What's a better combustion tank?

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.
Grandtheftyourwife
Private
Private
Posts: 10
Joined: Thu Sep 18, 2008 12:46 am
Location: Castleton,VT

Mon Sep 22, 2008 10:36 pm

Using schedule 40 pvc what would be a better combustion as well as more combustion a longer 1.5''tank of 27'' or a 20'' of 3''? Im shoting for distance but trying to get it right .Please help me modify this better for distance
User avatar
biggsauce
Specialist 3
Specialist 3
Posts: 338
Joined: Thu Jun 07, 2007 9:42 pm

Mon Sep 22, 2008 11:07 pm

I would DEFINITELY go with the 20" diameter pipe. It may be hard finding fittings for it though... Maybe go with 4" of it.







:roll:
Last edited by biggsauce on Mon Sep 22, 2008 11:13 pm, edited 1 time in total.
User avatar
Lentamentalisk
Sergeant 3
Sergeant 3
Posts: 1202
Joined: Tue Aug 07, 2007 5:27 pm
Location: Berkeley C.A.

Mon Sep 22, 2008 11:08 pm

Please. Use, Punctuation: It? Really! Helps; Us Read What. You, Are: Saying!

Use your Algebra. the area of a circle is (pi)r^2, so the area of a cylinder is h(pi)r^2. Calculate which is bigger. The larger diameter tends to be better because you have a larger burn rate.
Do not look back, and grieve over the past, for it is gone;
Do not be troubled about the future, for it has not yet come;
Live life in the present, and make it so beautiful that it will be worth remembering.
User avatar
MrCrowley
Moderator
Moderator
Posts: 10078
Joined: Fri Jun 23, 2006 10:42 pm
Location: Auckland, New Zealand
Been thanked: 3 times

Mon Sep 22, 2008 11:19 pm

biggsauce wrote:I would DEFINITELY go with the 20" pipe. It may be hard finding fitting for it though... Maybe go with 4" of it.


:roll:
If you are implying what I think you are, technically he implied using 3" diameter pipe when he said '20" of 3"', not 20" diameter pipe. :)

Lentamentalisk is right though, go with the larger diameter pipe. The closer the pipe resembles are sphere, the better the combustion.
A long barrel will make a big difference though, with a 20" long 3" chamber, a 4' barrel be optimal in the terms of performance, ergonomics and practicality.
User avatar
starman
Sergeant Major
Sergeant Major
United States of America
Posts: 3027
Joined: Wed Dec 12, 2007 12:45 am
Location: Simpsonville, SC

Donating Members

Mon Sep 22, 2008 11:28 pm

Please punctuate your sentences better. It's hard to tell what you are asking here.

This really depends on your barrel size. If you are shooting spuds, 1.5" is your barrel size of choice. You usually see a chamber made of 3" or 4" dia PVC for this purpose. A 16" long, 4" dia chamber and a 5', 1.5" barrel will make a pretty fair performer for distance. A longer barrel will do somewhat better but becomes impractical and will bend more. Also, spuds will have a natural distance limit based on irregular shapes and drag. 200 - 250 yards is about your distance limit, no matter what your propelling it with.
Post Reply