Need help getting Flame eater running.

[JDYKSTRA]

I need help getting my Flame eater engine to work. It is from Bengs Modellbau. The engine has great (compression/vacuum) and I have timed it according the plans provided. The intake valve goes up to its highest point. The silicone ball which acts as the exhaust valve seems to be moving (I can hear the sound that it is moving). Can any help be provided to help in getting it running?

 

[deverett]

Sounds like you need to adjust the valve timing, assuming the cam is correctly shaped.
Try moving the cam first to close the valve later then if no success, move the cam in the other direction. I've seen it suggested that the valve needs to close no later than about 170 deg after TDC.

Dave
The Emerald Isle

 

[minh-thanh]

JDYKSTRA
Some information in the link might be useful :
https://www.homemodelenginemachinist.com/threads/philip-duclos-fire-eater.27756/

 

[rogerbh]

I need help getting my Flame eater engine to work. It is from Bengs Modellbau. The engine has great (compression/vacuum) and I have timed it according the plans provided. The intake valve goes up to its highest point. The silicone ball which acts as the exhaust valve seems to be moving (I can hear the sound that it is moving). Can any help be provided to help in getting it running?

I have the same Bengs Modellbau flame eater and never did get it to work, it now sits on a shelf in the workshop daring me to have another go at it.

 

[Steamchick]

I have a cheap Chinese flame eater... worked the first time, then stopped, and it hasn't worked since! - I found the timing had slipped, so that's why it stopped, But I have read they are sensitive to valve timing and friction, Then I oiled it and read that when oiled they have too much drag so can't run... so mine lives on the shelf. A very pretty ornament. - I am drinking the meths and using the oil lamp for lighting... Kon pay!

 

[BaronJ]

Hi Guys,

I'm using the lamp oil as cutting lubrication, nice smell, citronella perfume, it works very well and its cheap compared to WD40 and the like.

 

[coulsea]

i think that the bengs use graphite pistons in which case don't use oil. friction and flame position are important. try to use the blue part of the flame and make sure the valve moves freely. even the bearings can stop it from running, wash them out with petrol to remove any grease. methylated spirit in the burner not lamp oil. the silicone ball should be only to prevent compression at the top of the up stroke, it has to seal perfectly so make sure that the seat is smooth.
it sometimes helps to have the flame slightly to one side, i think that the blue part of the flame is fuel rich and adding a bit of air at the side means that it will burn after that valve has closed and produce more vacuum.
good luck

 

[Ken I]

"I have a cheap Chinese flame eater" me too :-

Actually I'm quite impressed with it - came with a set of allen keys, 2 spare valve blades and a spare wick.
I played with the valve timing and found it was set correctly and wasn't too fussed about it - however a while back it stopped working and I discovered one of the flywheels had come loose - insufficient inertia to keep it going.

It doesn't run "cold" and requires a lot of spin starting to draw the flame in and get some temperature into the cylinder (strange I would have thought it would work best cold) - so I typically pre-heat the cylinder with a butane torch first - to save on all that mucking about.

Very fussy about friction as I have discovered on other flame licker and stirling engines.

Regards - Ken

 

[Steamchick]

I have been sticking to flame licked burgers.... waistline now bigger!
Theoretically, the blue flame isn't so hot, but you are right about a bit of air may give a tiny continuation of combustion in the cylinder. However, the glowing "yellow hot" carbon in the yellow flame may have more heat at entering the chamber, although short of air will not be burning to CO. Other te9xptsp have recommended the yellow flame as the carbon lubricates the bore... ? I don't know as mine doesn't run. What is an optimum valve timing?
Ta,
K

 

[BaronJ]

I have been sticking to flame licked burgers.... waistline now bigger!

I don't know as mine doesn't run. What is an optimum valve timing?
Ta,
K

One that works

 

[Steamchick]

hi baron. Not found that one yet.
K

 

[BaronJ]

Hi K,

The gate should open 10 to 15 degrees before TDC and close about 30 degrees after TDC.

Copied from a German web site.

 

[coulsea]

from my experience valve timing should be close just before BDC and open a bit more before TDC. air in the cylinder cools very quickly which is why some engines need preheating, the air has already significantly cooled before the valve closes. As for carbon in the flame i always use a fiberglass wick because carbon will gum up the works. Listen to what the engine is doing, with no flame it will produce compression on the up stroke which you can hear when the valve opens, with the flame introduced that compression should reduce and when the flame is right it will change to vacuum. once you get a flame licker going you get the feel and sound of how it should be and you wonder why you had so much trouble.

 

[Steamchick]

Thanks Baron & Coulsea. I'll have another go soon. On my model, the valve timing slipped after just a few seconds of running (the first time out of the box), so I believe it will run... just fine tuning the valve timing and flame to get it right. Or I'll drink another bottle of alcohol and ponder it awhile...
K

 

[olympic]

I, too, have a flame-eater. Made it myself. I think it looks all right, and that's good, because it doesn't run at all.

 

[Steamchick]

Aha! An oiler on the cylinder. By all accounts, oil in cylinders kills flame eaters! A chap in the local club has some good runners, he says let them be lubricated by the carbon from the flame -without oil. Even the lightest oil has too much drag for these gnat powered engines.
These gnat-powered engines were originally powered by huge coal fired furnaces that were used to smelt iron. The flame zone was connected to the flame eaters so they could power the compressor-blowers that forced the fires in the furnaces. But they wore badly from the coarse grinding from the coal ash ingested in the smoke. Still, the flames from the smelting process were a free source of heat, and thus the first "direct combustion" engines, without a steam plant. Later, they figured out how to burn oil fuels inside the cylinders... and that's another story. Really, these atmospheric engines were the combustion equivalent of Newcomen's engine for steam power.
I find the history interesting.
Any more?
K

 

[minh-thanh]

I, too, have a flame-eater. Made it myself. I think it looks all right, and that's good, because it doesn't run at all.

Try replacing a thinner valve

 

[olympic]

Right now it's .002"; hard to get much thinner.

I have replaced the bushings with ball bearings, made two or three pistons of different materials, fiddled with the timing, and done a thousand things you have not dreamed of. Still no joy.

Next on the list is a graphite piston....

 

[minh-thanh]

I have replaced the bushings with ball bearings, made two or three pistons of different materials,
Next on the list is a graphite piston....

With bearings: did you clean the ball bearing grease ??
Before you change the piston material: Make sure your cylinder is straight and smooth ( like polish )
if not, the cylinder cannot be airtight with any piston of any material and it will damage the graphite piston faster.

 

[Jeffro]

I made a Bengs "Big Nick" Took a while to get it to run and found the exhaust rubber ball was bouncing and not sealing for the intake stroke. Reduced its free travel and the engine has run great ever since, and with light weight oil lube. please note how free these things need to be and still have a very good piston fit. Youtube available and 4 minutes of your life spent if this link works. myshed67

Cheers
Peter