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OT Question about Model N, R, S

Posted: Sun Oct 06, 2019 12:10 pm
by WayneJ
I enjoyed viewing the pictures of the Ford Model N / R that was recently sold in the classified section of the forum. I noticed the engine had two spark plugs per cylinder. Not being familiar with these cars, can someone explain to me how that works? Thank you.
ford N2.JPG.jpg
ford N2.JPG.jpg (61.34 KiB) Viewed 324 times

Re: OT Question about Model N, R, S

Posted: Sun Oct 06, 2019 12:52 pm
by Rich Eagle
One set is fired by the external magneto mounted to the left and one set is fired by the coils as was standard. The extra set of plugs are simply in threaded plugs in the valve access holes which normally don't have the threaded hole. It looks like ample room for the Bosch magneto to be installed. Whether both systems are used at the same time or used singly depends on how they are set up. Nice photo. I hadn't seen it.
Rich

Re: OT Question about Model N, R, S

Posted: Sun Oct 06, 2019 1:08 pm
by WayneJ
So are you saying that Models N, R, & S left the factory with only one spark plug per cylinder?

Re: OT Question about Model N, R, S

Posted: Sun Oct 06, 2019 1:15 pm
by Rich Eagle
Yes, as far as I know. A box of coils fired by battery.

Re: OT Question about Model N, R, S

Posted: Sun Oct 06, 2019 1:25 pm
by WayneJ
Thank you for the explanation.

Re: OT Question about Model N, R, S

Posted: Sun Oct 06, 2019 2:30 pm
by Dropacent
The two holes in the head casting were used to machine the the valve seats. When it left ford, each head had a closed plug in one and a spark plug plug in the other. Through time, many owners added a priming petcock in the solid plug. That makes a nice look now, lotsa brass. You don’t see this pictured example much, but it would allow a battery ignition from the factory, and a separate magneto ignition. The dry cel battery ignition was a pain, ( it took 8, 4 to use and 4 to switch to when the first set died.) and some of the very earliest accessory ads i’ve seen is for accessory magneto ignitions for the NRS cars. Quite a few different types and brands were offered.