Help for propane injection

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.
User avatar
joannaardway
Corporal 5
Corporal 5
Posts: 949
Joined: Mon Oct 09, 2006 4:57 pm
Location: SW Hertfordshire, England, UK.

Wed Mar 28, 2007 2:46 pm

Well, my little bit o' maths tells me that your ideal ratio for 30% propane/70% butane is 3.5% almost exactly.

My work here is done.
*dissappears into a wall*
Novacastrian: How about use whatever the heck you can get your hands on?
frankrede: Well then I guess it won't matter when you decide to drink bleach because your out of kool-aid.
...I'm sorry, but that made my year.
User avatar
CannonBall
Specialist
Specialist
Posts: 102
Joined: Tue Mar 20, 2007 5:16 pm

Wed Mar 28, 2007 2:48 pm

But how about the mano meter it is not precise...
it goes per 0.1 bar.
can i use this mano meter?

Ow and when i shoot with common hairspray i get a range of 450feet.
Calculated with google earth.

does the propane/butane mix increase my range much?

Cheers
User avatar
joannaardway
Corporal 5
Corporal 5
Posts: 949
Joined: Mon Oct 09, 2006 4:57 pm
Location: SW Hertfordshire, England, UK.

Wed Mar 28, 2007 2:59 pm

Sounds to be quite a bit of range, not impossible though.

A good metered cannon with the normal assorments can get 200 yards to 300 yards of range depending on how well it's behaving.
Novacastrian: How about use whatever the heck you can get your hands on?
frankrede: Well then I guess it won't matter when you decide to drink bleach because your out of kool-aid.
...I'm sorry, but that made my year.
User avatar
willarddaniels
Specialist 2
Specialist 2
Posts: 286
Joined: Wed Jan 31, 2007 2:34 pm
Location: Idaho

Wed Mar 28, 2007 4:06 pm

As always... I'm no expert, just a thinker.
joannaardway wrote:Well, my little bit o' maths tells me that your ideal ratio for 30% propane/70% butane is 3.5% almost exactly.
You are very correct. I just didn't want to look it all up. Now that you got me thinking about it, -thanks- I have. Researching the stoichiometric ratios on WIKI[/quote] and finding that Butane is C4H10, the ideal fuel to air ratio of a 70% Butane, 30% Propane mix is very close to 3.5%

That being said, someone can go here to read about how to make a fuel meter.
If you're 20 and not a liberal, you don't have a heart. If you're 30 and not a Conservative, you don't have a brain.
User avatar
CannonBall
Specialist
Specialist
Posts: 102
Joined: Tue Mar 20, 2007 5:16 pm

Thu Mar 29, 2007 3:25 pm

well i have my meter now.
it works fine :lol:
but my mano meter only goes to 2.5bar will that be enough to measure out the mix?

Patrick :P
User avatar
Brian the brain
Moderator
Moderator
Netherlands
Posts: 3497
Joined: Mon Dec 05, 2005 2:06 am
Location: Holland
Been thanked: 6 times

Thu Mar 29, 2007 3:50 pm

I thought you guys knew I'm a pneumatic kinda guy!!!
But that has to do with legal reasons...Hybrid offers more speed ( wich is NOT the same as power!!) than pneumatic, so I AM interested, but I want to keep it legal.I started a hybrid-build some time ago, but I gave up on it.
Never figured out the fuel ratio.I figured I might as well use powder, since it is illegal anyway.
And since powder has the tendency to send scrapnel through my last name...I never tried that either.

And to tease all of you I will now say something extremely important in DUTCH: :D :D

Over een tijdje ben ik gewoon weer aangesloten op het wereldwijde web!!
Via een inbelverbinding, dus langzaam, maar ik blijf wel hier!!!

Let's see how long it takes for the message to spread.

Now some legal advise in Dutch for my fellow countrymen ( not important to you spoiled Americans :D)

Alle "wapens"die een projectiel verschieten door middel van een chemische reactie ( verbranding-ontploffing) vallen onder de vuurwapenwet en zijn dus verboden zonder vergunning.
Met luchtdruk kun je niet alleen de wet omzeilen, je kunt er ook veiliger, schoner en accurater mee werken.Bovendien levert het krachtigere kannonnen op!!!
Ik heb nu weinig tijd, maar ik ben bereid je te helpen om je kennis op te schroeven op dat gebied mocht het nodig zijn..


All we need now is a meet in Holland..
Gun Freak wrote:
Oh my friggin god stop being so awesome, that thing is pure kick ass. Most innovative and creative pneumatic that the files have ever come by!

Can't ask for a better compliment!!
User avatar
CannonBall
Specialist
Specialist
Posts: 102
Joined: Tue Mar 20, 2007 5:16 pm

Fri Mar 30, 2007 9:11 pm

JUst made my injection system..
It works Great 8)
AT 2 bar i had no misfires .... 20 out of 20
perfect mix is at 2 bar.

Thanks guys for your good help


cheers Patrick
Last edited by CannonBall on Sat Mar 31, 2007 6:10 am, edited 1 time in total.
User avatar
willarddaniels
Specialist 2
Specialist 2
Posts: 286
Joined: Wed Jan 31, 2007 2:34 pm
Location: Idaho

Fri Mar 30, 2007 11:05 pm

congrats B the B, it'll be good to have you here nog steeds.
Ouch. That is rough with the weapon/gun laws in Nederland. You may as well build a kicking hybrid and register it.

Congrats on the injection system canonball, be careful.
If you're 20 and not a liberal, you don't have a heart. If you're 30 and not a Conservative, you don't have a brain.
User avatar
CannonBall
Specialist
Specialist
Posts: 102
Joined: Tue Mar 20, 2007 5:16 pm

Sat Mar 31, 2007 6:18 am

Willard the fuel tool was really helpfull.
I had calculated that i needed 2 bar at my meter. and it was correct.
I have tested different ratios too but 2 bar was the best.
bleu flame each time with good presure behind it.
With open chamber you could hear a WHOOOMP.
With closed camber a real PAKKKK.... a real sharp sound :lol:
With a knocking recoil 8)

Today i will fire some shots and calculate the distance with google earth, i will post the distance tonight.

Patrick
User avatar
willarddaniels
Specialist 2
Specialist 2
Posts: 286
Joined: Wed Jan 31, 2007 2:34 pm
Location: Idaho

Sat Mar 31, 2007 10:06 pm

That is sweet, Patrick ... I knew a Patrick in R'dam ...
It is always awesome to see/hear about when folks get their first metered propane to work well. Yup, 2 bar should be the best, as long as your propane chamber is 4% the volume of your combustion chamber.
Again, great job!
If you're 20 and not a liberal, you don't have a heart. If you're 30 and not a Conservative, you don't have a brain.
User avatar
CannonBall
Specialist
Specialist
Posts: 102
Joined: Tue Mar 20, 2007 5:16 pm

Mon Apr 02, 2007 5:01 am

Well im very happy to but still have to instal a chamber fan.
it works better with a chamber fan.
But that is almost done with no problems.

I live in R'dam :lol:

Patrick
User avatar
willarddaniels
Specialist 2
Specialist 2
Posts: 286
Joined: Wed Jan 31, 2007 2:34 pm
Location: Idaho

Mon Apr 02, 2007 12:00 pm

This guy was in Hoogvliet...
Where the heck do you shoot your cannon?!
If you're 20 and not a liberal, you don't have a heart. If you're 30 and not a Conservative, you don't have a brain.
User avatar
CannonBall
Specialist
Specialist
Posts: 102
Joined: Tue Mar 20, 2007 5:16 pm

Mon Apr 02, 2007 2:11 pm

Hoogvliet, i live 2 km from hoogvliet... Poortugaal.
I shoot my cannon at the MAAS u must know it its a very big river.
Did u went to (het bruine cafe) Its a Pub.

Patrick
User avatar
willarddaniels
Specialist 2
Specialist 2
Posts: 286
Joined: Wed Jan 31, 2007 2:34 pm
Location: Idaho

Mon Apr 02, 2007 10:08 pm

I think I ventured into Poortugaal twice... because I was either bored or I got off at the wrong metro stop by accident. :lol: I mainly just zipped on by. That would explain how you can get by with firing the thing in the city... just head to the edge of town and blast away. I had thoughts of you living near Eneco Stadion.
Nah, I never made it there... I'm not much of a drinker and was a work-aholic.

Marc
If you're 20 and not a liberal, you don't have a heart. If you're 30 and not a Conservative, you don't have a brain.
the c3h8er
Private
Private
Posts: 8
Joined: Fri Apr 06, 2007 5:45 pm

Sat Apr 07, 2007 9:32 pm

well we all know that butane is a bastard gas according to hank Rutherford hill. Jk :lol:
Post Reply