I need combustion chamber math help for 3 or 4" barrel.

Boom! The classic potato gun harnesses the combustion of flammable vapor.
Essohbe
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Alright, I am TERRIBLE with math and I need help figuring out how big a combustion chamber I'd need for a 6" PVC chamber with a 4" PVC barrel (or 3").

Will be metered propane most likely. I know there's formulas but I don't know how to add in all my variables.

Thanks anyone for any direction you can give me.
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mobile chernobyl
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If you haven't already - read this:
http://www.spudfiles.com/spud_wiki/inde ... rrel_ratio

And all you need to know is there.

You really should be able to do this little bit of math!
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CS
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jsefcik
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what ever your chamber is double that with your barrel,

if your chamber is 1.5 feet make your barrel 3 feet and so on
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mobile chernobyl
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Sorry Jsefcik - that does not work in all cases. In fact, that will rarely work. Sure it will produce a spud gun - but not an optimized one.
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pneumaticcannons
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I am TERRIBLE with math
Not exactly the best hobby to be terrible at math in.
Don't take that the wrong way, i'm not telling you to quit, just ask your math teacher for help or something... lol
How old are you?
ramicaza <- My Youtube Channel
Essohbe
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Very cool, thanks guys. I think I got it. That calculator link is AWESOME btw...

LOL, yeah I'm 32 BTW... I failed every math class in high schooll then flunked 6 of them in college until they let me take geometry instead which I tested out of. Go figure.
jsefcik
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mobile chernobyl wrote:Sorry Jsefcik - that does not work in all cases. In fact, that will rarely work. Sure it will produce a spud gun - but not an optimized one.

thats what i always went by, sorry about that
Essohbe
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Does putting a bend in the barrel coming out of the chamber impede the combustion at all or affect the ratio? I've seen both types of straight and bent chamber-to-barrel designs and it doesn't seem to matter.

Any comments?
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PaperNinja
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It slightly reduces flow, but I don't think the effect is very significant.
Essohbe
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Good to hear.

QWERTYUIOP{ASDFGHJKL
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