Vibrating engine- story continues

D

Don Cape Cod

Senior Member
Sometime ago I posted problems trying to figure how an engine could vibrate so unbearably. I tore down the engine, had it balanced, 95 grams were noted, put the engine back together, only minor improvement. Well, the only thing left undone was the cam shaft that had been reground. But that just did not compute. Now this engine was a rebuilt with few miles on it, but it had an FS electronic ignition. When you pulled a plug wire, it must have shot a spark an inch & a half long! I had worked on another 5 A's in this group with FS ignitions and they all worked just fine. However, in desperation, I yanked the distributor and stuck in a Henry original. Guess what? The vibration was gone! My fillings & crowns were still in my jaw. This puppy must have been doing some cross talk in the distributor and firing at odd ball times before or after when expected. I just don't know why. I'm just thankfull the problem was resolved!

Now I speak to this because I would like to recommend to you that if you install one of these ignitions, you work out a simple plug to provide a disconnect to the wires entering the distributor. You can then carry a Henry spare, prewired so that you can substitute it for the FS, with a few temporary changes in the coil & switch wiring.

I'll not take up any more room here but you're welcome to contact me for furthur information.
 
"it must have shot a spark an inch & a half long!" WOW! Some guys pay big money for a spark that strong. Way too much for that 'lil ol' model A dizzy, though. I have an FS and get a nice blue 1/2" spark, not enough to jump the contacts inside the distributor.

Like many guys, I always carry a complete, pre-timed-distributor and coil. That's the nice thing about Henry's A (&B). The dizzy has an off-center slot on the bottom, not a gear, so it only goes in one way, permitting you to pre-time a spare. No need to find TDC with the pin on the road if you pre-time your spare.

I also carry a pre-adjusted carb. I thought about getting a tow-bar and hitch to carry a spare Model A, but that would probably be overkill.:rolleyes:
 
Don thanks for posting the results of your investigation. Although I use a stock ignition system myself, your experience might help someone with a similar problem.
 
This A is one of 8 that were stored in a damp, bottom level rental storage place back in 2005 or 6. All had had FS ignitions installed. When I opend up the garage, mold & mildew flooded out! All I had to do was replace the batteries, some fresh gas, and bingo, they all started immediately. Even this one, and it was driven 20 miles to my garage. However, it had a teeth jarring vibration! Now it's been my experience that regular points would have to have been at least cleaned on a couple of these cars before they'd start.

These cars are to be leased/rented and it was necessary to remove the issues of spark and gas valve for the uninitiated. I would have chosen regular points but in B type distributors with centerfugal spark advance.

Even if you carry a spare FS, you have to pull the dash apart, etc to swap out. Not fun along the road in Gray Maine on a wet cold night. Thats why I recommend a good automotive exterior grade plug & socket be used in the distributor cable at the distributor. It would also make possible the use of a preset Henry and a couple of clip leads for the coil if you can't afford two FS's.
 
Mike, back in the good old days, all we needed was a length of rope, an old spare tire fastened to the towing cars bumper, and its front license plate to be used on the A being towed.
 
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