Author Topic: Building the I F Allman from Alyn Foundry  (Read 2121 times)

Offline Alyn Foundry

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Re: Building the I F Allman from Alyn Foundry
« Reply #15 on: February 15, 2020, 01:52:22 PM »
Hi Jason.

I would let it stay, but it's your thread. The IF Allman that you're building is the father of the engine that DeBolt marketed.

I still think Vincent made a nicer version, but I'm biased lol....

Cheers Graham.
« Last Edit: February 15, 2020, 01:58:58 PM by Alyn Foundry »

Offline Jasonb

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Re: Building the I F Allman from Alyn Foundry
« Reply #16 on: July 01, 2020, 07:53:55 PM »
With another IF Allman up and running on a temporary burner I thought it best to show mine here so other builders can join in.

Starting with the valve that controls the gas that the engine uses to run, the flow of which is controlled by the governor on the patent but I did not find it very effective on mine



After fettling the cast brass body was machined with a combination of lathe and mill, here I opted to machine the round flanges to hexagons





A short length of pipe connects the gas valve to the inlet valve block, the top plug and valve spindle are plain turning jobs



The burner was made from three pieces of brass silver soldered together, the main body was drilled to fit over the hot tube and a recess for the top plate bored in the lathe followed by milling a horse shoe shaped recess for the gas passage, the metal between the ends of the horse shoe was cross drilled and tapped for a grub screw so the burner could be clamped to the hot tube at the desired height. the top plate was just a turned brass "washer" and then a threaded union for the gas piping goes into a hole on the opposite side.



After silver soldering together I mounted my small Unimat 3 indexing head at an angle of 15degrees and drilled the ring of holes so that the flames were directed towards the hot tube.



With the burner mounted two commercial 1/8" BSP elbows were used to dogleg the route down and away from the line of the gas valve.



I wanted to use the Sievert burners jet to get the right gas flow to the burner so the end of one was unscrewed and a piece of brass bored and threaded to make an adaptor, here you can see the Sievert burner being used to check the screwcut thread.






Offline Jasonb

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Re: Building the I F Allman from Alyn Foundry
« Reply #17 on: July 01, 2020, 08:07:31 PM »
A quick test with gas showed the ring got the hot tube nice and hot though the heat does move down once the chimney is in place





To control the flow of gas to engine and burner I made up a twin valve consisting of a vertical body with two rods soldered through it at right angles plus union for the incomming steam. The body was drilled out and the two spindle bodies drilled, taper reamed and tapped for the spindles as well as threaded for gland nuts.



Stainless spindles were turned together with a "d" bit to cut the tapered seats



It was then just a case of some short bits of copper pipe and union nuts to plumb everything up.





I also had to make a banjo fitting to get a neat pipe connection into the gas valve






Online Chipmaster

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Re: Building the I F Allman from Alyn Foundry
« Reply #18 on: July 01, 2020, 09:21:42 PM »
The other Allman running on a temporary burner,


and a Slo Mo video of it. Reckon I messed up editing and duplicated the slo Mo section the engine really speeds up in the last ten seconds of the video.
 

What size are the holes in the top of your burner Jason?

Andy

Offline Jasonb

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Re: Building the I F Allman from Alyn Foundry
« Reply #19 on: July 02, 2020, 08:12:36 AM »
1.0mm holes