Has anybody built the flame eater “Nick”?

[Brian JohnParticipant @brianjohn93961]

The cylinder is brass and the piston is bronze according to the instructions.

[Brian JohnParticipant @brianjohn93961]

I solved a few problems today. The graphite powder works well and the piston is now a very smooth fit in the cylinder, even when hot. I polished out the etch marks from the inside of the cylinder head cover as I suspected that this was causing the slider plate to stick. My assumption was correct and the slider plate is moving more freely now and never gets stuck. It still would not run so I fitted a gasket between the cylinder head and the exhaust plate just in case I did not do a good enough job getting a good fit between those two parts. I found making the cylinder head the most difficult part to make without a milling machine.

After all that, it still will not run….very close but no ! I am fresh out of ideas now.

Does the presence of the ''pop pop'' sound indicate that I have a good sealed system ?

[Brian JohnParticipant @brianjohn93961]

I have just reread the instructions to see if I may have missed something :

''When given a push the engine should diesel for another 2-3 rotations and not stop abruptly.''

My engine runs for about 10 revolutions ; I should have more friction/resistance. Tomorrow I will make another piston and see if I can get a better fit. I doubt it but at this point I will try anything.

[Ian S CParticipant @iansc]

Although the brass piston and bronze cylinder have fairly similar rates of expansion (brass slightly greater), the metals obviously work ok. Rather than oil or graphite, the best thing before a run is a wipe with a paper towel, there is a small amount of gunk left from burning meths.

I,m sticking with steel cylinders, and cast iron pistons, this combination has a lower coefficient of friction than the copper alloys.

Does the piston pass the test of sliding through the cylinder under it's own weight, then almost stopping if the end is blocked.

Ian S C

[Brian JohnParticipant @brianjohn93961]

Yes Ian, it does that but I will make a second piston anyway.

The second piston is a slightly tighter fit with better suction. This one does not drop through but it will push through so I want to try it. After a bit of mucking about with the valve settings it ran for about 15 seconds under its own power then promptly seized up. At this stage there is no graphite powder as I wanted to see how it went without it. I will let things cool off, add graphite powder and try again later.

I think flame eaters are more difficult to get going than Stirling engines : you cannot add light machine oil to the cylinder to help things along.

Edited By Brian John on 18/07/2016 09:34:14

[Brian JohnParticipant @brianjohn93961]

No…still no luck. I know it is very close but I am not sure what else I can do to tip it over the line. I might put this aside for a few weeks and move onto something else. I may get some ideas in the mean time.

Edited By Brian John on 18/07/2016 11:26:43

[Ian S CParticipant @iansc]

Can you disable the valve so it stays open?Then drive the motor at a moderate speed with an electric motor, say 2 or 300rpm for 1/2 hr, use a drop of oil on the piston, then clean the piston and bore and hook up the valve and try it, if it's still a little stiff, repeat the run in.

I agree with you that these motors are more fussy than Stirling Engines, but once it is running you'll wonder why it took so long. I'v got one of Jan Ridder's design that I built two or three years ago(might be more), it just refuses to go.

Ian S C

[Brian JohnParticipant @brianjohn93961]

Do you mean the slide valve (not the ball valve) ? Yes, that can be disconnected.

I am also thinking of trying a drop of motor oil in the piston/cylinder as this has a higher flash point than the sewing machine oil I used in the Stirling engines.

I watched a youtube video of a flame eater engine yesterday : the guy took about 10 minutes to get it going !

Edited By Brian John on 18/07/2016 13:18:10

Edited By Brian John on 18/07/2016 13:31:33

[Brian JohnParticipant @brianjohn93961]

I watched a few youtube videos today and one guy uses sewing machine oil in the cylinder of his flame eater and it runs very nicely. So I decided to try that again with no luck. I am getting an excellent seal ; it is very difficult to push the engine in reverse because the seal is so strong. I do not think the piston/cylinder fit is the problem here but I do not know what is.

I am wondering how I can turn this into a Stirling engine .

Edited By Brian John on 19/07/2016 09:46:36

[Brian JohnParticipant @brianjohn93961]

This engineer uses methyl hydrate to run his flame lickers and he rarely has to clean the cylinders at all. Have a look at his other engines. He does some nice work.

**LINK**

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian John on 19/07/2016 18:08:31:

This engineer uses methyl hydrate to run his flame lickers and he rarely has to clean the cylinders

.

**LINK**

So … what are you using ?

MichaelG.

[Brian JohnParticipant @brianjohn93961]

Yes, supposedly the same stuff but why is the inside of my cylinder contain black soot after 20 minutes ? This interferes with the smooth running of the engine by increasing the friction.

I am using the supplied fibreglass wick. I do have some Kevlar wick material on order which should be here soon. Perhaps that will make a difference.

Edited By Brian John on 19/07/2016 18:30:33

Edited By Brian John on 19/07/2016 18:32:47

[JasonBModerator @jasonb]

Brian, I thought you were using methalated spirit (metho) not Methanol

You could try it on a weak flame from your small blowlamp or a large cigarete lighter

Edited By JasonB on 19/07/2016 18:34:14

[Brian JohnParticipant @brianjohn93961]

Yes, I am using methylated spirits. I am getting a bit confused with the terminology here…sorry !

Put it this way : what could I use as fuel that will burn even cleaner and not leave sooty deposits ?

Edited By Brian John on 19/07/2016 18:35:02

[Michael GilliganParticipant @michaelgilligan61133]

Helpful quote from the Wikipedia page that I linked:

Methanol ingested in large quantities is metabolized first to formaldehyde and then to formic acid^[13] or formate salts, which are poisonous to the central nervous system and may cause blindness, coma, and death. Because of these toxic properties, methanol is frequently used as a denaturant additive for ethanol manufactured for industrial uses. This addition of methanol exempts industrial ethanol (commonly known as "denatured alcohol" or "methylated spirit" from liquor excise taxation in the US and some other countries.

MichaelG.

Edit: removed spurious smiley

Edited By Michael Gilligan on 19/07/2016 19:02:51

[JasonBModerator @jasonb]

Brian, did you see my edit before you added yours about other sources of fuel?

Chuk flame licker on gas

One running from a (large) lighter

[Ian S CParticipant @iansc]

Here is my motor after a bit of test running on the Prony Brake, it was pulling 3 inch ounces, i think it was at 200 rpm. RPM X T / 1352 = W. 200 X 3" oz / 1352 = .443 W (T = inch ounces). Ian S C

[Brian JohnParticipant @brianjohn93961]

Mr Sjani from the youtube link I posted above suggested that the ball valve might be part of the problem. The rubber ball valve is not perfectly round and there is a bit of flash or mould line around the centre. He suggested putting a 0.5mm pin through the ball so the pin sticks down the exhaust hole and this keeps the smooth area of the ball in contact with the hole…not the raised edge which would cause a bad seal.

I tried that and it has helped. I got the engine to run for 60 seconds under its own power today. That is a big improvement. I think the slider plate is still getting stuck sometimes so I need to look into that next. The engine is very sensitive to slide valve, ball valve and flame placement : all three have to be just so.

I am a bit puzzled that many youtube videos of flame eater engines say that they have to preheat the cylinder to get things going. Mine works best when cold ; the instructions confirm this.

Edited By Brian John on 20/07/2016 09:38:46

[Ian S CParticipant @iansc]

Hot, cold, they are all different, I'v heard of water cooled motors that wont start unless the water is quite hot.

That idea with the ball sound like a good one. 60 sec run, your well on the way. My first one would not run on anything but the gas torch, with the steel cylinder turning blue with the heat. To run it also had aluminium fins forced into the fins cut on the cylinder to get more cooling, then one day I tried it on meths again and it worked.

Ian S C

[Brian JohnParticipant @brianjohn93961]

I had a few more goes today but two more 60 second runs is the best I can do. The slide valve is easy to find the correct setting : 1mm of change either way and you can tell it does not like it. The ball valve has about 2mm of adjustment up and down ie. the engine will run within that range. I would not have thought it would be so hard to get this engine running because the correct settings are easy to find.

1. What else could I use as a substitute for the ball valve ? It is made of rubber and is 6mm in diameter.

2. What makes the pop sound : is it the ball valve or the slider plate ?

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Brian John on 21/07/2016 15:31:44:

1. What else could I use as a substitute for the ball valve ? It is made of rubber and is 6mm in diameter.

.

… a better quality [i.e. Ground] Nitrile Rubber ball.

Example: http://catalog.precisionassoc.com/category/precision-associates-inc-rubber-balls?&gclid=COn-mPDnhM4CFfUV0wodI6sMIQ

MichaelG.

.

P.S. … I haven't forgotten how to do hyperlinks; it's just that in the light of recent experience, "full disclosure" seems to be the safer option. Here is a link if you want it.

Edited By Michael Gilligan on 21/07/2016 16:04:13

[JasonBModerator @jasonb]

As well as a good quality Nitrile ball like Michael mentions you could also consider a steel one which won't be affected so much by temperature change.

The other thing to think about is how good a seat does the ball have to seal against? It is usual to ream the smaller hole and bore or D bit the larger seat. If you only have drilled the holes chances are the seat won't the true or round so could be a cause of leaks irrespective of how round your ball is.

Also have you made any adjustments to timing? moving th cam a few degrees either side of where you have it at the moment may be worth trying.

Edited By JasonB on 21/07/2016 16:37:33

[Brian JohnParticipant @brianjohn93961]

Jason : I have made many experiments with the timing. That is what I meant about the setting of the slide valves. It is done with the cam. Moving it from where it is now and the engine runs badly ; there is not much leeway with that. At least I know that is in the correct place.

I was already having some doubts about the seating for the ball. But before making any changes there I will try a steel ball or a Nitrile ball as suggested.

[Neil WyattModerator @neilwyatt]

Brian,

Glad you seem to be getting close to success.

My apologies for abusing moderatorial privilege, but I had to put that question mark in, it's been annoying me for weeks

Neil

[Brian JohnParticipant @brianjohn93961]

Still no luck with this : I have cleaned up the exhaust as Jason suggested. It looks much cleaner now but it has not helped. The plans only call for the hole to be drilled, not reamed so I did not have a 5H7 reamer on hand to do the job. One is on order now from HK but that will take 3-4 weeks to get here.

I called Allied Bearings this morning : they have no Nitrile balls but they will try to obtain something from ''down south'' (meaning closer to civilised areas). They did not even have a 6mm steel ball bearing…only 6.35mm. I have ordered some 6mm steel ball bearings from HK.

Who can supply Nitrile balls in the UK ?

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