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Posted: Sun Mar 11, 2007 5:09 pm
by A-98
arg, im terrible at ratios. could you help me with the C:B ratio pete?
i have a chamber that is 301 cubic inches, and a barrel that is 63 cubic inches. i did what you did and got .79:1, but i have no idea if that is correct. could you tell me how to do it?
Posted: Sun Mar 11, 2007 7:22 pm
by LosBuenos
do you need fans if you give the cannon time to cool off after each shot? with propane injection there should be enough air/fuel mixing happening i think.
Posted: Sun Mar 11, 2007 8:31 pm
by fom
LosBuenos wrote:do you need fans if you give the cannon time to cool off after each shot? with propane injection there should be enough air/fuel mixing happening i think.
A fan is for venting the chamber after shots (getting a new oxygen supply) and mixing the fuel/air so there is a even concentration.
Posted: Sun Mar 11, 2007 8:34 pm
by willarddaniels
Using a fan to mix your fuel before and during combustion gives a HUGE incerase in overall power. I can't remember the numbers, but somerwhere in the range of +31%
The fuel mixing is the most important task a fan does. The second task: cooling/fresh air supply only reduces time between shots.
Posted: Sun Mar 11, 2007 10:34 pm
by A-98
i hope you guys arent replying to me, cause i forgot to mention that mine was going to be a pneumatic
....now that i think about it, im going to make a new thread
Posted: Tue Mar 13, 2007 5:29 pm
by LosBuenos
so the fan needs to be blowing into the chamber or out? (wow 31%!)
Posted: Tue Mar 13, 2007 5:41 pm
by willarddaniels
The fan should be completely enclosed in the combustion chamber. You can access it by removing a plug on the end of the chamber. I usually mount the fan in the back 2" of the chamber and direct the flow toward the barrel.
I am not sure where or in which direction others mount their's...
Posted: Tue Mar 13, 2007 7:35 pm
by PVC Arsenal 17
LosBuenos, I suck.
Posted: Wed Mar 14, 2007 4:06 pm
by LosBuenos
i'm sorry to hear that. why do you suck?
Posted: Wed Mar 14, 2007 4:26 pm
by PVC Arsenal 17
I'm mean. According to your avatar that makes me suck.
Posted: Wed Mar 14, 2007 5:54 pm
by risto
i try not to suck, but when people are stupid...i can't help myself.
and is there a simple way to calculate what your barrel length would need to be inorder to make a good C:B ratio? i know how to get the volume of my chamber, but how do i figure out how long to make the barrel?
sorry, i suck at math...=[
Posted: Wed Mar 14, 2007 6:16 pm
by LosBuenos
i try not to suck, but when people are stupid...i can't help myself.
all of us get angry sometimes. its not your fault. i'm not good at math either. i cant help you.
Posted: Wed Mar 14, 2007 6:40 pm
by pyromanic13
wow... it smells like pussy in here, lets stop talking about our feelings.
seeing how we're off topic now, has anybody discovered the site
http://www.tuckermax.com ?
Posted: Wed Mar 14, 2007 9:25 pm
by risto
yeah, i've been a message board member for a few months, you can find me on there (risto).
I love that place.
Posted: Wed Mar 14, 2007 10:00 pm
by noname
For an easy method of adding barrel length, calculate how much volume 1 inch of the barrel has, then keep adding that number until you have a good ratio.