Hey guys kind of an off the wall idea here. Let me what you think, if I can do it, what I need to get it done if I can. Ok!! I am wanting to try and build an air compressor out of an engine. I thought that if I take some pipe and put a T on each the end with check valve out & in. Using the engines compression to create a pump into a tank. I don't need any of the engine accessories just basically the block and internals to create a large pump. I am thinking I can us a lawnmower engine to turn the crank which in turn will create a pump. I know this sounds crazy. But if you guys can shed some light on the subject for me please let me know.

 

Sounds like fun, a few months back on junkyard wars they turned a big v8 into a waterpump. Maybe they will show the episode again and you can take notes?

-Jon

 

That'd be one hell of an air compressor. How bout a 460?. You'd have to keep the crankcase filled with oil and have a big check valve. It could be done with some creativity. Maybe weld a big pulley device to the flywheel or the crankshaft nose and have it be belt drive? or chain drive? Just make sure it's runnin in the right direction or it wont compress nothin. I reckon you'd need a big pulley on the compressor and a small one on the drive end. Hit that junkyard and find yourself some parts! :-X11

 

if you want to create a good air compressor from an engine block My uncle did this with a VW engine he put 20-50 oil in it to help keep things moving and he also used the VW engine because it was aircooled
he kept the VW fan in the back to keep air cooling the cylinders and it worked great. the only modifacation he made was an oil bath air filter and a 6 hp elctric motor to keep it moving to compress air. A VW engine is probably your best bet. Becuase even though you are not running gas threw the cast iron block it will still build up heat and sieze. The VW is very good at dispersing the heat evenly

 

I've seen it done with an air-cooled VW except it ran on two cylinders and the other two pumped the air. It was on a small trailer with a gas tank, air tank, battery and starter for a portable ~50 cfm compressed air source.

 

Why not use a V8 and run the engine on 4 cyls and use the other 4 cyls as your compressor. On a 2bbl, one half of the carb feeds the 2 end cyls on one bank and 2 centre cyls on the other bank. eg 1,4,6,7, could be used to run the engine. 2,3,5,8 would be your compressor. I'll leave the valving up to you.

 

There used to be an outfit that converted engines into air pumps for the vacuum truck industry for oil field use and sewer suckers, etc. As I recall the heads were changed to use engine intake and exhaust stroke to open the valves instead of using the cam. The exhaust valve was turned over so compression stroke would open it. You can use a lighter spring and pump air with each revolution that way. The whole thing was powered by the truck PTO. My grandfather also used to use an adaptor in place of a spark plug to inflate tires around the farm. Not too sure about the wisdom of using a theoretically explosive mixture in your tires, but it worked, although was rather slow.

 

>There used to be an outfit that converted engines into air
>pumps for the vacuum truck industry for oil field use and
>sewer suckers, etc. As I recall the heads were changed to
>use engine intake and exhaust stroke to open the valves
>instead of using the cam. The exhaust valve was turned over
>so compression stroke would open it.

So you'd actually be putting a valve seat on the inside of the exhast port? Or do you mean power stroke would open it?

You can use a lighter
>spring and pump air with each revolution that way. The whole
>thing was powered by the truck PTO.

You could also get a special cam made. Grind off the exhaust lobe and weld a lobe in the cam to open exhaust valves on power stroke. Then make some correct threaded pipes to fit in the spark plub holes and have them run into a common collector and to your air holding tank. You'd probably want to put an air filter on the end of you exhaust header to filter air and maybe even turn them upside down. Sucking air in on both power and intake stroke and compressing it on compression and exhaust stroke is the aim.
I suppose you could possibly remove the cam all together and use light spring in both the intake and exhaust valves and have them open like reed valves on power and intake strokes. Then still compress through the spark plug hole and home-made piping.
Just some thoughts. There's all kinds of things to try.
Tony

 

I believe they used a special head which utilized light springs on the valves so that the piston on the way down opened the intake and the exhaust was opened by the compression on the way up.

 

You would have to have the exhaust valve reversed in some way so the seat is toward the piston chamber. No way are you going to be able to have a valve spring hold the exhaust valve shut against pressure building up into the output(ie supply tank).
Say you have a 1.5 inch diameter exhaust valve. That would be 1.5 divided by 2 then squared times 3.14=approx 1.77 square inches of valve area.
If you wanted to develop 120 psi of air pressure, then the valve spring would have to be able to hold at least 120psi times 1.77si=212lbs of pressure. I just looked in my book at a 302 spring pressure as an example, and although the springs are rated at 250 lb/inch (350 for HP), the actual spring pressure exerted on the valve when it is closed is only about 57-96 lbs(96 is boss 302).


I would pull the head off completely, and make my own head out of say 1/2" steel with reed valves made into it or threaded holes for mounting some other kind of check valves.

 

ive seen this done. you have to run a differ intake that will give fuel and air to 1,4,5,8 and a differ distib to fire the cyl so it will be balance and run a fresh air intake for the other 4 cyl and put a check valve in the plug holes on them. the one i seen was on a truck. it worked pretty well

 

That makes sense. I wonder if they took the rocker arms off the exhaust valves on the compressor cylinders too.

 

hey guys
the compressor your thinking of is made by grimmer schmitt and I belive the last time I checked you could order the head from them for a 302 ford motor that what all compressors was the kit came with all the parts for change over

 

I toured the Jasper Engines facility a little while back and they showed us there air compressesor room, they had 4 460's somehow rigged up to do all the compressed air they could ever need (and thats a lot)

 

Why couldn't you just remove the lifters,pushrods and rocker arms from the compressing cylenders and install a light spring on the exhaust valve so it works like a poppet inlet and use check valves on the spark plug holes?The compresion would hold the exhaust valve closed and push the air out against the check valve,then on the next stroke the vacuum would open the the exhaust valve and so on.
The original intake valve spring would keep it's valve closed agianst any fuel from entering???????...stvsr1

1993 Ford F-150 4X4