Flame Gulper not working.

[arjc]

Hi guys, first post on here,

Over the past few weeks i've been making a flame gulper engine, but after assembly today, i'm struggling to get it to work. i've attached a video, in which i have it rotating by hand.

It's a Jan Ridders design, but unfortunately, when searching for plans i must have found some really old copies, and i had to figure out some dimensions myself.

Thanks for any light you can shed. cheers!

View My Video

sorry that the video is upside down.

 

[Cogsy]

Hello and welcome to the forum.

I have made this engine (it was my first) and I understand how tricky they can be to get running. The first thing is to make sure it's as frictionless as you can make it, the bore is straight (no taper) and the piston and valves seal well.

If you pass all those tests then make sure your valve is set so it can't travel far down the bore past the point that it closes the port or you will be robbing the engine of power. Also set it so it doesn't move excessively past the 'fully open' position, nor restrict the piston from getting to top dead centre, as again you will be losing some of your much needed power.

Finally, a good flame is essential and flame position is critical on this engine. I can move the flame a couple of mm's and go from running fine to not running at all. My best position is with the wick hard against the cylinder and to the front of the port, roughly half covering the port.

I'm sure you'll get it to go but it can take some time. Good luck and let us know how you go.

Here's a video of mine running. About half-way through you can see the effect of a tiny flame position adjustment.

[ame]https://www.youtube.com/watch?v=RsqjzybN9Pc[/ame]

 

[portlandron]

Like Codsy has stated every thing need to move as free as possible. Don't use oil. I use powdered graphite. If there are any bearing that have shields on them remove the shields and wash the bearing in alcohol to remove all grease.
Preheating the cylinder may help.
From the video it's hard to till but it does not look like the flame is being pulled into the cylinder. If that is the case then you have cylinder/piston clearance problem, to much. When you pull the piston out of the cylinder and the valve is closed you should have resistance, from the vacuum, and hear a pop.

 

[arjc]

Righto. I'm going to be making a new piston and valve. what sort of tolerances did you use between piston/valve and cylinder?

Thanks for the help!

 

[portlandron]

Don't recall what the tolerances were but recall reading someplace that the piston should be a close enough fit that it will not fall out of the cylinder, under it's own weight, when the valve is closed.

 

[arjc]

Right. got back on it this morning,
1. Piston wont fall out on it's own weight. ( and there's a loudish pop when you pull it).
2. I've reduced the weight of everything, piston and valve have walls of 1mm, the conrod is already less than a mm thick, and the valve mechanism has been reduced to 1.6mm wire.
3. now using graphite to lubricate it.

But, it's still not working.

Is meths an ok fuel to use? because that's what i'm using.

Cheers, Alex.

 

[Cogsy]

Should be fine, that's what I use. Are your bearings open type (no seals or shields)? Have you rinsed out any oil or grease in them? There's a trouble shooting section for this engine on Jan's site which should help you work out if your friction level is ok. Click here -it's at the bottom of the page. There is a button to convert the page to English if it comes up in Dutch.

 

[arjc]

All my bearings are open bearings.

I've just seen something that might be the cause. the gas seems to jet out of the cylinder port when the piston moves toward it, and I've seen elsewhere that it shouldn't do this. is there a cause for this? i've just checked the tolerances, and i'm down to 0.015mm a side.

Here's a couple more video's:

(i apologize in advance for the horrendous re sizing of Tinypic if you want a better quality video, i'll change it)

This is a friction test. it rotates 10-15 times before slowing down.
View My Video

This is what the flame does.
View My Video

 

[Cogsy]

The video quality is a little rough, and both links were for the friction test only. It's hard to tell but it looks like the friction test was with just the piston and not the valve? If it was, Jan suggests it should spin for around 15-20 seconds. With the valve connected as well it should run for 5-8 seconds, and just the flywheel on it's own should spin for 1.5 - 2 minutes. I couldn't quite get to those standards with my build (Jan is renowned for getting super low friction) but I got reasonably close. If your video is without the valve then it is possible you may still have a little too much friction. It could be as simple as a slightly misaligned conrod connection.

As to the flame, I haven't been able to view the video, but it is normal for the flame to 'spurt' a little as the valve opens and the piston is finishing it's upward stroke, but if it's blowing anything out the port while the valve is shut then your valve is leaking and that will definitely keep it from running.

One thing to take note of, does it try and run? Like does it spin noticably longer with the flame than without, or is there no real difference?

 

[Omnimill]

My Jan Ridders took ages to get going. I always ensure it's lubricated with Graphite and pre heat the cylinder with a hot air gun. Flame position is crucial, or it is on mine anyway. I'd have to disagree about ordinary (purple) meths, I don't think it burns hot enough to run my engine so I got some 99% denatured Alcohol (industrial meths) for mine and it starts easier.

http://i230.photobucket.com/albums/ee286/Arbalist/M2-Computer.mp4

 

[portlandron]

I agree with Ominimill about the fuel. Don't use plan Rubbing Alcohol it produces to much water vapor which makes the valve stick. I use only Denatured Alcohol, which you can get a most good paint stores.

Don't get discouraged sometimes it's more work getting an engine running then it is machining the parts.

 

[Cogsy]

I've never heard of 'purple' meths before, possibly we have run into a difference between our parts of the world. Normal meths here works fine but I think it's strength is only around 96.5%.

Your engine looks to run perfectly Omni, and I agree they are a bear to get going and flame position is critical.

Arjc - your engine looks to be the first version of the plans, mine is the second, so there are differences, but looking at your first video again I can see right through the port and out the end of the cylinder at times. On my version this is never possibly as either the valve is covering the port or it's at the top of the cylinder. To be able to see through that area, my valve would have to be going way too deep into the cylinder. As I said, your design is a bit different to mine so it may be ok but you might want to check it.

 

[arjc]

The valve wasn't connected in the video.

Thanks for all the info! i've been looking at quite a few over these engines over the past couple days. are the valve and piston diameter critical? mine seem to be lots bigger than alot of them. they measure out to be 22mm. Some plans i have just found say they need to be 20.

 

[Cogsy]

I think the original plans say 18mm for the valve and piston but the revision says 22mm for extra power so yours should be fine.

 

[arjc]

Yo.

Got hold of some powdered graphite today from work. applied that and still no avail. also increased the flywheel size, akin to the later designs.

IS the Cylinder port size Critical? what size are the ones on your engines?

another video here, from all angles. Still upside down though. seems to be my phone. this one is higher quality though!

http://videobam.com/JVktr#

If anyone has any more suggestions, or something that looks out of place, please let me know.

Cheers, Alex.

 

[Cogsy]

Not sure that the port size is overly critical, I know mine is set back a little further than it was supposed to be.

Video looks good, it actually looks like it's close to running. The blackness around the port is a little strange to me though. I don't get much/any soot build up around the port. You might have some built up in the cylinder so I'd give it a good clean. Not sure if I mentioned it before, but my wick has to be hard up against the cylinder, slightly forward to the port. If it's not touching the cylinder then the engine sucks cold air and it won't go.

At this stage I'd just keep trying different flame positions a couple of mm at a time. Mine is literally that sensitive to flame position. Good luck.

 

[Blogwitch]

I built the very first one to be shown on here, so if you read these two posts through it should give you some idea of how to get it going.

http://www.homemodelenginemachinist.com/showthread.php?t=184&highlight=boxer+flame+licker

http://www.homemodelenginemachinist.com/showthread.php?t=293&highlight=twin+flame+licker

The pictures from the original posts are now long gone, but the text says it all, plus the video in the first link is still working, and here is the link to the finished engine.

https://www.youtube.com/v/Kc8C12QrrRI

It still runs perfectly even today with just a slight warm up and definitely NO LUBE in the cylinder at all.

 

[Swifty]

I've never heard of 'purple' meths before, possibly we have run into a difference between our parts of the world. Normal meths here works fine but I think it's strength is only around 96.5%.

Hi Cogsy, as far as I understand, purple meths is only dyed that colour to try to stop people drinking it. Meths is a choice of down and out alchoholics, and despite the smell, could be confused for water.

Paul.

 

[Cogsy]

Hi Cogsy, as far as I understand, purple meths is only dyed that colour to try to stop people drinking it. Meths is a choice of down and out alchoholics, and despite the smell, could be confused for water.

Paul.

Next time I run my flamelicker I'll have to do a taste test ...not.

 

[arjc]

I can't help but think that the increased flywheel size is masking the high friction between the moving parts.

Could it be possible that the flywheel is now too heavy, and has too much weight that prevents the engine from keeping its rotation up to speed?

Thanks for all the help!

Alex.