Fuel Injection - Help!

Boom! The classic potato gun harnesses the combustion of flammable vapor. Show us your combustion spud gun and discuss fuels, ratios, safety, ignition systems, tools, and more.
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tsb
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Wed Oct 10, 2007 6:44 am

Hello,

I am using just a basic combustion cannon i made from sch 40 PVC Pipe.
Its C:B ratio is 1:1 and i need to insert 40cc's of gas to make it 4% fuel and 96% air, and a person i was recently talking to said to get a syringe and use it that way.

What i dont understand is, i know that propane is a fluid, but it only takes that form when it is compressed, when you release it it turns into a gas.

How do i insert exactly 40cc propane, butane, LPG gas or whatever i'm using as a propellent?
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psycix
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Wed Oct 10, 2007 7:43 am

Propane is only a fluid when compressed or at very very low temperatures.
Out of the tank its a gas and so, you measure out 40cc of propane gas.
Inject that and there you go.
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benstern
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Wed Oct 10, 2007 11:14 am

Actually fluid by definition is gas or liquid or sometimes plasma.
silverdooty
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Wed Oct 10, 2007 11:31 am

I don't really have an answer, but if you were to search 'propane AND syringe' you should find about 49 results. some answers are vague while others are actually pretty good.
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tsb
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Wed Oct 10, 2007 5:09 pm

psy, yes your right, but i dont think i explained my self in full.

I need to know; how do you get 40cc in a syringe?
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jimmy101
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Thu Oct 11, 2007 12:51 pm

You can measure propane like this.
Or, using a disposable butane lighter as the fuel source, like this

The links are frequently down. Try again after a few minutes.
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