MTFCA Forum

By Bill Stipe on Friday, January 21, 2011 - 09:45 pm:

I used rare earth cylindrical magnets they are under the keepers. Works out great at first I was worried because I thought it put out too much voltage but the coils only use what’s needed to fire them. I have been running 2 summers now and the coils are fine.









By Bill Stipe on Saturday, January 22, 2011 - 09:44 pm:

I did not take any more pictures as I was building it but you set your magnets like the original SS then NN and I selected a magnet long enough so the opposite pole did not interfere with the other about 3/4 long.







By Erich Bruckner, Vancouver, WA on Sunday, January 23, 2011 - 01:21 am:

Bill, does that thing splash enough oil all by itself? Do you have a shot of it all assembled?



By Bill Stipe on Sunday, January 23, 2011 - 10:55 am:

Erich

I thought about that a little too and that is why I drilled the holes as the oil returned from the pan I felt it would get inside the ring then spin out and run back down the back of the motor dropping in the funnel. Also the starter gear throws a lot of oil I made the mistake of starting it with the cover off---not good!!

This motor was an original block with A size crank about .0015 out of round mains and rods I bored the cylinders put new pistons and valves pulled almost all the shims some caps have no shims left and have run it hard for 2 summers. The second summer I had added an outside oiler off the mag post and split intake ports making it a 4 port and added a model A carb. it will run over 60 miles and hour with stock 3.6 gears. I run it in the SD tour and coming home every day when out on the high way we run 50 to 55 to beat the rain. Cindy and I would go for and ice cream run or supper every day the weather would permit all summer long. It still sounds good but I don't want to run the egg shaped crank this next summer so I am trying to find time to take it down and rebuild before the MN tour this summer.













By Bill Stipe on Sunday, January 23, 2011 - 11:09 am:

I do have the crankshaft counter balanced and that I feel does help keep the motor together at higher RPMs but the oiling still has to be there I will most likely cut some fins on the magnet ring when I rebuild now that I know the magnet ring works as well as it did.

Thanks for re-posting that thread, remember reading it and the novel approach for those magnets!

Reminded me of Ford's and Huff's original for patent application....the magnets used weren't the famous horseshoe, but simple flat plates of magnetized iron embedded in the wood disc.

Want.

Do you have a picture of the magnets

Tlitwin wrote: ↑

Tue Feb 05, 2019 8:37 pm

Do you have a picture of the magnets

Bill didn't show any pictures of the magnets used but did say they were about 3/4in long.

Any idea on the diameter?

I’m thinking 1/4” to 3/8”.

Tlitwin wrote: ↑

Wed Feb 06, 2019 6:48 pm

Any idea on the diameter?

He didn't say but I'm thinking 1/2 inch.

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I just finished a similar setup, based on the idea in this post.

I machined a 3/4" x 14 1/4" solid aluminum disk, with holes for attaching where the magnet bases were anchored into the flywheel. Around the perimeter at the 16 magnet positions, I drilled and placed 6 1/4" x 1/4" Samarium Cobalt permanent magnets in the aluminum under each keeper, three on each side, fastened with the keeper and brass screws. I used a heat proof setting compound on each magnet to make sure they stayed put. The magnet poles were placed NN, SS at each position and verified with a compass before using the setting compound.

The magnet size was a mistake. Although the magnet strength is enough at each position, I would have been better off in the long run to purchase the more expensive 3/8" x 3/8" magnets, using just 2 at each position, thus reducing my machine work and giving even more magnetic pull. All of the magnet spools in my engine were bronze and were replaced to insure a decent oil splash. The entire unit was balanced on the flywheel.

I ran into trouble when gapping my coil ring however. It's a freshly rebuilt unit, but no matter what I tried the best clearance I could get was about .028" at the top and .035" on the bottom. The ring and block appear normal, so I finally settled on those clearances.

Edit: A word on those magnet keepers sold by the vendors....before you install them, take a close look at each one. Chances are you'll find they're all bent! The reason? Those keepers are obviously stamped out by a large press and as a result, they all have a slight bend which will give you headaches when trying to gap everything later down the road. I heated mine to cherry red and wholloped each one flat with a hammer. I then draw filed them to a good finish and installed them. I built a mandrel for the flywheel in order to mount it in my 16" lathe, installed the flywheel with the aluminum disk then used a dial indicator to check them. They were STILL off...individually. So, I took a couple of light cuts across the faces and finally got them all down to a uniform height. Not much metal was removed, so their strength was still good.

I don't have my engine finished yet.........close, but not quite there. However, rapid cranking develops about 3 volts A.C., or enough to fire a coil. Once she's done and running I'll do a post with pictures.

George Andreasen wrote: ↑

Fri Feb 15, 2019 10:58 am

I don't have my engine finished yet.........close, but not quite there. However, rapid cranking develops about 3 volts A.C., or enough to fire a coil. Once she's done and running I'll do a post with pictures.

George, I'm looking forward to seeing your work. Thanks for sharing with us.

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Jason Walters

George, your field coil clearances are fine. You need to have about 0.010" additional clearance at the bottom to allow for the vibration of the less-supported (lower) secion of the field coil when the engine is running.

I sure be interested in one