Flame Licker Problem

[Steve]

Can someone please help on this problem i have on a scratch built Flame licker Engine ......... It will not run at all ...... The cylinder is castiron..... 1 inch bore ..... 2.5 inch long ...... Piston Is castiron ....Stroke 1.8 inch.... The timing is correct , working from BDC ...... Valve closing just before BDC and open before TDC ...I have tried different positions of the timming.... Its all fully Ball raced and with a slide vale on the side....... And runs very freely ...... When i put the methes burner by the inlet hole and spin the flywheel , it just blows out the flame............. I have tried all positions with the Meths burner , but no luck ........ I have even made a new piston in brass just to see if that would any diffrence but to no avail .......... This is my first attempt at making a Flame licker ......... Please help as i want to build other flame licker engines , but with this one not working tends to put a cloud on the project.

Please HELP .......Thanks

Steve

 

[mklotz]

It's hard to diagnose from a distance but here are a few things to try:

Preheat the cylinder with the alcohol lamp. If it's cold it will "quench" the hot gas before the valve has a chance to close, thus losing the vacuum needed to make the engine work. Preheat the valve flapper as well.

Lubricate the piston with some dry graphite. These engines have miniscule specific power and need all the help they can get.

Try an alcohol lamp with a thicker wick in the fond hope that it won't be blown out. Move the lamp back a bit from the cylinder opening. The hottest gas is not at the base of the flame but rather up nearer the top of the visible flame.

 

[Mcgyver]

as Marv says, there's very little power. in addition to his suggestions, minimize the weight of components that change direction - very thin walled piston, AL connecting rod etc will help. I lapped the bore on mine to a mirror finish - using a lap instead of hone gives you chance to get the bore truly straight and round as well.... rough finish on the bore or 'tight' spots could affect it. I've found after a couple of heat and sterling (in other words low power) engines that what you want an effortless sliding fit between a highly finished bore and piston yet with minimal clearance so power is not lost.

 

[IronHorse]

Another thing to try is to rotate the flywheel in the opposite direction. There should be a fair amount of compression if the valve is sealing properly. Rotating the other way should produce a whistling sound as the air is forced thru the valve (reed type). Low friction and good valve sealing and she should run.

 

[NickG]

I'm not trying to be funny here, but is it actually blowing the flame out? If it is, the flywheel is being rotated the wrong way! The piston should be on the down stroke away from TDC when the valve is open to suck the flame in. I don't think for one minute you haven't thought of this but I've done equally as silly things!

Nick

 

[Steve]

Hi Chaps and thankyou for your replies ....... I made this flame licker engine by looking at other designs and ideas . I know that there isn't much power produced by this kind of engine........... I didn't polish the bore , but it is very smooth , but not like glass ......... I have made most of the moving parts as light as possible ....... When i say it blows the flame out , i mean when its on its up stroke from BTC ..... pushing the air past the valve ....... If it helps i could take a video of it and post it showing what the engine is doing ..

Many Thanks

Steve

 

[NickG]

Steve, it might help if you could post a video up. Does the piston try to pull back at all when it gets over BDC?

How much dead space is there in the cylinder? That's the only other thing I can think of, if there's too much dead space that isn't being swept by the piston.

I think as marv says though, it could be just the position of the flame. Don't know whether you've seen it but Jan ridders has done a bit of a study on flame position and has come up with what he thinks is optimum position for his. Quite interesting as it's not really where you'd expect it!

 

[rake60]

Flame Lickers are my favorite engines.
They are also my most hated engines! :

For mine I find the valve closing 45 to 55 degrees BEFORE bottom dead center works well.
You need to get the heat in, but it needs sufficient time to cool to keep the engine moving.

If it's blowing the flame out, you have forward pressure in the cylinder.
In a running condition there might be a little of that, but there shouldn't be a lot.

Watch the flame in this video of my Poppin running.
You will see a little bit of disturbance on the forward stroke, but not much.
[ame]http://www.youtube.com/watch?v=TjEcWoxITSE[/ame]

I'd suggest you re-time your engine so the valve closes sooner in the stroke.

Rick

 

[Mcgyver]

my own contribution to fire eating engine technology is the magnetic fuel tank. The difference between running and not is the tiniest adjustment of flame position; yet you don't want the tank and flame just sitting loose on the base. So i bored out a small section of the tank and epoxied in a rare earth magnet, and bored out a section of base and epoxied in a slug of steel -works very well.....if yours doesn't have the ability to adjust position consider this, operation is very sensitive (like down to an 1/8 or 3/16") to position. With all this flame eater talk, ran mine last night. ticked along at about 200 rpm on methyl hydrate....keep at it, you'll get it going

 

[Stan]

When discussing flame lickers, I have repeatedly said that the flame position is the most critical part of the design. In this case I would suggest that the burner wick is too high. In normal operation the flame will move when the engine is running but if the flame is positioned so that expelled air can hit the flame low down, it will blow out.

My success with flame lickers has been with the wick either positioned below the valve or behind it (toward the flywheel). In either case have a long flame so that the engine can suck flame from the upper part of the flame.

 

[b.lindsey]

Steve, I'm not sure what your design is, mine is the Duclos design like the one Mcgyver shows. I just looked at the timing also and agree with Rake that the slide valve closes about 45 degrees before BDC and is just beginning to open again at or just past TDC. They can be finiky for sure but don't give up...they are well worth the time to get them running.

Bill

 

[Jadecy]

It took me a while to get my little blazer running. One of the first issues I had was the burner. It kept blowing out. Most of you know these things I'm about to say but it was my first flame eater engine and my first experience with an alcohol burner.

1.) I was using the wrong fuel. I grabbed some rubbing alcohol from the bathroom in my haste to try my engine out and see if it would even try to run. I later found that that rubbing alcohol was some low percentage of alcohol diluted with water.

I went to wal-mart and found the highest percent alcohol mix I could find in the grug section.

2.) I was trying to use a wick made from some string I had laying around. What an irritation. It all apeared to have nylon in it.

At wal-mart in the sewing/craft section they have small balls of 100% cotton yarn.

At home I cut a piece fairly long and kept doubling it until it fit snug in the burner mouth. I left a fair amount to sit in the bottom of the burner and soak up the alcohol. My burner stays lit very well now.

3.) It sounds like you got it freed up real well. You said you based it on a design but did not build from plans. How did you determine flywheel size and material? I talked to someone at a show earlier this year that had 2 really good runners and he showed me some flywheels that he used in experimentation. He said the flywheel size and weight are very critical. When he put a steel flywheel on in place of the aluminum one (the steel one was cut down to adjust for weight) he had a real time getting it running. The inertia due to different weight distribution was difficult to figure out.

4.) I fought with mine for over 2.5 weeks off and on. I finally scrapped the aluminum cylinder, Turned a new cylinder out of aluminum and sleeved it with brass tubing. I then had to create a new piston to fit the new cylinder. I used cast iron for the piston.

I had what I thought was a miniscule resitant spot as the piston moved up and down and the engine would not run. I polished the cylinder with a rag and brasso brass cleaner, coated the piston with graphite (scribbled with no. 2 pencil) and tried running the engine again.

It still wouldn't run but at least it tried to.

The last thing I chaged was the valve. The spring steel was holding the valve down too hard. I also had to adjust the tab to get it to hold the valve flat on the cylinder. The other thing I did was lap the valve to the cylinder and scribble on it with a bencil to lubricate the sliding surfaces.

Now the thing runs like a champ but I still have to clean out the carbon in the cylinder with alcohol and lubricate with graphite after each run.

Any suggestions on a better fuel than rubbing alcohol?

 

[mklotz]

The alcohol I use is just the bogstandard shellac thinner sold by the quart in places like Lowes, Home Depot, etc.. Seems to work fine. HD sells naphtha (Zippo style lighter fluid) as well. I've never tried it on a flame-sucker but it might work. Like alcohol, it burns quite cleanly.

A standard mop - the old style with lots of individual strands - will provide a lifetime's worth of wicking material. Also, stores that cater to the camping out crowd still sell wicks for kerosene lamps. Ace Hardware still sells same in my area.

 

[Steve]

Hi Guys ....... Can i First say a very BIG Thankyou to everyone for the info ........ And its been a very big help ...... And i have got the engine to run ....... As theres not much in a flame licker engine , i looked at the piston and it did feel a bit heavy , so i machined it making the piston wall to 1mm thick ...... I also replaced conrod , making it thinner .......... I put it all back together and fired it up ......... I noticed it tried to run , so i adjusted the timing and Hey Presto it Ran ...I was so so Happy.... The flame blowing out is still there , but its because i was putting the wick right in front of the fire hole ...... Now the wick is about 1/4 inch below the fire hole and the engine runs fine and it don't blow out ........ As this is my first attempt at a flame licker engine i will take a video of it and post it very soon .......

Thankyou so so much.

Steve

 

[Mcgyver]

hey congrats, glad you got it running

 

[Maryak]

Steve,

Congratulations on a successful runner

Best Regards
Bob

 

[dsquire]

Steve :bow: :bow:

congrats on getting the flame licker running. I can imagine how happy you are seeing as this is your first one. I'll be watching for the video when you get it posted.

cheers

Don

 

[NickG]

Steve, excellent news! I am envious, that is my next project!

 

[b.lindsey]

That's great news Steve. Looking forward to the video as well !!
Bill

 

[rake60]

Congrats Steve!

I'm looking forward the the video.

Rick