Thanks to a couple of friends, we have the mag working on our "K". For the first time I'm able to start on magneto. However, there is a slight "woof" when runnning at speed. If the car did it on coils (two separate ignition systems, high tension Bosch DU6 and timer/coils) I'd suspect a sticky valve (sounds like a sticky intake valve). However, it runs fine on coils, so I know it's one cylinder on mag.
What do you think of this spark plug. All the plugs look like this. I'm setting the gap at .22 (I've found Bosch info sayng .19, while the Ford Model K says to set the plugs at 1/32 to 1/64th inch).
Thanks for your suggestions and opinions,
BTW, getting ready for the Early Ford Tour and New London to New Brighton Tour so I'm trying to get everything "up to snuff".
Use some sealer around the spark plugs. The Wuff describes a compression leak around the threads between the head and the plug.
Wouldn't it "woof" when running on coils too?
I thought it might be a slow/partially firing plug (or mag contact, or short at moderate to high speed. It also seems more evident when not pulling, just running at speed.
Lean it down 1/4 turn. The electrode and last 1/32" of the ground looks fine (tan is ideal). Finding a hotter (good luck) plug may help too. The 1/32" gap is .031" and 1/64" about .016 by feeler gage. Try opening the gap some? BWDIK? ws
I'm not overly excited about the carb I'm running, it seems to need to be too rich for acceleration. Also, the outer cylinders seem to be more carboned up than the inside. However, I thought the inner cylinders would be richer than the outer, due to the distance the mixture must travel (but I'm just guessing on that).
Thanks again guys,
Are the sparkplugs fired by the mag farther from the intake valve than the others? The farther from the intake valve, the leaner the mixture, and harder to fire.
Are you sure the intake isn't leaking? I have no idea of the K setup, but the 6cyl opposed Franklin has you mount the jugs loose on the crankcase, then tighten the intake and exhaust manifolds without gaskets, allowing the jugs to turn to fit. Then the jugs are secured.
Is there an easy way to mount coolant or cylinder head temperature senders? The engine may be running too cool.
There is a local 1910 Locomobile that was overheating, in spite of rebuilt waterpump. Turns out the pump was too strong, pumping faster than the radiator could supply, and cavitating, which means no flow at all.
You're running rich Rob. I had the same set of plugs in my first T before I had any concept of setting the carb needle correctly. How'd you get them? LOL.
Ralph and Charlie,
The mag plugs are over the exhaust valve, the coil plugs over the intake.
My next plan (B) is to change the plug wires one at a time to try to isolate the cylinder that is skipping. If I lean the mixture any more the car won't idle right.
Again, I'm not too happy with the carburetor either. Stan Howe is joining us at New London and we'll probably try the original Buffalo carb then. Meanwhile, I'll try to figure out which cylinder is the problem.
I suppose it wouldn't be easy to change the plug wires so the mag feeds the plugs over the intake valves. That would further isolate it. Have you tried running richer on mag than on coils? Especially at less than full throttle, not all the exhaust gas is gone, and when the fresh charge comes in, it does not get as rich near the exhaust valve. It's hot and dry there.
I knew the Lizard Head was doomed when I saw he had put the plugs too far away from the intake valve.
Do you not have the option of both plugs firing at once? That's how it's done in aircraft engines. You get more power that way.
Looks like too cold spark plug heat range. I am surprised a Model K would have something with such a heavy electrode and ground. Is that some sort of modern plug Rob? Can't you use a Champion X plug?
The problem seems to be solved (although I tried so many things I'm not sure what "cured" it )
I replaced one plug. These are old Champion brass tops. One looked pretty bad so I replaced it with a Champion X.
Royce, all Ford's, A,B,C,F,K,NR and S use the same plug as the T (size). I guess we should say Model Ts use a Model A plug.
After cleaning all the plugs, it ran fine at all speeds on magneto only. And yes, the car can be run on both mag and battery/timer/coils (12 plugs, dual ignition). However, the manual says to turn off the battery after starting to conserve it. While I'm not so concerned about battery usage, the K is incredibly quiet with the coils off. With coils on, it is a noisy affair (imagine your T coils, only one and half times as many "chirping" on each revolution).
Anyway, Ford advertising said a K should be able to shift into high gear at 4 to 6 miles an hour. In some hill climb contests, part of the contest was to see how slow a car could take a hill on high gear, so my goal was to get to a point where on level pavement, I could start in high gear (no low), on magneto, and with very little clutch slippage go. Today, it happened for the first time. Needless to say, I'm a happy camper, and impressed with the capability of this engine when everything is working properly.
I still am not sure the Schebler carb is the right fit, but Stan Howe will be at New London to New Brighton, and we'll try his newly rebuilt Buffalo carb (the original one for a K) on it and see what happens.
Meanwhile, thank all of you for your great ideas and help. Also, Ralph, it seems when on mag that richening up the mixture a bit helps, so that idea may be the ticket. Also, maybe I should switch the mag plugs to the intake, if I intend to run primarily on mag. What do you think?
OK, run on mag only for ghetto cruising, but when you want max power, select BOTH.
If you can use the mag for the plugs closest to the intake valve for most running, Rob, it will be ideal. You can then run a leaner mix and save gas. Is there any chance that was the original layout?
BTW, I think you should label your threads: Pre-T.
I'm not sure what the original placement was. Because the K has such a long distance between carb and intake, maybe the plugs over the intake were the battery/coil plugs (to help with starting)?
I might be able to find an original photo and determine how they were wired.
Yes, Pre T might be good. I just use OT when in doubt. Thanks for your suggestions,
In an engine that's already running at less than WOT, the air farthest from the intake is not only extra lean, but is lacking in oxygen, as not all the exhaust gas is expelled.
Before first start, the cyl should be full of fresh air, and choking brings in all the fuel needed, so being far from the intake valve is not as much a penalty.
A couple of period pics, one from the operators manual. Unfortunately plug wiring isn't shown.
This second photo shows an early 1906 engine. The exhaust manifold was below the intake. This was probably ok to preheat the mixture, but cooked the magneto. By the 1907 model (first pic) the intake and exhaust placement were changed.