In theory, remote controlled cars are great, but in practice they're just never quite exciting enough for me. That is, until I decided to attach a jet engine to one. Yes, you read that right – a jet engine.
Pulse jets are a simple type of jet engine with no, or very few, moving parts, depending on the design. The jet I used had only one – a reed valve made of spring steel shaped like the petals of a flower. Rather than relying on complex internal machinery, pulse jets instead work with the resonance of the exhaust gasses in the tailpipe. This simplicity means that you can get ones small, light, and cheap enough to put on a model plane – or an RC car.
To attach a jet to the chassis of my Radio Shack RC car, I fabricated simple brackets out of steel. They also strengthened the chassis and added some weight, which made the jet-car slightly more controllable, although only very slightly. Spring loaded hose clamps held the jet to those brackets. For the nitromethane and methanol mix that fuels the jet, I installed a “clunk tank,” which is typically used in RC planes, inside the body of the truck.
As I'd suspected it would, the 4 pounds of thrust produced so greatly overpowered the little car that attempts to drive it were comical – and I throughly enjoyed every second of it. For every kid who's ever strapped model rocket motors to a toy car; I'm living the dream. If I were to do this again with a bigger car that could actually keep the shiny side up under jet power, I think I might be on to something big. And loud.
RC Pickup Truck – Radio Shack - p/n 60-594 – www.radioshack.com
Pulse Jet – Jet Bill Products & JohnMar Gear and Machine - www.jetbillproducts.com
6oz Clunk Tank – Hobby People - item # 568469 – www.hobbypeople.net
Fuel Tubing – Hobby People - item # 567776 – www.hobbypeople.net
HD Motorsports Hero Camera – GoPro – www.gopro.com
Various steel, hose clamps, and fasteners – McMaster – www.mcmaster.com