Help for propane injection

[CannonBall]

Hey, I was just reading about propane injections.
I am planning to make my own but....
How do i measure out the propane to the chamber ratio (air and fuel).
and the propane injector has to be easy to make.
If u have good ideas or plans plzz post.

Thanks Guys



Patrick

[MrCrowley]

Ive got four good ideas...

1)talk to Pete Zaria
2)Talk to sgort87
3)Talk to Spudblaster15
4)Talk to boilingleadbath

[CannonBall]

How can i calculate how much propane i have to inject..
Some thing like 4 psi or so into the chamber is a good ratio.
but my only concern is wouldn't de spud leave the barrel when i inject?

cheerzz Patrick

[noname]

www.advancedspuds.com
www.burntlatke.com
Both have FuelTool calculators.

[itwentboom]

4 psi are you kidding?

[hi]

I think he ment 4%. Yes thats about right. PSI is pounds per square inch, just in case you didnt know. Fuel meters are easy to make, you just need a 1/4 tee, 1/4 ball valve, pressure gauge, 0-30 or 0-60 work best, some hose and a few nipples and a torch head. Fueling is best determined by simple trial and error. The calculators dont take things like temperature into consideration. It just takes a few tries to get right.

[SpudBlaster15]

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[CannonBall]

Im gone use propane as fuel.
We dont have dont have PSI meter. we have BAR..
And I have a chamber that is bigger then 2 liter
I think i just have to test Propane to air ratio's
How precise has the meter to be?
Whats a pressure regulater?
ow and sorry for my bad english im dutch
Maybe u have have some good picture's for me for inspiration

Cheers

[Freefall]

The meter doesn't have to be very precise. Propane will ignite from about 2% (half of the perfect mix) to 9% (more than twice the perfect mix). But the closer you get, the more powerful your launcher will be.

There are more meter configurations available. Pretty much any setup that allows you to trap the propane between two valves with a gauge somewhere in between will work.

The simplest that I've seen used a section of air hose as the meter volume. On one end was just a standard propane torch head with the nozzle cut off. On the other end was a gauge and an air chuck. The user would open the bottle valve until the right pressure was indicated, then he'd close the bottle valve and press the chuck to a schrader valve on the chamber.
No regulator, no ball valves, no extra bits of pipe, no assembly of fittings.

Let us know what your chamber volume is, and we can tell you how much meter volume you need at various pressures. Tell us how you want to build it, and well tell you exactly what you need.

Have fun, don't get blown up.

[CannonBall]

I have countered a problem.
We dont have propane torches here only butane.
but i found a torch that works on 30% propane 70 % butane.
will this setup work to?
Another problem we only have mano meters till 5 bar witch counts at 0.1 BAR at a time is that precise enough?

cheers

[willarddaniels]

CannonBall, vind BriantheBrain en stuur een pm naar hem toe. Hij is ook een nederlander and kan je met jouw propane-probleem helpen. Sorry dat m'n nederlands niet het best is. 'tis een tijdje geleeden dat ik er woonde.

[CannonBall]

Ja bedankt ik zal hem even een PM sturen.

groetjes

[joannaardway]

sorry for my bad english im dutch

I assure you, your English is massively better than my Dutch.

A 30% Propane, 70% butane fuel can be used. It will need a different ratio, and will provide the tiniest amount less power, but it can work in exactly the same way.

[lukemc]

gaaa their talking netherlandish!! im an ignorant american and im just learning spanish. if theres anything important please translate im thinking about adding propane injection also

[willarddaniels]

Before designs are handed out again, I suggest folks look at the combustion cannon showcase and you will get a very good idea of the materials needed and the metering systems used.

lukemc, there was nothing important; I should have said what I did in a pm, I suppose. I just referred him to BriantheBrain since they both live in the same country, Brian can show him where to get the fuel he desires and do so in his native tongue.

Butane combusts from 1.9% to 8.5% whereas propane from 2.2% to 9.5%
Butane's flame speed is 10% slower than propane's
Butane's flame temp (in air) is less than 10% lower than propane's.

As Joanna indicated:
Butane is not as powerful, by a small margin which can be made up with chamber fans, multiple sparks, etc.
The ratios of fuel/air will only be slightly different but if you stuck with the 4% method, you should be fine. I imagine 3.8% would be optimal, but we are talking about a very small difference. At the worst, you will have a little less power, resulting in more soot/residual.