Page 1 of 1

Chamber To Barrel Ratio

Unread postPosted: Thu Jan 18, 2007 9:09 am
Author: JDSpud
When your building a regular combustion spud gun, what raitio should you use between the area of the chamber and the barrel.

~JDSpud

Unread postPosted: Thu Jan 18, 2007 9:25 am
Author: garrettee
I'm really not tring to be a d*ck, but search old posts(search) and check the Spudwiki section because it's very useful.

Unread postPosted: Thu Jan 18, 2007 6:14 pm
Author: Pete Zaria
It depends on the fuel.

As Garrattee said, you should search the forums and read the wiki. There's lots of info on this.

It's rumored (or should I say, agreed upon) that between 1:1 and 1.5:1 is best for hairspray and aerosol combustions, while .8:1 - 1:1 is best for metered propane. Keep in mind, if your chamber is too big you don't loose power - you just make more noise. For this reason I always tend to go a little chamber-heavy...

Peace,
Pete Zaria.

Unread postPosted: Fri Jan 19, 2007 1:23 pm
Author: jjjd
yeah search it up next time please

Re: Chamber To Barrel Ratio

Unread postPosted: Fri Jan 19, 2007 7:48 pm
Author: dgr-c
JDSpud wrote:When your building a regular combustion spud gun, what raitio should you use between the area of the chamber and the barrel.

~JDSpud


Lighten up guys. He didn't ask how many people would like to tell me to go f*ck myself.

Here's some research
http://www.burntlatke.com/launch.html

Try this online calculator
http://www.burntlatke.com/ratcalc.html

Unread postPosted: Fri Jan 19, 2007 7:57 pm
Author: Bluetooth
I agree that he should have searched too but they weren't being too mean. 1.5:1 (even for metered propane Pete :wink:) is a powerful ratio .8:1 is very efficient. The "best" fuel mix is 4.3 (don't ask why its such an odd number, it's
from Burnt Latke and he does bunches of tests to prove his data).

Unread postPosted: Sat Jan 20, 2007 2:56 pm
Author: boilingleadbath
JDSpud, you probably meant volume, in which case all of the above responses are correct.

However, if you acctualy meant <b>area</b>, it's another beast - and the response is "as big of a chamber diameter as is practical".