Flame Thrower

[mad max]

Iv'e been thinking about making a flame thrower for my bikes exhaust. Nothing fancy just a car's windshield sprayer motor and a small plastic tank. Has anyone ever tried this? What would be the best type of ignition source battery or coils?

thnx
mad max

[Jax]

You can do it with your exhaust and not have to build anything....set your bike to run a bit rich...attach a spark plug into the end of the exhaust...put a switch that will ignite a spark...fumes coming out will ignite and you'll have a flame thrower...there is a company that actually sells the kit...do a search and you'll find it..

[StevieB]

If you really want to do it...

Tap off from your gas tank a VERY small, fuel-resistant hose. I would think gravity feed would do okay, no pump should be necessary. Plumb some sort of timer or limiter into it, so that you don't get too much fuel flowing out. A little would go a long way. The spark plug idea from Jax will work, but I think you would need a way to increase the voltage- that's what coils do, altho you would not need 20,000 volts- that is required inside the combustion chamber, where pressure is much higher than atmosphere. A better setup would be a piezo ignition from an outdoor gas grill, available at Home Depot.

Wire the setup so that all you have to do is hit a button- the system releases a pre-determined amount of gas, and then ignites it.

Oh, and have an extra exhaust can in reserve- you will blow the first, maybe the second or third, apart at the seams, until you get the fuel metering amount right.

A crazy idea. But, hey, we are all crazy, at some time or another.

[DreKat]

hmmm flame thrower, that would stop tail gaters

[carpenter115]

hmmm flame thrower, that would stop tail gaters

My thoughts exactly
I have bungs I can weld to the exhaust, and I was going to use an older Chevy coil (the old canister style from the 70's), But the Piezo idea sounds feasable, not to mention just as low-cost. My plan for fuel was to just throw the choke (and possibly mark the spot where the lever gives the best results) and hit a "momentary on" switch.


All of this "For Offroad or Show Purposes Only"

[zique]

it's an interesting concept. I've never thought about it for a bike, but had it on an old truck once. My set-up was w/ the spark plug, but you have to be careful the flame stops before the exhaust pressure does or you can suck the flames back into your engine.

[zique]

DANG INTERNET! *Double post removed*

[The CyberPoet]

I'm going to be the nay-sayer here:

If you do this, you will want to use some form of metal spray apparatus to deliver the fuel into the exhaust, one that shuts completely again (think fuel injector). The last thing you want is a flame traveling back up the feed line to your fuel storage from the heat of the exhaust or from the sparked-off explosion.

Zique is right about issues with pressure waves and flame fronts working their way backwards through the headers to the exhaust valves (keeping them from opening on demand, exposing them to more heat than they should see, etc). I've seen single-sided exhausts get a false second side just to act as the "flame-thrower" (works in motion if the front end is open to the air; if you need it to work standing still, you need to pressurize the container with a fan or other fresh-air source, or alternatively, move to something other than gasoline, such as a flamable gas with oxygen in the mix).

Back when I was in high school (yeah, back in the bronze ages -- SpecialK was in the last stone-age class ), it was common to rig small containers of tranny fluid into car exhausts to be able to make a smoke-screen on demand... That's much simpler, because it doesn't have an explosive nature.

Cheers,
=-= The CyberPoet

[Frilock]

Sorry to revive an old topic, just wondering if there's been any kind of success?

[StevieB]

Cyber is spot-on here. I was in a playful mood when I posted my suggestions. Probably way TOO playful.

And there is the whole group of problems that can arise with the use of raw gasoline and spark outside the combustion chamber... can you say Katana Flambe?

[Frilock]

http://www.bahntech.com/products/FlameShift/default.asp

Don't know if it works for bikes (or works at all for that matter. But if you're still interested in the project, you might want to check here!

[StevieB]

Don't think it would work on a Kat. No TPS, no way to tap in so that it would be triggered.

Neat approach to the "problem," but I would wonder if it might not damage the ECM or some sensor or servo, or at the very least trigger the "check engine" light, and set a false trouble code that would cause good components to be thought bad, and thus replaced. You can't get a refund on electrical components at most parts houses. That can get expensive.

[The CyberPoet]

Don't think it would work on a Kat. No TPS...

98+ Kats have a throttle position sensor on the right end of the carb stack. On the other hand, your exhaust would look pretty stupid with a spark plug sticking out of it!

Cheers,
=-= The CyberPoet

[Wade-Kat600]

I used to have a 49 willies pickup with a tricked out motor in it - used to shoot flames 4 feet out the back of the truck when you took it over 6 grand - was quite spectactular at night - looked like you were behind an f14 or something....cops didnt like it much....one even checked the hood of his car when he pulled me over...oops