Brian does Ridders flame eater

[PJPickard]

Having just built it I can give you some pointers. Like don't make the flywheels as per print. Too many connections, just make the hub part of the flywheel. I will have to go and recut mine to get them to run true. PM me for any questions!

[NickG]

Paul, Poppin is a much different design I’ve made two of those and they ran on first flick too like yours. As you say, the only issue was getting everything tight enough not to move as it it flies around!

With my Jan ridders engine I experienced the same issues as Brian and I had cast iron cylinders. It runs, but not very fast and is very sensitive to flame position. I’ve never known a build of it where this wasn’t the case and most probably don’t run at all. Somebody came to me once at an exhibition with a beautifully made engine ( far more skill than me) and couldn’t understand how i got mine to run! The truth was I think that my poorer machining had meant that the fits weren’t as good and everything ran more freely!

I agree with Doc, the Ridders internal valve will always have performance issues due to its design.

Poppin is a great design and a lovely exercise to build, you’ll enjoy it.



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[Jasonb]

I've been thinking--which is probably a dangerous thing. I made my cylinder from 316 stainless to prevent any rust buildup inside the cylinder. (alcohol releases water when it burns). These flame licker engines depend on the heat differential between the flame they suck in and the cooler temperature of the cylinder to cool off the flame and create a vacuum. Someone pointed out that the thermal conductivity of stainless is only about 1/3 of the thermal conductivity of cast iron. I wonder if the poor performance of this engine could be caused by the cylinder material?--And yet Jan Ridders specifies stainless for the cylinder.

The other option is to give the cylinder more surface area to dissipate the heat, Jan's design has thick shallow grooves and thick fins which don't give much in the way of increased surface area. Use a larger dia to start with so fins can be deeper and if you use narrower groves you will be able to get more fins along the same length.

You could try modifying the one you have, grooves could easily go to 1/4" deep and add shallow ones to both ends of the cylinder which won't encroach on the slot of leg fixings

[NickG]

You’ll also notice that Poppin cylinder cover has the inside of the port countersunk or tapered to leave almost a knife edge, this is to locally make it really hot to help prevent cold air from being drawn in. What Jason said should help with longevity of runs but this engine is so sensitive. The cylinder is a big heat sink which is probably why it needs to be pre-heated.


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