[biscuit]

it's funny. the other day i was thinking i would like to build a gas powered air compressor. i figured i could use any electric one with a belt. and low and behold i found one on the side of the road. i figured the elec motor was bad. i brought it home, plugged it in and it works fine. went thru about 4 cycles of filling it with air and using a blow gun to empty it. it's a sears/craftsman 1hp. but i already have an elec one. so i am gonna sacrifice this one to build a gas one. now the search is on for a sideshaft engine. does anyone have any suggestions on what equipment i might find that has one? i live in the northeast. so we have all kinds of equipment kicking around at times.

 

[Tractor-Holic]

Snowblower,tiller,or edger will have a horizontal shaft engine,that will work as long as its 2,5 hp or greater,a 5-8 hp is better...be aware you'll have to re-place the valve that allows the compressor to shut off once it gets to maximum pressure to one that allows the gas engine to "free wheel" instead,and bleeds off compressor head pressure to allow the engine to be started with pressure still in the tank..a "Load Genie" is one such valve,sold by W.W.Grainger ,part #5x709 is one that will work,costs about 40-50 bucks..

 

[Kbeitz]

The valves are $$$$$

 

[saskman49]

It is called a governor/unloader
For gas engine compressors
Releases unused air for continuous running applications
Idles engine down when tank is full

 

[biscuit]

so that spring loaded valve that appears to be made of brass just above the adjustments for tank pressure won't work? i thought it was so the tank wouldnt overfill. hmmpf. ya learn something everyday.

 

[mbkerk]

I once had a gas engine powered compressor that would run wide open and just vent with the safety when it got full. It was by design.

Graingers has the unloader valve you will need, and the cable to hook up to it to idle the engine. If you have trouble searching it out, I will find it for you and post a link to it. Just point your search engine at Graingers.

 

[Kbeitz]

Ypu will change your mind when you see the cost...

 

[Tractor-Holic]

I dont know what they cost today,but my 1995 catalog lists the smaller valve like he'd need at $36.95...that'll handle 20 CFM....the BIG one I'd have needed to make my 7.5 HP 3 phase compressor gas powered with a 25 HP Onan,would need the larger one,rated at 125 CFM,that costed $151.50 back then...I bolted the electric motor back on and sold it after seeing the cost!..

Unless you find a blown up gas powered one in a scrapyard you can scrounge the valving off of,I think your better off leaving it electric..I have a 2 cylinder Bendix compressor off a Mack truck engine that ran the air brakes,it has a valve like the one we're talking about..the only reason I am not already using it is the fact the compressor used tp bolt right to the Mack's engine and had pressure fed bearings that were tapped into the oil pump on the truck--so to use it I'd need to invent a base,and some way to pump oil to the bearings..maybe the valve off a compressor like that could be adapted,I'm not much of an expert on plumbing them up though..

I had the Onan on my compressor,it labored a great deal to pump it up to 125 psi,and once it did and the safety pop off opened,it would wind up to 3,000 rpms,then it would just about stall once the pressure fell and it started pumping again..and if I shut it off with any pressure in the tank,even with a check valve between the pump and tank,the starter couldn't turn the engine over,too much resistance..to plumb it up right would cost 300+ bucks and I didn't need it THAT bad!...

 

[biscuit]

I once had a gas engine powered compressor that would run wide open and just vent with the safety when it got full. It was by design.

and did you have any problems with it?

 

[mbkerk]

and did you have any problems with it?

Nope... It was a low end model. Not real fast, but very portable. Had a 3.5 HP Briggs on it. It would pump up to about 120 PSI and then just spit and spit if you didn't use air fast enough.

 

[attorney_barnabas_collins]

I was wondering awhile back why you couldn't use an electric clutch off a lawn tractor and use some sort of off/on switch like the electrics already have?

 

[NSBolens]

Ypu will change your mind when you see the cost...

I can get one tomorrow for $80. doesn't seem too bad.

http://www.princessauto.com/air/pum...compressor-governor/unloader?keyword=unloader

 

[mechanicojoe]

sounds like a good project!

 

[biscuit]

well my weekend's pretty full, but i found a snowblower with a donor engine. not sure what size engine, yet, cuz i only saw it on the hill. gotta take the walk to go get it, but free is for me. so it's lookin like monday mornin will be the day. and who knows, maybe i can use the transmission for something. never any wasted parts around here. i will take pics and try to do a blow by blow description.

 

[xj35s]

This is very simple. Use the pressure switch to cycle an electric clutch on and off. It will work. I used an AC pump on my Jeep to fill a custom bumper to 150 psi. The the presure switch opened and the AC clutch went to neutral. Pressure dropped to 90 psi and it kicked back on.

On your engine you'll need to use power from the magneto to the pressure switch then wire the pressure switch to the clutch. Even better would be to add a small 12v battery. I found a small one at advanced auto for my ultralight that weighs 3 lbs intended for a personal water craft.

Tie into the same power wire to the clutch to run an auto lock solenoid to control the throtle. A trunk lid release solenoid is one way and would work great. clutch on/throttle on.

I ran my AC pump as an air compressor for many years. I only had an on/off switch on the dash. The first year it ran and used the pressure release valve to regulate the max psi in the bumper(150). Then I found a large junk compressor at the scrap yard and took the pressure regulator off that. It was factory set at 90/150. Impact gun loved it :thThumbsU

You could also use an AC from an early dodge van(1980's). They had a nice small vtwin cylinder with an oil filled crankcase. These are capable of building in excess of 400 PSI so be careful and make certain there's a relief valve.

 

[biscuit]

i'm gettin the donor snow blower today. my buddy came over and saw the elec air comp and was like "does it run?" then i showed him and told him i was gettin the snow blower that worked also. he said he thought i was crazy for "wrecking" 2 good machines. then i showed him the John Deere snow blower and the 220v air compressor in the shop. he asked my why i was building the gas powered comp and i told him "cuz i can". he asked me what i was gonna do with it. i figured it would be great in bone yard situations and when we go out wheeling. the first time he needs compressed air where there's no electricity, he'll understand.
now i'm just gonna have to figure out what i can do with thew rest of the snow blower parts. hmmmmmmmmm

 

[Tractor-Holic]

Why not combine both and have the worlds first snowblower/air compressor that's gas powered,self propelled and completely portable!..then your buddy cant whine about you "wrecking" two perfectly good machines!..

Dont you love it when someone says things like that??..

I get that a lot.."wyd'ya wreck that,it was a nice (whatever)..so encouraging,aren't they??..
I tell them I got the "donors" free,saved them from a crusher or dump,and why NOT make something else from them,especially if they are "non repairable" to be used as originally intended!..

I once got a mini-bike frame given to me,no motor or wheels,just the "bones"..it was someones home built "chopper" they gave up on,the front fork was raked too much and you couldn't steer it,cool as it looked,it was a POS and couldn't be ridden,after I got it all assembled and running with parts and an engine I had hanging around..so I decided to carve it up,and make a trike out of it instead..

Just after I'd cut in up with a saws-all,my friend pulls in and says AWW,man..WHY did you do THAT??..that thing was COOL!..why did you WRECK it??..

I told him it sucked,you couldn't drive the stupid thing,so I wanted to make it into a 3 wheeler..and he said "You must be whacked,you coulda sold that thing for 150 bucks I bet,easily"..I said no one I showed it too made an offer over 50 bucks,and I felt the 6 HP engine on it was worth that alone..and it was MINE to do as I pleased with it..so shaddupp!..

After a few weeks of tinkering, I assembled the remains into a 3 wheeled trike,using an old craftsman sit down riding mower's rear half of the chassis, chain drive rear axle and its 5 speed tranny,and the mni-bike's front fork and partial frame..welded it all together,now I had a 5 speed with reverse
3 wheeler, I could go 35 mph with in 5th gear,and use 1st gear to climb steep hills at 10 mph wide open..I used the centrifical clutch, and used a jack shaft to speed up the input to the tranny, so it would not crawl like a tractor in all 5 speeds...

I drove it around most of the summer,then someone driving by offered me 200 bucks for it,and I reluctantly sold it to them..been wanting to build another one ever since..got all the parts too,just aint enough hours in a day..
My "friend" was impressed with the 3 wheeler,and couldn't belive I sold it for that much..(he offered me 100 bucks for it after he rode it the first time,but I wouldn't sell it to him!..my way of saying "bite me" for saying I "wrecked" what I made it out of!..)

 

[biscuit]

ok there's been a slight revision to the "Gas powered air compressor" saga. i never got the snow blower because i got a hold of a 6.5 hp go-cart engine. it's red like a honda but the name is Dangjong or dangjingon or whatever. i got the engine for $25. it starts 1st pull and is quiet as a mouse. it even came with the centrifugal clutch that i can use on something else. all i have to do now is run down to the local Tractor Supply Co. and get the right size pulley to fit the shaft and i'm in business. i had to reroute the intake line and the guage package to fit the engine, but it should work sweet. i will be posting some pics. i'm going to equip this baby with some wheels to make trips to the boneyard a little easier. i'm even going to post a small vid of it running. wish me luck.

 

[biscuit]

ok so here's the final revision to the gas powered air compressor saga. i gave the engine to my buddy to put on his roto-tiller. now that thing goes like a ***** ape!! plus i get free fresh veggies. mmmmmmm.........

 

[Kbeitz]

The cheaper unloader valves wont work because they control the valves in the compressor head... If you system was electric is wont have that option...
There is a more expensive unit that doesent need the head option...