Hi all - update on the engine:
I had to come home early from work yesterday afternoon so I took the opportunity to go and buy some Industrial Denatured Alcohol (Industrial Meths, which is 99% ethanol). Luckily there is an oil / paint / chemical merchant near by called Smith & Allan. Cost me £16.02 for 5 litres.
Tried the engine last night with the new fuel and with the wick in the strange position that I found best before. With the tiniest touch of the flywheel it burst into life straight from lighting the burner! I was gobsmacked, it was running away with itself, never seen it going so fast, but then it stopped. Partly because the flame was twitching around so much at that speed and partly because some condensation built up.
I restarted it, here is the video - it didn't go for long but probably longer than it had done, still going at a fair rate! This was with the oil that was left from the previous run a couple of days before, but I'd run out of that electric razor oil now:

After this it was a bit of a pain and I was fiddling around for quite a bit to get it started again, probably took a while to warm up. But then i decided to try some engine oil as suggested by David D and Mike R C on HMEM. I only had 10w40 semi synthetic which is a bit thicker than the 5w30 suggested. Anyway, I tried some of that as well as messing around with flame positions again. I also put a drop of oil down each side of the flywheel and on the push rod etc.
Bizzarely I then found a bit of a sweet spot for the burner that seems to make it run not as fast, but more consistently - funnily enough, this was where Jan Ridders suggests and Jeroen Jonkman and Bogs have theirs on the other side of the port.
This is the longest video I captured as before whenever I reached for the camera it stopped! It had fun for a couple of minutes before I started this video and it only stopped because it ran out of fuel this time! You will notice the different flame position and you might notice that it is running in the opposite direction. It seems to run the same in either direction, it’s just that this one tends to try to tighten the crankpin rather than loosen it.


I then filled the burner back up and tried again, it ran until the burner ran out, which was probably over 20 mins only stopping a couple of times on the way due to the flame fluttering a bit too much. I think a larger wick would give a more stable and wider flame which would help a bit. What also happens is the engine speeds up, then the flame gets blown around a bit and it slows down, flame stabilises and it picks back up again. Anyway, it did a stint of over 15 minutes continuously.
I tried to run it again today but because the oil had thickened up with reduced temperature it took a few minutes to warm up but then settled into that steady rhythm again.

I’m absolutely chuffed with this project now and I consider it complete. I was going to open some Cava we have in the fridge to celebrate but the wife wouldn’t let me

Only problem now is, what to do with all that metal I bought for ‘Poppin’. I might try to design a Hit & Miss IC engine based on the design of poppin.
Nick