ok so i was thinking about building a combustion launcher from some 3/4 pvc and a 2 liter soda bottle. I just want it to shoot paintballs at a fairly low velocity (below 300 fps). I have all my plans and shit worked out and i was wondering what you guys would think about me trying direct injection on this bad boy?
I would do the crack lighter trick to amp up the fuel injection so it wouldn't take forever
thinking about direct injection
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Novacastrian
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What exactly do you mean by "direct injection"?
America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
WTF does this meanI have all my plans and crap worked out and i was wondering what you guys would think about me trying direct injection on this bad boy?
I would do the crack lighter trick to amp up the fuel injection so it wouldn't take forever
Coodude26 wrote:
People who laugh really hard at stuff that pisses you off/you getting hurt, who then say "I'm sorry, I can't stop" but you know they easily could.
Mr.C: That's not as easy as you think. It's like me kicking you in the balls and telling you to stop crying.
People who laugh really hard at stuff that pisses you off/you getting hurt, who then say "I'm sorry, I can't stop" but you know they easily could.
Mr.C: That's not as easy as you think. It's like me kicking you in the balls and telling you to stop crying.
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Novacastrian
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I take it a "Crack lighter" is one of those jet cigarette lighters?
Edit: Drugs are bad mmmmk... Don't take drugs mmmmmmmkkk.
Edit: Drugs are bad mmmmk... Don't take drugs mmmmmmmkkk.
Last edited by Novacastrian on Tue Jan 08, 2008 9:28 pm, edited 1 time in total.
America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
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F.E.A.R._Sniper
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like a barb is screwed into the chamber and the hose is run off to the fuel source (lighter in this case) and when you push the button it pumps the fuel into the chamber instead of having to spray shit into the chamber by unscrewing everything
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Novacastrian
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How does one propose to implement the exchange of dead air for new air?
America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
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brogdenlaxmiddie
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you need to greatly elaborate on your question and description 
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F.E.A.R._Sniper
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a ball valve between the barrel and chamber that opens to the air so you can vent the chamber. dude I'm not retarded i know that if you don't vent then any unburned gas will make the fuel mix too rich and it won't ignite
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Novacastrian
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I did not call you retardedF.E.A.R._Sniper wrote:a ball valve between the barrel and chamber that opens to the air so you can vent the chamber. dude I'm not retarded i know that if you don't vent then any unburned gas will make the fuel mix too rich and it won't ignite
That aside are you sure that one ball valve will suffice? Maybe two would be better as you could provide an air flow to really make sure that you have fresh air in the chamber. That said if the barrel extended into the chamber i suppose one valve would be enough.America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
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F.E.A.R._Sniper
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yeah the barrel will go back into the chamber a little bit.
it is actually built like this.
take the bottle and lay it on its side. then stick a short piece of 3/4 down the neck of the bottle and make JSR happy and epoxy it into the neck. on the other end put a tee on there. on the direct opposite side of the chamber place a small section of 3/4 with the ball valve on the other end. from the top of the tee you have enough 3/4 to clear the chamber and then you mount a 90 on there to make the barrel run paralel (sp?) with the chamber. then fire it off some!!!
it is actually built like this.
take the bottle and lay it on its side. then stick a short piece of 3/4 down the neck of the bottle and make JSR happy and epoxy it into the neck. on the other end put a tee on there. on the direct opposite side of the chamber place a small section of 3/4 with the ball valve on the other end. from the top of the tee you have enough 3/4 to clear the chamber and then you mount a 90 on there to make the barrel run paralel (sp?) with the chamber. then fire it off some!!!
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Novacastrian
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People think that i'm weird when i "suck" on my cannons, i think you may fall into that catagory! 
What? it's the best way to ensure a good fuel load!
What? it's the best way to ensure a good fuel load!America, the greatest gangster of all time. With 200 million odd foot soldiers at it's whim and call.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
When you fill your car with refined oil remember that it has been paid for with blood and guts, some from your own countrymen, most not.
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F.E.A.R._Sniper
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into the "I suck on my cannons" category?
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jimmy101
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Yes, direct injection from a butane lighter will work fine. Just need a piece of hose with a suitable ID to fit onto the nozzle of the lighter. I've had good luck using the insulation stripped off a piece of 20G wire.
(from here)
You can just drill a small hole in the chamber and glue the end of the hose into it. Doesn't have to be all that strong since the force on the junction is going to be pretty small.
You don't need a valve between the chamber and barrel. You can just inject fuel after the ammo is loaded.
Venting will be a PITA. If you have a compressor, or a can of compressed air, you can use that to flush out the chamber between shots by pumping air in through the muzzle. You could just stomp on the bottle a few times to exchange the combustion products for fresh air but that will weaken the bottle pretty quickly.
Might want to put a few packing peanuts in the chamber so you can shake the chamber to get the fuel and air to mix.
This method of fueling is very sensitive to the ambient temperature. The pressure in a butane lighter, and hence the flow rate, is very sensitive to temperature. At 80F the lighter is pressurized to about 2.5 ATM, at 40F it is only about 1.2 ATM.
(from here)You can just drill a small hole in the chamber and glue the end of the hose into it. Doesn't have to be all that strong since the force on the junction is going to be pretty small.
You don't need a valve between the chamber and barrel. You can just inject fuel after the ammo is loaded.
Venting will be a PITA. If you have a compressor, or a can of compressed air, you can use that to flush out the chamber between shots by pumping air in through the muzzle. You could just stomp on the bottle a few times to exchange the combustion products for fresh air but that will weaken the bottle pretty quickly.
Might want to put a few packing peanuts in the chamber so you can shake the chamber to get the fuel and air to mix.
This method of fueling is very sensitive to the ambient temperature. The pressure in a butane lighter, and hence the flow rate, is very sensitive to temperature. At 80F the lighter is pressurized to about 2.5 ATM, at 40F it is only about 1.2 ATM.
