Bench starting a '36 Flathead..have ???'s

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deadelvis2000

Senior Member
Hi Fordbarn!

I was given this babbited 1936 flathead motor. It supposedly is a runner. It does turn over and has compression. This weekend I would like to start her up and see if indeed it will run. I have taken all the precautions of pre-lubeing the cylinders, priming the oil pump, fresh gas, etc.

Here is my question. I am not familiar with the diving bell distributor at all. In fact, I cant even tell where to run a wire to it. Can anyone guide me in the right direction? Any other advice on the electrical aspect of "bench starting" this motor?

I am pretty excited.....
 

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If you look on the top of the round coil there is a little terminal sticking up,just next to the vacuum connection, thats the were the wire from the ignition switch via the resistor goes,you can run 6 volts on it BUT only for a short time as the coil will heat up,you should fit a temporary resistor in the feed to it so it gets the 3 volts.
Lawrie
 
OK...I fired up the motor this weekend and she runs great. I am confused about the 3 volts that Lawrie was talking about to the coil. I just ran the thing off of the 6 volt battery keeping a hand on the top of the diving bell coil and it stayed cool to the touch. Can anyone explain the reason to downsize the voltage to the coil/????
 
well eventually the points will burn up faster and the coil will short out or loose power as it runs, yea I know some will question the points thing but it happens!!
 
Thanks Alan. OK I understand the logic...... so how can I acheive the downsize in voltage? Is there a balist resistor that came in the 36 cars that took care of that? Can I obtain one at say...Macs?
 
deadelvis2000 said:
Thanks Alan. OK I understand the logic...... so how can I acheive the downsize in voltage? Is there a balist resistor that came in the 36 cars that took care of that? Can I obtain one at say...Macs?
Click to expand...


the ford cars and trucks had a resister for the coil, 36s has it under the dash
 
congratulations on getting it started and another flathead living....lol....link is to MacVP's website showing the wiring diagram.....#12250 is the fuse block and can be bought at the catlog places like Mac's...i think that is what you need, but not sure where the resistor is, as shown in second link....it's between the ignition switch and the distributor....hopefully someone will give you the value of that resistor and you could wire one into you wiring....good luck....Mike

http://www.vanpeltsales.com/FH_web/...cs/Flathead_Electrical_wirediagram1936car.jpg

http://www.vanpeltsales.com/FH_web/...cs/Flathead_Electrical_wirediagram1936car.jpg
 
The resistor is 0.4ohms. Unless you are going for a points car, I recommend a new solid state power resistor with heat sink. For a third of the price with out all the problems of the old wire ones they are a bargain. Solved all my problems of hot no start etc.
 
Joe KCMO said:
The resistor is 0.4ohms. Unless you are going for a points car, I recommend a new solid state power resistor with heat sink. For a third of the price with out all the problems of the old wire ones they are a bargain. Solved all my problems of hot no start etc.
Click to expand...

Could you say exactly what it is that you bought? And where from?

Thanks.

Mart.
 
From an electronic supply seller buy a 50 Watt wire wound power resistor. They are available at various ohms from 0.1 and up. I bought several and experimented for the one which worked best for me. The stock resistor gave me 2.8 volts at the coil. I use 0.35ohms (0.2+0.15ohm) which gives me about 3.5 volts. The engine runs as it should. The new resistor is also enclosed in an aluminum heat sink. The old resistor varied and increased in resistance as it heated up(why my engine would not start when hot). I use Newark electronics out of new jersey usa. About $5. My opinion is the old style resistor are pretty close to being marginally good. Cause as many problems as they solve.
 

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For a 'temporary' resistor, I usually just use one from my junk pile. I have a variety of 55-74 chevy and Jeep ignition resistors for this purpose. If you happen to be a sbf or mopar fan, you would have resistors from them that would work, also. If I'm doing this sort of 'test-start-up' on 12V, I just put in two, or three, of the chevy or Jeep resistors in series. Works fine for a short run. As posted above, if you have to buy one, just go to napa and get the replacement one for 32-48, or, if you don't have a napa, any parts store will be able to get a Standard Motor, or Echlin equivalent. JMO
 
What I have found over the past several years of fighting the problem of no start when hot is the NAPA resistor or any other one like it that I have bought over this past period. And that is when they heat up the resistance goes up and the voltage goes down. The voltage is usually enough to keep the engine running, but once you shut it off, the voltage is to low to start the engine. The resistor cools down, the resistance goes down, and then you can start the engine. That is why I recommend a new solid state resistor with heat sink to keep it cool. The extra benefit is that the engine actually runs better with the correct voltage to the coil.

Side note: NAPA resistor is $10 with same old problem, Newark is $5 and solves problem, but is not original for show.
 
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