Poppin flame licker timing

[Naiveambition]

Hey everyone. Been going thru the trials of getting my poppin to run and have a few questions I hope can be answered.

When setting the cam it states 15 degrees before tdc. So do you use the centerline of the cam, or is it the leading edge of the cam, meaning at 15' does the valve just start to close.? Look at pic, it's set to just start closing valve now, with counter clockwise rotation.

I'm on the understanding that a vacuum is created at rear tdc that pulls the piston back to next stroke, and flywheel helps make it past front tdc.

So far it sounds like a sick duck, it feels really close like it wants to run, but no luck, even when too hot to touch, so I don't think it a heat problem. Rolls over nicely with almost no resistance. I have honed the cylinder tonite and fixed a leak in cylinder cap. Pulls a nice vacuum against the cylinder, with the pop coming out of cylinder. Am using Coleman fuel. Any help is greatly appreciated

 

[Cogsy]

I've only ever heard of alcohol being used as fuel for flamelickers, not Coleman fuel. Doesn't necessarily mean it can't be used, just I've never come across it, but I'm no expert. Maybe try a different heat source and see if it runs - a carefully applied propane or mapp gas torch works really well.

 

[Naiveambition]

Thanks for the reply.
Have remade a burner using alchohol, or everclear. Moonshine to the rest of us. No luck , also I have read somewhere about Coleman fuel bein used, it does produce a larger flame for same amount of wick area but also produces a higher amount of soot, Seems to almost start, but is missing something.

I'm really close I believe, but also close to giving up. Hoping someone can shed light on the cam position to clear up that possibility, after that may redo piston in graphite. What would be an acceptable clearance for the piston. Cylinder is at .6565 and piston is .6555. There is a small taper at intake end reading .6557

Hoping for answers from others who have built the poppin

 

[Naiveambition]

More tweaking resulted in a couple seconds running under its own power. But dies out soon, any ideas? Happy happy happy.

Still think i need to work on valve sealing

 

[deverett]

The timing instruction for my Scott vacuum engine states:

"Rotate the flywheel until the piston is between 30 and 45 degrees before Bottom Dead Centre. Move the cam until the valve just covers the flame port. The character of the engine can be altered by advancing or retarding the cam. Turning the cam Clockwise makes the engine more docile and vice versa."

These instructions should apply to almost any flame licker.

Dave
The Emerald Isle

 

[allen56am]

I have built (2 Running) poppin engines. I only use 91% Isopropyl Alcohol from Walmart. ($2.50) I have tried many other types of fuel. Nothing I have ever tried works nearly as good. Also everything else makes Soot. Soot is a Very Bad Thing to get in your cylinder and on your piston. I have also have good luck with Propane also. But I just don't like the big bulky tank, Hose and burner. I am thinking if you switch to 91% Isopropyl alcohol and keep moving you cam timing a little bit at a time you will have a running engine very soon. By the way. The 15 degree cam timing is just a good place to start. Put it at 15 the start advancing and retarding until you find a place it is happy to run for you. I have found that just about every engine is different. What ever you Don't Give Up ! But if you do. Please sell me your engine Really Cheap ! Lol.lol.lol.

 

[Jamie Barton]

I got my old poppin to run nicely on nitro rc fuel because it was all I had to test it with at the time, I then ran it on some cheap purple lamp oil which looked a lot like methylated spirit. Timing was done by trial and error until a sweet spot was found. I had a problem at first with the valve which was made from a feeler gauge. The first one was too thin and when hot it would curl. The spring for pulling the valve back down also made a big difference. If its smooth, has good suction and a good valve seal it will run

 

[BillC]

Ambition, These engines are so 'low power' that they must have very, very little friction anywhere; absolutely no piston drag for example. The Poppin that I built years ago did OK at first but the more it was run - with an addition in the bore of some Marvel Mystery Oil- the better it ran. Use alcohol in a wick feed burner. The exposed wick becomes the speed control...
BillC

 

[nel2lar]

Naiveambition
The way I find TDC is put something in the valve slot and turn the piston until it hits the inserted material, mark the flywheel with a reference then turn the opposite way and to stop and mark the the flywheel again. With a divider find the center spot on the flywheel, that will be your TDC.
Good luck with your poppin
Nelson

 

[Naiveambition]

My apologies gentlemen , I had no idea I left this thread open, as it's been a good while since building my flamelickers. I believe the one here is the first I built , then built another later on. I combined the build threads for anyone interested . Both ended up with my fathers, after I played with em a little of course and still run today.
If I remember correctly, I put the piston at tdc and used a angle finder on the crank( with the rotation I think )for the degrees needed then tightened the con rod. Then worked in small increments to tweak. I do remember paying attention to the blow force on the flame. When correct most of the time the flame is being sucked in nice and clean , vs a erratic moving flame. This is a good indicator of the closing time for the valve. The closer you get to a "standup and suck in only "flame the better. any blowing on the flame will be visible.
Thanks for taking time to post to the thread, as it may be beneficial to others also.

 

[olympic]

I built one of these paperweights a couple of years ago. Perhaps the information in this conversation will help me turn it into something useful....

 

[nel2lar]

Naiveambition
In my opinion there is nothing more amazing than a flame licker sittng running smooth as silk. Nothing but the flame in perfect time with the cylinder opening. You have done a superb job on your builds.
Thanks for sharing.
Nelson