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1project2many · 10-20-2013, 10:31 PM

Use a late model HEI ignition module as a separate trigger for your coils. Trigger it off the engine coil. Run a wire from Coil- to HEI pickup coil +. Connect the pickup coil - to ground through a switch. This solves the problem of having too many coils on one set of points and burning up the points too quickly or reducing spark at the plugs and stalling the engine.

Fire at the tailpipe needs fuel and air to burn. Killing half of the cylinders puts fuel and air together ready to burn but blowing them down the exhaust fills the muffler and pipes with an explosive combination just waiting for a trigger. Anyone who's played the game of killing the ignition on a standard trans while rolling in gear then turning the key back on knows just what happens. Even welded mufflers get destroyed after a while. Better to introduce fuel near the rear of the exhaust and make a blowtorch style tip that mixes air and fuel after the tailpipe. I'd go with propane with a manual shutoff valve at the tank and a 12V valve from an RV heater much closer to the exhaust system.

FWIW I've built a system like this and it made big fire and a rumble that could be felt as well as heard.

10-20-2013, 10:31 PM	#10
1project2many Registered User Join Date: Mar 2012 Location: Lakes Region NH Posts: 3,158	Re: building flame throwers Use a late model HEI ignition module as a separate trigger for your coils. Trigger it off the engine coil. Run a wire from Coil- to HEI pickup coil +. Connect the pickup coil - to ground through a switch. This solves the problem of having too many coils on one set of points and burning up the points too quickly or reducing spark at the plugs and stalling the engine. Fire at the tailpipe needs fuel and air to burn. Killing half of the cylinders puts fuel and air together ready to burn but blowing them down the exhaust fills the muffler and pipes with an explosive combination just waiting for a trigger. Anyone who's played the game of killing the ignition on a standard trans while rolling in gear then turning the key back on knows just what happens. Even welded mufflers get destroyed after a while. Better to introduce fuel near the rear of the exhaust and make a blowtorch style tip that mixes air and fuel after the tailpipe. I'd go with propane with a manual shutoff valve at the tank and a 12V valve from an RV heater much closer to the exhaust system. FWIW I've built a system like this and it made big fire and a rumble that could be felt as well as heard.