Small valveless

[multispool]

Bruno, I think anything smaller than this would be easier to machine all of it from solid. Welding gets impossibe especially in that sharp Vee between intake and chamber. I half formed the chamber, a kind of tapered U shape, welded the intake from the inside then finished the chamber (with difficulty), The plug mount was welded from the front opening before welding the front plate on. On hindsight I think it would be much easier to machine from solid, thread and screw together.
No, I'll leave someone else to machine a car from billet ! Might try a Ramjet next...

[Johansson]

When do you intend to run it?

//Anders

[multispool]

It will be a few days away. Have to make a spark generator first

[Eric]

Very nice job! It should work great. Robert K. build one at half scale using the same principle and it runs great.

Cant wait to see it running.

What kind of spark source are you making? Its probably easiest to make one from a weed wacker magneto and a drill, there are numerous benifits from doing that over the various electronic ignition systems, mostly it is dirt cheap.

Eric

[multispool]

A full size FWE just completed, Here it is next to its little brother...

[larry cottrill]

A beautiful pair, multi - nice looking work!

L Cottrill

[Jmitchell]

Wait a second! What happend to my thread about my miniature FWE? I posted it on Monday, and now it's gone?

[multispool]

BTW folks, Anyone having trouble forming a nice flare like on the intake shown above, I cut off a 4mm slice from some bar stock and welded it to the tube end with a generous fillet weld and then machined the flare!
Jmitchell, I missed your post, what scale is yors? Perhaps we can compare notes, Mine still not self sutaining!

[Eric]

You need to get them running side by side. Are you trying propane for the small one? It should run on propane no problem, just a matter of getting the right fuel injection speed and position.

For really small engines I make almost like a mini bunsen burner, that has a venturi hole a ways back in the fuel line, and a small fuel hole right before it, that way it takes in lots of air and mixes pretty good before it gets into the engine, but you dont want it to mix too much or you will have a torch at the intake.

You shouldnt have to resort to anything too fancy for something that size though.

Good luck

Eric

[Nick]

Wait a second! What happend to my thread about my miniature FWE? I posted it on Monday, and now it's gone?

Yes Steve posted a quiute brilliant little PJ running at about 800Hz and thats gone too?

Nick

[Jmitchell]

Mine was a half scale svelt lady. It would not self sustain when I was working with it earlier, however, I didn't try very many different fueling/air arrangments. My spark plug seems to have crapped out, and it's welded in :shock: .

[multispool]

You might be able to cut the plug off, leaving the body in place. Drill it out and tap a metric fine 10X1 thread. Thats providing of course that the central hole allows that!

Meanwhile, I'll play around with jet sizes and positions, but have three other projects on the go so can't give it 100% attention right now!

[Eric]

Sometimes heating the base of the spark plug with a propane hand torch can help things, depending on if it has any kind of grime built up on it, but you could always drill another hole and have another spark plug.

Eric