Chamber To Barrel Ratio

[JDSpud]

When your building a regular combustion spud gun, what raitio should you use between the area of the chamber and the barrel.

~JDSpud

[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.

[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.

[jjjd]

yeah search it up next time please

[dgr-c]

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

[Bluetooth]

I agree that he should have searched too but they weren't being too mean. 1.5:1 (even for metered propane Pete ) 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).

[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".