www.pulse-jets.com

Although I began building an Electra (2) pulsejet over a year ago, I never got that far with it and for a while it was just propped up in my workshop doing nothing. I want to try and pick up from where I left off, and I have a few questions.

* What is required for the ignition setup? I already have a spark plug and a thread welded to the jet, but do I neee an ignition coil? I presume you need cables and a battery, and do you what about a switch?
* My tailpipe is 7/8", and my intake is 3/4". Would it still work?
* How important is it to have a flare on the intake?
* What do I need in terms of apparatus for the gas supply? Hoses, cylinders/canisters, regulators ect?

Anyone?

Hi Stormed,
Eric's " Running Pulsejets - Setting up and running pulsejets SAFELY"
should answer most of your questions.

Stormed wrote: * What is required for the ignition setup? I already have a spark plug and a thread welded to the jet, but do I neee an ignition coil? I presume you need cables and a battery, and do you what about a switch?
* My tailpipe is 7/8", and my intake is 3/4". Would it still work?
* How important is it to have a flare on the intake?
* What do I need in terms of apparatus for the gas supply? Hoses, cylinders/canisters, regulators ect?

Stormed -

Apologies for not responding to your email. I am just kind of ... slow.

I still think the best ignition setup is a Model T Ford spark coil and rechargeable 12-volt battery. Rig it with a pair of 6 ft long ignition wires w/ crocodile clips for the plug connection; use a toggle switch between the battery and coil. Google for it, search on eBay or find the coil at an antique auto swap meet or some such.

Those pipe sizes should work. You may have to shorten the tailpipe a little and use a metal sleeve over the tail end to tune it so it will run on its own. Some experimentation required.

A good intake flare is crucial. Just use heat and a regular ball peen hammer. It only seems difficult if you've never tried it.

A regular 20 lb propane tank will work for an engine this size, even with an OPD-equipped valve. No regulator needed - a poorly sized (i.e. inexpensive) regulator is far worse than working without one. You should be able to find a propane hose with a simple fitting that connects to the cylinder valve (try any place that sells lots of propane outdoor grilles. etc.). You'll just have to adapt the end that connects to the engine fuel pipe.

L Cottrill

Can I run the engine on butane?

Stormed wrote:Can I run the engine on butane?

You might get away with this, if you live in a place that is normally nice and warm. Butane has MUCH less vapor pressure than propane at a given temperature. I have always wanted to see somebody get a valveless pulsejet running on butane, but it is going to be difficult when there's such low pressure to work with.

L Cottrill