Vacuum advance or not ?

Wow, what a concept! You are using the gear as your jig, if I read this right.
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Yes, that's correct. The gear material is quite hard so it serves well as a jig at least once.

The shavings on the bit are there to fool me, right?
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No. I took that picture right after I finished drilling the shaft.

You don't re-drill the holes in the gear or do you?
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No.

1/8" spring pin?
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I think it's 1/8", a roll pin.

So, from Ol'Ron I learn you used to work on airplanes and I used to fly 'em.
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No, I didn't "work on them," I redesigned and built experimental airplanes for fun. And what great fun it was!
 
36tbird said:
Richard, very cool jig. Darn, something else I will probably try to copy.
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I have a ton of pictures of that rig, plus a little video I made showing Ol' Ron how to use the one I made for him.

If you get serious about building one, these resources could save you a bunch of time.
 
I guess I was wrong about the speed. We discussed the building of a miniature B-17 two seater powered by 4 flatheads with L-100 cams. I can just picture the fly by at Oskosh. too soon old.
 
Richard in Florida said:
The guy who bought it ran it out of fuel the next day and totally it in some farmer's field. He walked away unhurt, but the little airplane was completely destroyed. Six and half years of work down the tubes.
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Out of curiosity, did it have a fuel gauge? My old J-3 had the basic cork and rod thru the gas cap.
 
I've seen a few go that way ending up belly up in a field and some were the kit helicopters too. I was around enough Volkswagen aircooled motors to gain an appreciation for the little Lycomings & Contenintals. They aren't bullet proof but at least they have a purpose built crankshaft for turning a prop. Rotorway modified the VW engine so much you can't even recognize it. It's more like an early Subaru (Nakajima).

I also remember the Pietenpol kits that had the Model T engine. It's hard to figure that heavy cast iron engine could do the job but they actually flew.
 
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Richard in Florida said:
Yes, it had a calibrated, working fuel gauge. On top of that, I'd briefed him about gallons vs duration. There was no excuse.

The NTSB guy who called me said the tank was bone dry.
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Yep! no excuse. Never had to calibrate the one on my J-3, just watch it dance around and get shorter:)
 
I realize this has little to do with the discussion re vacuum advance, but
thought I would add the way I did the advance deal on my 59 type engine.
As everyone knows, you really need to know TDC before you can do any accurate
setup. Best is probably the piston stop method.
I'm using a 37-41 Helmet distributor with the early (37-40) advance setup. These items are numbered 68, rather than the commonly used 11-A. And the distributor is converted with a Pertronix Ignitor.
The pictures are hard to see, because I can't get the camera in there close enough, but hopefully you get the idea.
I took the model 59 front crank pulley and turned off the front pulley, leaving just the rear, much like the 39 Std pulley. It measures approx 5 1/4" in diameter. I then got a piece of 5" tubing and had a ring turned to 1/2". I then welded this to the inside of the existing pulley (it just fits perfectly inside the lip of the pulley, and it clears the oil pan nicely). I then bought some timing tape from Speedway or Summit that fits a Pontiac V8 and is for a 5 1/4" pulley. (I know it's not perfect for the 5" tube, but it's close enough).
I then made a pointer that mounts to one of the distributor bolts.
When assembled, it shows TDC and degrees out to 40 BTDC.
With the distributor internals I'm using, I have the initial advance set to 12 degrees, and the total set to 28 max. No pinging at all.
The engine is 290 cubes, with one of Pete's Potvin 425 (Eliminator) cams. The engine is very strong.

The first pic shows the timing indicator, if you can see it? The next shows the ring with timing tape (it really does have nice numbers on it)
Now, if I could just add an vacuum advance to this distributor, I'd really be set
 

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Charlie, the adjustable canisters on the market will be marked B33 on the bracket behind the vacuum can. Moroso used to market one, but now they only sell the HEI version which has a longer bracket. Crane Cams, Accel, and probably some others will have the correct one for the points type distributor. Check Jegs or Summit on-line catalogs.
 
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