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Tom Laferriere

Now for something completely different. Purposely making a backfire

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Hi all,

Another unusual request.

TASK: I want to make a vintage car backfire on command.

I don't want to do something within the engine itself, but more in the exhaust pipe. I am thinking of a spark plug in the pipe towards the back of the car which is triggered by a switch, but will need a fuel source "injected" right before the plug. Not only do I want a back fire, but I want it loud.

Thoughts?

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Thats called a flame thrower.You can get them on ebay.But when I was in school ,we would turn the engine off and pump the gas peddel with the car in gear say 30-35 mhp,Turn the key to on,and BANG!Hard on your muffler.But fun.

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I understand what flame throwers are and I dont want this. I am looking for a backfire on command when the motor is running.

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Very simple. Turn the ignition off then back on again. Don't leave it off too long, you will blow the muffler off the car.

Or, install a cutout and let 'er bark.

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The car will have no muffler...it will be straight pipe. I really dont want the engine to do the backfiring, something after the motor.

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Tom-- Buy some firecrackers, light them and drop them on the road as needed. ---Bob

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Tom,

You might try injecting an air/propane mixture ahead of the spark plug in the tail pipe......

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Tom -- I apoligize, I expected you to take as it as a joke or a bit of levity.Sorry --Bob

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Back when I was flying some airports had bird scaring cannons scattered around the field. They were automatic, fired every few minutes, and were fueled by propane. They were VERY loud. A little research would probably yield the basic design and I'd be surprised if you couldn't adapt it to what you need. Most likely a bernz-a-matic tank would be enough fuel supply for your needs..............Bob

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Turning the ign off with the engine in gear 20-30 mph will pump gas/air mix into the exhaust pipe, when you turn the ign back on the hot exhaust lights it off with a

BANG, if your just running a straight pipe you might need a small can to trap the mix. It only needs a few seconds. I used to do that with my 1930 Buick 47, it was really loud in the Boston's Sumner tunnel , but tough on the muffler.

JB

Buick 22-6-55 Sport Touring

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Tom, check locally and see if you can find someone with a car rigged to do that in parades. Sometimes people build what they call "clown cars" and they know how to rig them to do what you are wanting to do. They know how to rig squirters to get the crowd wet too. :eek::D

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Talk to the people at Old Rhinebeck Aerodrome. They stage aerial dogfights with WWI planes. They have some sort of propane(?)-burning rig that makes it sound as though their machine guns are firing.

Gil Fitzhugh, Morristown, NJ

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The stuff at Old Rhinebeck is set up by a licenced pyrotectic expert. Years ago, before 9/11 there was a lot more stuff that you could get away with. But nowadays, thing are very stringent, especially at an Air Show. A lot of the car chase sceens with the, escaped convict, and the Black Baron is done with shot guns and blanks. I know, because I have driven one of the chase cars from time to time. They no longer allow the phony machine guns on the planes to work because of the danger of an explosion. I think they were propane, or accetalene. All the noises are now made on the ground. Not sure how they worked, but I may be able to find out but not until things re-open next spring. Dandy Dave!

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Tom -- I know I have to be serious for you, so I'm elaborating a little on Bhigdog comments. Operators of vineyards and fruit growers have been using these noise producers for some time. Probably on a smaller scale than the ones used around airports, but they may assist your needs.--Bob

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Sometimes people build what they call "clown cars"

Hey! Susan, I heard that!!:D:D:D:p

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Tom,

I saw a piece on the GEARZ TV Show how hollywood prop makers make machine guns look and sound real by injecting propane and igniting it electrically. He mounted twin machine guns on the monster truck in the studio and demonstrated how they work.... I looked up the show online, but couldn't locate that episode.

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Hey! Susan, I heard that!!:D:D:D:p

Skyking, do you have one of those? A friend of ours built one years ago. He has since passed away but his widow still owns it. Not sure if it backfires or not but it does have barbed wire for the spark plug wires and very little paint other than the funny stuff written on it. I think it has the squirter on it. Someone likes the car so well that they carved a big sleeping hound dog that they put on the running board on cool days or up under the car on hot days when they park it. It even has a leather collar with tags on it. Very cute.

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