SpudFiles

Would It be possible to convert a small 2-stroke pocket bike engine to run off of compressed air? I was just wondering what to do with my old engine...

you'd have to modify the piston head to knock open a valve when its at the top of its stroke, but yeah, it should be do-able.

those air-hog engines are pretty powerful...........

if you went out and bought like 20 of those and had them all geared down and powering your minibike, it would work......

you could also just examine how the air hogs engines work and manufacture your own out of plumbing parts. it should be doable.

JSR, I really like your idea, it seems simple enough
VH-man, do you have any idea what the cheapest airhog plane is?

Hmm. Im not sure, i know they sold a car one a while back.......

i gotta say, just go and look. theyre ususally about 20-40 bucks.......

if i find a diagram of the parts ill post-em
EDIT: i found them. it makes perfect sense. see if you cant manufacture that..... and runn it off HPA or something.
http://www.keveney.com/co2.html

If you make one, make sure that you post it!

I gotta say, i might even make one of these. they look pretty simple.

OOOO GOOD IDEA!!!!

the same mechanism could be used to make a semi-auto gun of some sort!!!!!!! yay. might have to try that. in fact, it could be full auto. just replace that little cam weight with a spring....... and a sear so you can actually stop it.........

If all else fails, you could get one of these:

http://surpluscenter.com/item.asp?UID=2 ... atname=air

.4 HP 10,000 RPM PNEUMATIC MOTOR
New, GAST model 1AM-NCC-104 pneumatic vane motor. Can be used in any orientation. Maximum ambient air temperature 250° F. Muffler included.

SPECIFICATIONS

* Max. 0.42 HP @ 7,750 RPM & 100 PSI max.
* Max. torque 5.4 lb.-in. @ 500 RPM & 100 PSI
* Max. 10,000 RPM @ max. air flow 21 CFM
* CCW Rotation
* Non-reversible
* 1/8" NPT ports
* 5/16" dia. x 2-1/4" long shaft
* Hub mount w/ 1-1/4" pilot and two 180° offset 1/4" dia. set screw points
* Size 2-3/16" x 3" long
* Shpg. 3 lbs.

you might want to gear that down a little bit.............. just a little...........

7,750 RPM is kinda fast..... and .42 hp will get you nowhere on a bike.

i honeslty reccomend making your own air-hogs style engine, with like 4 piston chambers. i take it you have expertise in building airtight piston valves, all it really is is a piston valve with a spike out the top that pushes open a valve. could even be a swing check valve for simplicity.......

and remember, dont put a muffler on the thing. you want it LOUUDD!

and then ppl ask (that things powered by air?)

i gotta say this is a revelation for me. mabey not for you but for me. god this makes me happy.........

Bike? If you are using one on a bike, you will probably need a huge air tank, or long air hose, or a 20+lb Co2 tank with high flow regulator. You could have the bike powered by a propeller.

i think he was aiming for something along those lines.......

i do know air hogs engines are VERY efficient with air. a 12 oz CO2 tank would proboably last about halph an hour with one of those store-bought engines, but then i dont know if they could take the pressure..........

I'm not going to power the pocket bike with it, i just wanna see it work

oh. well, that diagram i showed you should help. only thing im not clear on is how the piston moves foward without building up pressure in front of it that prematurely opens the valve..............

im thinking that mabey there is some kind of "pressure" valve that closes at around 50 PSI, but remains open at around 10. either that or a flow controller that closes when flow rate increases significantly........

I'm pretty sure it's just a check valve...

no, beause the pressure is always to one side of the piston, so a check valve would always be closed, and do nothing...........

EDIT: i had a brain fart. theres a reason why the little rubber seal on the piston goes (slap) when it opens the valve. i dont know how im going to recreate this, most likely ill do without it and hope that it still works......... for my airsoft rifle, that is.

for you, building the actual engine, i reccomend you just stick with not having the cool expanding o-ring too..... if oyure running it at 100 PSI, your pistons cant make more than 50 by moving up.... and if its at 100 PSI it should still be enough to make it work just fine.... if your counerweight or flywheel has that much momentum.

if i were you, id just try it. what do you have to loose?