building a new flame sucker

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madjackghengis:
Hi all, didn't get much done yesterday, too much fiddling with fuel injection in a VW, and messing with dragging brake pads on another friend's front end. I did get a cam blank machined though, and today I should be able to get some actual angles on it, and see about opening and closing that valve on time, and then fixing the engine to a nice piece of old oak or walnut. I wouldn't mind actually getting it to run today, but that's a "what if", and not a goal, just chance. I've got an idea regarding flames, resonant chambers and the possibility of making such things work to improve the amount of heat actually taken in by such engines, so I deliberately made the port huge. We shall see how it all shakes out. More pictures will be posted, didn't take enough yesterday to remember to bring home the camera. When you run across a piece of aluminum bronze, cherish it like gold, nothing machines quite like it, and no other bronze is quite as strong and hard, so it is very nice to have, that's what the chunk of unknown bronze I made the cam blank turned out to be, much better than the brass I thought I was falling back on, if you know what I mean. Ta ta for now, :poke: mad jack

madjackghengis:
Hi all, yesterday was interesting, I got the cam machined, I think it's pretty close to right, but not certain yet, and spent the evening playing with the engine while trying to get the cam to just the right place to do what it needs to do.

turning the hub o.d. to the minimal size of the cam actuating lobe

I turned to calculated o.d. for the lobe, and now I'm cutting off the cam trying to save the bit of shaft that is left

I put the cam blank in the milling vise, milled off a straight edge down to the hub

using the swag method, I rotated the cam blank to what looks to be a good angle, and milled again, down to the hub, leaving a couple thousandths for final filing fit

with swarf out of the way, using a wiggler to center the hub for a set screw, or grub screw if you prefer

hub centered

hub centered, center drilled and tap drilled, tapping it for #4-40 set screw

one set screw is an invitation for vibration loosening, so the cam is turned to put another set screw in, now needing centering again, with the wiggler

Centered, drilling with a center drill

drilling tapping size, after center drilling, for the second set screw, then tapping as per the first one

After tapping the second set screw hole, I milled off the sharp point where the two milled flats forming the angle of the cam meet up, to minimize filing

moving the cam by eye, then milling off the sharp corner which will be filed to a radius for the actuating arm to follow

milling off the other corner

the corner, after milling it down thirty five thousandths

while on the mill, centering up the flywheel for its second set screw

the other edge of the flywheel touched off with the wiggler

hub centered, note the extra long center drill to reach the hub past the flywheel

center drilled and drilled, the tap barely clears the top of the wheel, extreme care keeping the tap in proper alignment

when the tap wrench no longer reaches, my four inch crescent wrench comes in handy to complete the tapping operation, never leave home without it, but don't take it to airports

back to the cam, with the rough cam in the vise on the bench, the center is carefully filed down with my finest files, to the hub, matching the radius, and putting a radius of "good proportion" on the corner

another view of the cam in the bench vise

the cam, ready for initial installation

and the cam, finally installed on the mainshaft, now comes the hard part, timing with no specs. I've spent the rest of the evening moving it around, while comparing valve and piston movement with that of my Duclos flame sucker, having milled the cam a bit more before closing down the shop, because the valve was open too long, I seem to have the timing pretty close, and having gone through my box of miscellaneous springs, I think I will have to wind one, as so far, none seems to fit either being too strong, or too weak. I think I will try a coiled tangential spring, around the pivot of the lever, with an arm against the lever, and the other arm against some adjusting arm of some sort, so I can vary the pressure on the valve. I've got some music wire which I think will be about right in size to give good tension, and Herr Bettinger uses such to act as a throttle on some of his flamenfergessen's (flame eaters). I hope today to have a solid base, a burner with enough flame, and maybe a running engine, touch wood as Nick would say. I think I have a piece of oak begging to be a part of this piece of work and I like oak. Ta ta for now, mad jack

NickG:
Great work on the cam Jack, I think the poppin one is a similar shape. Can't wait - I'll be listening out for it in my sleep then checking again tomorrow at work!

Nick

sbwhart:
Great work Jack looking real well.

Are you going to convert that grenade into the burner :headbang: :nrocks:

Stew

arnoldb:
Looking good Jack :thumbup: - you're near to firing it up now :D

:beer:, Arnold

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