Flame Gulper not working.

[PeterB]

Maybe this thread can help you?
http://www.homemodelenginemachinist.com/showthread.php?t=19942

 

[Omnimill]

If it helps, others have suggested that French Polish thinners is industrial meths, likely to be around 98% proof.
I have some and it does burn cleanly but I have no idea of the actual strength of it.

 

[Cogsy]

Did a little research just for my own curiosity, maximum alcohol percentage of normal 'pure' ethanol (not the special anhydrous stuff) is 96.48%. You can achieve a higher concentration (somehow) but it will simply absorb moisture from air to get back to the 96.48% stable maximum.

On the other hand, the standard strength of 'meths' varies from country to country, so my research was almost a waste of time, though I did amuse myself.

 

[arjc]

The strength of what i'm using is 97-98%. we use it at work in chemical stratification and reductions. whether or not you can get it retail, i don't know.

Still struggling to get it to run however, made new pistons (again) and re-bored my cylinder, to make sure it was 100% concentric. now has a fitting tolerance of just under 0.02.

Is it likely that the engine will just burst into life randomly dependent on flame position?

 

[Cogsy]

I would say yes, it is. That's what happened to mine. It seemed to want to go, I fiddled around, tried again, etc, for a week, then it ran. I moved the flame slightly and it stopped. If everything else is right, it must be the flame.

 

[arjc]

completely forgot to ask, is it possible my wick is sufficient enough? I'm only using string coiled around itself. do purpose wicks give better flame?

 

[Omnimill]

I would say yes, it is. That's what happened to mine. It seemed to want to go, I fiddled around, tried again, etc, for a week, then it ran. I moved the flame slightly and it stopped. If everything else is right, it must be the flame.

Mine was similar.

Best wick to get is the fibre glass ones if you can get it. I got some 6mm dia from eBay but camping/hardware shops may sell it if you have a local one?

 

[arjc]

Waiting for wicks from ebay.

haven't really had chance to play with it over the weekend, left it at work.

Hopefully will see some progress this week. cheers for all the help.

 

[arjc]

Update! changed my bearings today due to one that had become grindy for some reason.
Main problem is, now the crank doesn't abide by the 1.5 - 2 minutes suggested by Jan in his checklist. However, it still runs for over 20 seconds with the piston attached, and over 8 with the valve and piston attached.

Do you think this will suffice?

 

[Cogsy]

Sounds like it should be fine, I'm pretty sure mine never made over 1 minute with just the flywheel. Good luck.

 

[arjc]

another question. it seems as though the valve continues to move due to the vacuum caused by the gas after the piston has reached TDC. should it do this?

 

[Omnimill]

I don't think mine free wheeled for more than a minute.

 

[Cogsy]

another question. it seems as though the valve continues to move due to the vacuum caused by the gas after the piston has reached TDC. should it do this?

Not sure what you mean here. There shouldn't be any vacuum at TDC (top dead centre) as the valve should be open until BDC (bottom dead centre) where it should close.

Mine is set up so the valve can only move to just shut and is stopped from moving any further down the bore (If it can move further then vacuum power is being wasted moving the valvle down instead of the piston up, then more power is wasted moving the valve out of the way more than it needs to). Also, at TDC the valve is set to just move enough to open the port (again, if it's allowed to move too far, precious power is wasted moving it back again).

Ideally, I would think the minimum amount of movement in the valve position, while still allowing it to do it's job, would be the best. You do need to make sure it doesn't bind the piston at all though. These engines don't make much power, so you've got to use it wisely.

 

[arjc]

Got it running guys!!!!

Although, the longest I've had it run is around 2 minutes, and it runs at mega slow revs. Haha. Kinda like the low revs though.

http://youtu.be/yNL6I5DqM5U

Thanks for the help. just need a higher purity fuel, as this fuel gums up the valve after a while.

 

[Omnimill]

Well done! Mine doesn't run very fast either.

 

[Cogsy]

I missed your post - Congrats on getting it to run, I knew you'd get it! Mine mostly runs about that speed as well, sometimes a little faster.

Mine also only runs around 2 minutes then gets too hot. I think it's because of the aluminium cylinder. Next flamelicker will have a cast iron cylinder (should be stainless but I'm too chicken to machine it) and a graphite piston so it should run much longer.

I'm about to start a very long project and I'm going to need smaller 'side' projects to break it up a bit. You've inspired me to make the first of those 'side' projects a flamelicker, probably a Poppin - I've heard good things about them. They also run fast and impress non-machining friends.

 

[deverett]

Snip
Mine also only runs around 2 minutes then gets too hot. I think it's because of the aluminium cylinder. Next flamelicker will have a cast iron cylinder (should be stainless but I'm too chicken to machine it) and a graphite piston so it should run much longer.

303 grade of stainless steel machines quite easily, nothing to be afraid of there. Depends on what is more easily (cheaply) available?

Dave
The Emerald Isle

 

[Omnimill]

Jan Ridders updated one of his designs to include a graphite piston and Stainless cylinder. He chose not to cut conventional fins on the cylinder which is probably a good idea as I think it may be a bit challenging on some small Lathes. I'd actually like to try a stainless sleeve in an aluminium cylinder but haven't seen any suitable stainless tube yet.

 

[Petit]

Nice work! I think mine will run for about 4 minutes, untill it gets super hot then i think all the clearances go out n you loose vacuum seal. I have a stainless cylinder n coarse grade graphite piston. Not sure how fast mine runs but it has a tendency to go so quick that it kinda runs away with itself, ull be able to see what i mean in the second vid on my thread about it. I think the best i got out of my flywheel was 1min 15seconds if i remember rightly. I found that if i slackend of the bearing posts abit i cud get a few more seconds out of it. The less resistance you have the better it will run. I also found the height n thickness of the wick made a difference, it needs to be a strong flame so the exhaust pressure doesnt blow the flame about as easily as a small flame. I think i used 8mm fibreglass wick and i run it on isopropyl, seemed to work best for me!