Has anybody built the flame eater “Nick”?

[Brian JohnParticipant @brianjohn93961]

Update : with a sharp scalpel I trimmed away as much flash as I could from the ball valve and it ran for a full two minutes before stopping. Why does it stop ? If it runs for 2 minutes than surely it should be capable of running for 15 minutes ! My only conclusion is that as the ball bounces around it eventually ends up in a position that is not giving a good seal. Bring on the Nitrile balls !

[Neil WyattModerator @neilwyatt]

Posted by Brian John on 23/07/2016 07:39:56:

They did not even have a 6mm steel ball bearing…only 6.35mm.

Blame Bon Scott, I believe its his fault that Australia has big balls.

Neil

[Brian JohnParticipant @brianjohn93961]

But anyway, I might give the 6.35mm balls a go on Monday. Anything is worth a try with these fussy engines.

Who can supply Nitrile balls in the UK ?

 

 

Edited By Brian John on 23/07/2016 09:05:07

[Brian JohnParticipant @brianjohn93961]

Today the engine ran for 5 minutes …then it blew the flame out and would not run again after that. I do not know if I should call that a success or not ? If the flame is too big then the engine will not run at all. If the flame is too small then then engine can blow it out.

Tomorrow I will try the 6.35mm steel ball and hopefully the Kevlar wick material will arrive too so I can improve the meths burner flame.

[JasonBModerator @jasonb]

If the engine is blowing out the flame then the valve may be opening too soon while the piston is still mobing towards the head.

[Ian S CParticipant @iansc]

It is possible that the wick tube is a bit too high, it's best that the flame is a bit below the inlet, although in this design all the exhaust should go up the exhaust pipe. My motors use the same hole for inlet, and exhaust. I wonder if you are getting a bit of valve bounce, and it is blowing out through the inlet. Some times the motor will/may oscillate, not do a complete rev, but go back and forth at quite a good rate.

Ian S C

[Brian JohnParticipant @brianjohn93961]

I have already trimmed a few mm of the wick nozzle but I might have to take off a bit more. The burner really is not suitable for this engine. It was probably designed for another engine hence the vertical adjustment. I want it lower…not higher !

[JasonBModerator @jasonb]

It seems to suit all the ones you see running on youtube?

[Brian JohnParticipant @brianjohn93961]

Actually no : if you search for ''Bengs Nick flame eater'' then in all those videos that are listed the engine is different or the burner is different. The closest one I can find to my engine /burner setup is Mr Sjani and he has put a hood over his engine to trap the flame. You might be getting different search results to me.

**LINK**

The hood is actually a very good idea…I had not noticed that before. I will have a look at doing that tomorrow as it should be simple enough. And perhaps taking a few more mm off the wick nozzle while I am at it.

[JasonBModerator @jasonb]

Beng's own video is of a standard burner and engine and that runs even when the burner is raised up so can't see why it would need to go lower.

Small Nick on the left here also standard or this one

Just search for "Beng's Nick" or "Nick Von Bengs"

 

Edited By JasonB on 24/07/2016 15:16:09

[Brian JohnParticipant @brianjohn93961]

Interesting : and they seem to be in the half raised position too. If I were to do that with mine it would be far too high. I am not sure what is going on there. I must have another look at my burner.

He was using the oiler in that first video so it is good to know I am not the only one who needs a drop or two of oil on the piston. I wish I had installed the oiler now. I left it out thinking that it was just for show ; the instructions were quite insistent that the piston be run dry or perhaps with a bit of graphite.

[Brian JohnParticipant @brianjohn93961]

I tried a 6mm and 6.35mm steel ball bearing today but it would not run at all : I guess it is too heavy. Allied Bearings have not yet sourced a 6mm Nitrile ball for me here in Australia so I will have to start looking overseas.

I did have another 5 minute run today but then it just slowed down and stopped as usual. This time the flame had not gone out. It sounds like it starts to ''miss'' before it fails. I know ''missing'' is the wrong term as there is no ignition in this engine but just as everything is running well you can hear that the pop sound disappears for a couple of strokes.

Does that tell anybody anything ?

[Ian S CParticipant @iansc]

The only thing I can think of with the motor missing would be valve spring strength. All the moving parts of the valve train need to be well lubed, also the valve needs to be very free in it's slot, it can have plenty of clearance the vacuum will hold it against the head. On my motor the head and the valve are both cast iron, lapped together so it doesn't leak. You say the popping stops at times, maybe the valve is staying open.

The steel balls probably are too heavy.

Ian S C

[Ian S CParticipant @iansc]

Brian, you might get rubber balls a somewhere like Bunnings, or some place that sells parts for garden sprayers.

Ian S C

[Brian JohnParticipant @brianjohn93961]

The instructions specifically say NOT to oil the slide valves because this may cause the engine to run hard and seize. But then they say not to oil the cylinder/piston either ! Up until now I have not oiled the valves but I might give that a go tomorrow. I could increase the strength of the spring by putting a shim under the base of the spring where it rests on the aluminium plate.

Garden sprayers…you mean lawn sprinklers ? Do they use ball valves ?

Edited By Brian John on 25/07/2016 17:59:10

[Brian JohnParticipant @brianjohn93961]

I oiled the slide valve bearings today and it ran for 10 minutes before stopping. The flame did not go out. I do not know if oiling the slide valves helped or not.

What is the purpose of the rubber O ring on the slide valve rod bearing ? I have removed it because it just keeps coming off. It makes the engine a bit noisier but it certainly runs more freely without the O ring. Is the O ring to make it quieter or to slow the engine down so it does not run too hard. The instructions seem quite concerned about the engine running too hard.

I will make this part again when the new bearings arrive from HK. I will make the groove deeper so the O ring stays in place.

Edited By Brian John on 26/07/2016 09:06:27

[Ian S CParticipant @iansc]

Brian, is that the O ring that rolls on the wheel against the cam? If so all that taking it off will do is slightly alter the closing of the valve, and as long as the valve covers the hole all is OK. Both of my working motors have steel rollers, I have never thought of putting a rubber tire on, so I don't know if it would be quieter.

I don't think oil would be much use on the sliding part of the valve against the head, it would soon get burnt off, and the residue could gum up the works.

Yes it might be worth shimming up the spring, I'm forever fiddling about with my motors— thats why I build them, probably the reason I don't build them to look pretty.

The balls are in spray pumps. You can usually get spare parts for these things. Could be at a garden center, do they have them in Cairns.

Did you make the exhaust pipe the same length as the plan, the length could/might alter the tune of the motor, too long might slow things down a bit.

Ian S C

Edited By Ian S C on 26/07/2016 10:39:33

[Brian JohnParticipant @brianjohn93961]

Yes, the O ring rubs against the cam. I am really not sure why it is there.

When I say I oiled the slide valves, I meant the axle supports for the slide valve axle. The instructions say NOT to do this. They seem overly concerned about the engine running hard whereas I am more concerned about the engine running at all !

We have garden centres but the chances of them having spare parts for anything is very unlikely. I will ask tomorrow.

Allied Bearings could not find a 6mm Nitrile or Viton ball for me anywhere so I am not sure where else to look in Australia. I might have to buy it from the US but their postage rates are often quite high even for small things.

[HopperParticipant @hopper]

Shampoo pump bottles and household cleaner spray bottle quite often have a small plastic ball inside that acts as the one-way valve for the pump. Whether it would be up to the task in a hot environment, there is only one way to find out. I usually pull them apart when they are empty and keep the springs. I might have a ball somewhere in the shed, but god only knows where.

There are some on eBay Aust. but from the US. $1 for a 6mm ball, $20 for the shipping. Yikes! But you can often contact the seller and get them to sort a better shipping deal than what eBay's auto shipping calculator says. Check this out  http://www.ebay.com.au/itm/Black-Nitrile-Ball-4mm-15mm-Price-Per-1-/231974274293?var=&hash=item3602be84f5:i:231974274293

Edited By Hopper on 26/07/2016 11:48:34

[Brian JohnParticipant @brianjohn93961]

The ball really needs to be rubber or synthetic rubber as I doubt plastic would stand the heat. The exhaust system does get hot : I have burnt myself a few times so I know !

I will have another look at ebay. I was not aware that postage was negotiable.

I am not having much luck on Ali Express either. I thought you could buy anything from there. What is another name for a ball (valve) ?

Aha…Alibaba has plenty !

 

 

Edited By Brian John on 26/07/2016 14:37:32

[Ian S CParticipant @iansc]

I just put "wanted to buy 6 mm rubber ball Australia" in Google, if you get to Alibaba, they cost less than 1 cent each, but you have to buy them by the thousands, the ones you want are ground to shape, you can get them suitable for high temperature.

Paint spray cans have wee glass balls, don't know the size.

Ian S C

[Brian JohnParticipant @brianjohn93961]

That ebay company listed above said they cannot reduce the ebay postage cost but they directed me to their website (Painful Pleasures) which has both Nitrile and Silicone balls for sale. I have ordered three of each in both 6mm and 8mm sizes ; the total postage to Australia is only $8.

**LINK**

I have read the instructions again today and they said the engine should run for 10-15 minutes before it gets too hot and stops. I am guessing 15 minutes is during a German winter with the windows open ! I can get 10 minutes from this engine so that may be all it will do. If I can get it to do that every time then I will be happy.

NOTE : there is always somebody selling what you want but even with Google and the internet they can be hard to find.

 

Edited By Brian John on 27/07/2016 18:25:51

[Ian S CParticipant @iansc]

Ran both my engines today, the older/smaller one ran two runs of 17 minutes/ 10 ml of meths per run, the larger one, built earler in the year ran flat out for about 5 minutes, then struggled for the next 5 minutes/ 10 ml meths.

I might make a little fan for the big one, it should go as long as there is a flame.

I suspect with all the brass on your motor, a 10 minute run would be fair enough, it might be possible to fit a fan driven from the crankshaft with a rubber band and a couple of pulleys. You just have to work out a way of doing it without blowing out the flame.

Ian S C

[Brian JohnParticipant @brianjohn93961]

Do you think a fan would really help ? I will think how I can do that : something small facing side-on should not cause any problems.

My main priority at the moment is to get some consistency with the engine. I want it to run for 10 minutes every time…not just when it feels like it ! I am hopeful that when the new Nitrile and Silicone balls arrive from the US then things should improve.

[Ian S CParticipant @iansc]

Yes I think you might be right about it going better with the new balls.

Spent a while this after noon fiddling around with an old muffin fan that was on the radiator of one of my Stirling Engines until it got a bit of over voltage, and died. I extended the spindle out the back so I could fit a pulley, so far I have left the magnet and core inside, and bought out a couple of wires, so far I have a little breeze, and not quite 1 volt. I think the alternator idea can go, there will be a lot less drag, so I will be able to speed it up a bit more. The motor needs a shroud around it to direct the air flow, cardboard will do for a start, but I'll need to move the fuel tank.

Ian S C

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