homemade air compressor

[Dan69GTX]

I've enjoyed reading what others have done so I figured I'd post another one of my creations.

I built this several years ago. I needed a lot of air for sand blasting but didn't have the funds for a large compressor...so I built one.

The donor vehicles were - an old trailer - for the frame and a 1983 Honda Civic - for the engine (compressor) and transmission. The modifications to the engine: Can't remove the cam because it drives the oil pump, so all rockers, etc were removed from the head and all oil passages welded shut. Remove the intake valve springs and replace with real light springs (the suction from the piston pulls air past the intake valves - in other words they just "float"). Remove spark plugs and replace with check valves brazed to "spark plug no foul" adapters. Remove carb and build adapter to take a GM air cleaner assy (much cheaper air filters than the Honda's). Add a hose to the heater tube on the head and attach to plastic antifreeze overflow container - this allows for expansion of antifreeze. The existing water pump circulates the water - no radiator needed. Weld an adapter to part of a rim to allow a PTO shaft to connect to it. The transmission is used to turn the compressor. I used the correct side to allow me to select gears 1-5 to best match compressor RPM to PTO speed for max air output. Too fast and the intake valve float too much and you loose efficiency.

The check valves are plumbed together and run into a "manifold" which goes through an air to air heat exchanger, which goes through a large check valve, which goes into the exit manifold that has a pop off valve (from an old boiler), pressure gauge, connection to tanks, ball valve (for drain) and quick connector. The radiator fans from the car are mounted over the heat exchanger to help with cooling.

The heat exchanger is from an old house water to air heat exchanger for a boiler unit.

The air tanks consist of a tank from an old air compressor and a 100 gal propane tank.

Everything is bolted together so anything can be removed/repaired.

It served me well for several years. Now it only gets used when I need portable air.

 

[teg]

I would like to say "That's the coolest thing I've seen for a while".

and tractor driven to boot!!!

PS. Nice trees in the back ground!

 

[Bird]

I'd say that's definitely one of a kind. Do you have any idea what volume of air it'll move?

 

[Dan69GTX]

No, I'm not sure how much it will move. As a guess I'd say only about what a commercial 5hp compressor puts out - or about 15CFM. It's capable of much more, but there is too much valve float at higher rpm.

Hindsight - I should have used the exhaust valves since they would be lighter - but that would mean I'd have to manufacture an intake manifold for the exhaust ports. I could remove the head and lighten the intake valves which would allow more RPM before they floated too much.

Or...

I could of had a V-8! Can't beat cubic inches. I do have a 318 I've thought about using, but I don't have a manual trans to attach to it. Direct drive would only give 540 rpm max - not enough.

 

[Grrrr]

That is a cool invention

Reminds me of something I saw on a Scrap Heap Challenge or Junkyard Wars (do you have these programs over the pond?) once. They were using an old engine to pump water.

There was also a tractor made once that had some of it's cylinders used for pumping air, I can't think of it's name. There was a recent thread about it here.

 

[tlbuser]

Yea, "junkyard wars" cool show. This compressor definitely could've come out of there.
Very creative use of spare parts.

What types of apples are you growing?

 

[6sunset6]

I have a Schramm compressor 1/2 restored. It is a 1947 using a 1940 ford flathead v8. The cam shaft is set up so 4 cylinders are engine and 4 cylinders compress. The engine manifolds are separate from the compression manifold. The compression cylinders compress on every stroke. I think it was rated at 100 cfm. Jackhammer compressor. It has the wierdest distributor with 2 sets of points. I have never set up anything like that but I have the manuals for the engine. Probably can figuire it out if I ever get that far.

 

[gizmo]

Innovative approach to a problem. I was curious about what kind of pressure you get since the compression ratio of a gas engine is much lower than that of a compressor.

 

[travis potter]

I like it. Gizma Should be same pressure as you get with a compression tester on the motor. would it work with intake and exaust valves as intake?

 

[Dan69GTX]

Junkyard wars - yes, I've seen that before. Don't remember where, but it did appear to be interesting.

The compressor easily builds to 125 PSI, which is where I have the pop off valve set. I was going to use a small air cylinder I have to disengage the clutch at a certain pressure, but it was much easier to just let it pump air back into the atmosphere.

One thing I did after these pics was to put a squirrel cage fan on it and blow air into the air cleaner. This worked to help increase it痴 efficiency. However I just used a regular motor so it needs to be plugged in to 120V.

Apples all sorts of apples around here. The ones in the pic are Golden delicious.