Not having any spare vaporisers for an X246B, I had to resort to making one. * Firstly, to get away from the unique thread on the Tilley vaporiser, an old control cock was drilled and tapped 10 x 1 m/m. Then a brass adaptor was made, threaded to fit the cock and drilled to take a 3/8" tube. Both shown here - The small pad which pushes the Tilley pricker wire up was drilled and tapped 2 x 0.4 m/m. This enables a made-up pricker rod to be installed, and ensures a return downstroke thus avoiding the use of a return spring on the pricker rod. The 2 m/m hole is just visible above. A length of aircraft tubing was drilled and tapped at one end 8 x 1 m/m, and a steel insert made up to fit (from 3/8 hex), then drilled and tapped to take an Austramax nipple, 3/16 x 32 (10-32) UNF. All of which gave worries about - the thicker walls of the tube, thicker than the Tilley vaporiser, and the mass of metal at the top. I could have used a thinwall aircraft tubing, but as I originally intended to gas weld the top insert to the tube I thought that the thinner tubing would be too difficult to weld. Fortunately the insert is a gas-tight fit, so no weld or braze is necessary. For the brass adaptor I had no hex bar, so had to use round bar, and put 3 blind holes to tighten it. And making a rod for my own back, I then had to make a pin spanner for it, using a 4 inch length of 10 x 3 flat steel strip curved round a bar, like a hockey stick, drilled & tapped to take a 3 m/m screw. Crude but effective, it was too shy to appear here. The adaptor was silver brazed to the tube. I fear that the flamelets are smaller than those from a Tilley vaporiser, which may suggest that the Austramax nipple has a smaller jet, I dunno. I'm reluctant to drill it out, to enlarge it, but to what size ? It has burned for 20 - 30 minutes until shutdown, so the thicker tubing works o.k. Here is the flame from a Tilley vaporiser, slightly bigger - I have yet to put a mantle on; expect to see only 80 - 90 % light. The hardest part will be making a pricker, getting the six thou wire into the 1 m/m tube, and straight; a job I put off as long as possible. Next time I might extract the base from an old Tilley vaporiser and build on that. And simplify the top end. My main concerns were - getting enough heat into the vaporiser, too much steel at the top where the heat is needed, and no internal guides, guide plates, baffles, mesh, or coils to guide and align the pricker rod. Then next one should be easier, and more simple. Cheers.
Thanks fellas. I expect to complete this project later this month. The control cock I used turned out to be well worn, with lost motion in the mechanism meaning less vertical rise of the pricker rod. I will measure a few, just to see what the travel distance is. We know that the Tilley pricker wire is very short, since the metal is so thin at the top of the Tilley vaporiser, a long wire is not necessary. So I hope there will be enough travel of the new pricker rod to clear the new nipple, without impeding the vapor flow. Finally I must apologize for having put up so many photos. I could not get the pdf's to migrate over to the message post, so had to take them from the email inbox. Hopefully, workshop skills are inversely proportionate to computer skills, at least in my case. Cheers.
It has run for over 4 hours on about 200 ml or less of kerosene. No pricker yet - that's the hardest part. Using a cheap mantle for tryout. I'm surprised at the success of this experiment, as I was expecting much difficulty in getting enough heat through the heavy walled tubing of the vaporiser. It's really a tribute to Tilley's clever design of having the mantle around the vaporiser, not just beside it.
@podbros Yes, thanks. Pleased with the result, after all that head scratching to make those adaptors. I've learned a few lessons, the next one will be easier. Cheers.
Excellent work! As long as the tank is clean and you filter the fuel through a fine mesh, problems with jet blockage ought to be few. Couldn't you just cut down and re-weld an old pricker wire - maybe the longer 169?
@David Shouksmith Thank you. Yes, all fuel is filtered through a fine mesh, and it's surprising to see the very small particles of dust trapped on top of the mesh, even from a new bottle of Kerosene. The Tilley pricker wire is only about 0.035", 35 thou, less than 1 m/m diameter so not easy to weld. It's a fair question, and gives me a couple of ideas on making prickers. Cheers.
