Announcement

Collapse
No announcement yet.

Brian does Ridders flame eater

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • aostling
    replied
    Originally posted by brian Rupnow View Post
    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?--
    The performance has to suffer from the relatively high thermal resistance of SS compared to cast iron. In fact, why not make the cylinder out of aluminum?

    I hope you can still find an icicle, now that summer is here (in Phoenix, at least). What happens when you drape one of those across the cooling fins?

    Leave a comment:


  • brian Rupnow
    replied
    I want a dependable flame eater style engine. I modelled Mr. Senfts "poppin" engine today---
    Last edited by brian Rupnow; 03-11-2018, 08:28 PM.

    Leave a comment:


  • The Artful Bodger
    replied
    Brian, it seems this little engine operates on very fine margins!

    Leave a comment:


  • danlb
    replied
    A little internet searching shows that "stainless" covers a range of thermal conductivity, with 316 being in the middle of the range. I wonder if a different alloy was used by Ridder.


    Dan

    Leave a comment:


  • sid pileski
    replied
    My atmospheric engine uses a stainless cylinder and a graphite piston without any issues I think you must have something else going on. Keep at it OD you’ll get it.

    Leave a comment:


  • brian Rupnow
    replied
    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.

    Leave a comment:


  • brian Rupnow
    replied
    Yes Sparky, it does meet all of the requirements as set down by Jan Ridders, and it does run. It runs on methyl hydrate and it runs on 99% alcohol from the pharmacy. It does not start consistently, and once running it doesn't stay running consistently. It may be a proven design, but many others who have built this engine have either had the same results as myself, or been unable to get the engine to run at all. It was a fast and interesting build, but I'm not impressed. I have many other types of engine "under my belt", but had never built a flame licker before. I don't think I would advise someone to build this engine. If I had it to do again I would probably favour the "Poppin" engine, which seems to be much more forgiving.

    Leave a comment:


  • Sparky_NY
    replied
    Originally posted by brian Rupnow View Post
    Things are reassembled with the machineable graphite valve and piston. I hate to say it, but the engine is no different now than it was with the cast iron valve and piston. It spins very freely, it acts as if it wants to run, but it is very difficult to find that "sweet spot" where it will pick up and keep on running by itself. I know that if you do find that "sweet spot" the engine will set there and tick over beautifully for about 20 minutes until the cylinder heats up to a point where there isn't enough temperature differential to keep it running. I may dick around a bit with different fuels, but unless changing to a hotter fuel does something remarkable, I'm done with this engine.
    When you say it "spins very freely" , does it meet the very specific tests that are given on Ridders website for the engine? He goes into great detail and its gives very specific measurements of how free the engine should spin. He also is very specific about recommended fuels. Its a well proven design so the problem does not lie there.

    Leave a comment:


  • bob_s
    replied
    Yes.

    Leave a comment:


  • BCRider
    replied
    Makes me think that a thin stainless sleeve to aid with avoiding any corrosion from condensation with an aluminium cooling jacket would be a nice option. Much like a model airplane engine has a steel liner in a finned casting. But in this case I'd likely shrink the jacket to the liner.

    Thoughts?

    Leave a comment:


  • bob_s
    replied
    316 stainless steel has about one third the thermal conductivity of plain carbon steel or cast iron.
    10 vs 30 Btu/(hr-ft-F)

    Leave a comment:


  • brian Rupnow
    replied
    Things are reassembled with the machineable graphite valve and piston. I hate to say it, but the engine is no different now than it was with the cast iron valve and piston. It spins very freely, it acts as if it wants to run, but it is very difficult to find that "sweet spot" where it will pick up and keep on running by itself. I know that if you do find that "sweet spot" the engine will set there and tick over beautifully for about 20 minutes until the cylinder heats up to a point where there isn't enough temperature differential to keep it running. I may dick around a bit with different fuels, but unless changing to a hotter fuel does something remarkable, I'm done with this engine.

    Leave a comment:


  • brian Rupnow
    replied
    My machineable graphite came in this morning, so I immediately took it into the machine-shop and made a piston and a valve. It is incredibly filthy stuff, as the picture testifies, but machines very easy. Everything I had read about machineable graphite recommends using carbide tooling to cut it, and maybe for a great deal of machining this may be so. For the little bit of machining I had to do, HSS tooling worked fine.

    Leave a comment:


  • brian Rupnow
    replied
    I had to go out for an hour this morning.--Wouldn't you know it, when I got back, there was a note on my door from FedEx, saying that no-one was home to receive the shipment, but they would try again tomorrow!!! I'm thinking that is my stick of machinable graphite.

    Leave a comment:


  • mygrizzly1022
    replied
    Originally posted by brian Rupnow View Post
    I have never thought about a power drawbar for my machine. Sorry, if I had any ideas on it I would certainly share them.---Brian
    Brian

    No need to apologize, no problem! Ive scattered a seed and who knows it may very well germinate.

    Leave a comment:

Working...
X