info before you get that far along.

$400 does'nt seem to high for a good American made compressor. I saw on ebay where somebody bid $2000 for some cigars of President Clinton's, and they don't even know if Monica used it or not.

2) Take a compression test or use the pressure gauge to maxmium psi at shut off. If it won't shut off then the compressor is worn. Sure there's always a way to rebuild a compressor. Is it cost effective is the answer.

3) I just bought a Ingersol Rand, 3hp, 60gal, 11.3cfm @ 135psi two stage, oil cooler, auto tank drain, auto low oil shut off, for $530 delivered from Northern Tools. How does it work? I can't tell you as it's still in it's packing create :) lol

If it's completely spotless like it has just been cleaned, could be hiding something wrong or a very neat person? I would rather see some dust and no oil leaks.

T_Bone

Great comments, thanks. Just to be sure I understand, the compressor will be fine with the wrong motor, but the motor may not. Makes sense. It doesn't have an adjustable sheave, but that's an easy fix. If the compressor then runs too slow, it'll still make it's rated psi, just not as fast?

As for condition, looks like it's never been cleaned, was in service outdoors but covered, and is generally quite good.

Later,

Mike

I would think a good 5hp ball bearing motor will cost $150

Let us know what you buy.

T_Bone