Model A Ford - Upgrading to Model B Distributor - Part 1
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- Опубліковано 29 чер 2024
- The Model B car, which replaced the Model A in 1932, was the first in Ford's lineup to feature mechanical spark advance. Model A owners have a long history of trying to adapt the distributor from the B for use in the A, but after 90 years, it's poorly documented and most units are in bad condition. In this video I describe what to look for in a restorable B distributor, and I show step by step how to assemble one. In Part 2 (coming later this year), I'll show how to test the performance of the B's mechanical advance and some options for adjusting the timing curve to suit the needs of Model A drivers.
If you want to learn more about the Model B car itself, @32modelbford39 has been posting some ride-along videos. - Авто та транспорт
Well done. For me, part of the enjoyment of driving my Model A is advancing the timing myself. Just like the manual brakes and steering, it's part of the experience.
There are a lot of people who want the authentic 1928 experience. Myself I want more like a 1936 experience. Luckily there's room in the world for both.
Great video and Channel! Lots of good informative information! Thanks for the shoutout! I appreciate it!👊🏻
Fantastic - I wish that you would show tightening the screws so viewers have an idea of how to correctly torque them.
The only one you maybe need to put a little oomph into is the cam screw. Otherwise hand tight should be fine. I tend to cut the parts where I'm attaching screws - first because I'm sort of a clumsy guy and second because the overhead camera means I would need to hold the workpiece at an odd angle so you could see what I was doing.
Very nice!
As far as those pivot pins go everything in the distributor is hardened and wear it's not too likely but you can grip the pins with pliers and turn them 90° and get a new surface for the weights to act against with both the plate and the yolk pins.
Additionally, when centrifugal force acts on the weights, they spin out and they're tight against the pin.
Hi Dave, thanks so much for your comment. Really could not have done this without your prior research. Re: the pins, mine were *really* worn, to the extent that I couldn't be sure they would hold position, even with centrifugal force pushing the flyweights out.
I've reached out to Vince Falter to see whether he might have some reference NOS examples of the weights and springs for use in the next video, where I look at what timing curve the B produces.
Thanks Straight Ahead ✌😎
Tried the B distributor but found the reissue of Phillips Spark Advance tec made in 1930s by Nurex better. Petronix ignition replacing the points makes for reliable and more forgiving application. Use the common A distributor. Like the old look but not old time consuming, fidgeting and frustrating issues of which some get satisfaction overcoming.
Yeah, if you keep compression under 6:1, the Nu-Rex is a lot more effective.
You should always use a cam screw with a hole down the middle so you can lubricate the yoke that spins on the small diameter of the shaft. Otherwise you have to remove the cam screw to lube the yoke a drop of 3 in 1 oil every 200-500 miles is plenty.
Good tip
Very well done video. Clear concise instructions on rebuilding a B distributor. I believe your explanation of the purpose of the condenser and the production of the spark is just a bit off, if I may. The longer dwell, the time the points are closed, allows the primary windings of the coil to draw more current creating a stronger magnetic field. The condenser absorbs the the energy, or arcing, that would occur as the points open. The arcing would interfere with the instantaneous collapse of the magnetic field of the primary windings that induces a much larger voltage in the secondary windings which directs that energy to the spark plugs. If the condenser is weak the points will eventually burn from the arcing and the spark will be much weaker or non existent as the primary magnetic field only partially collapses or not at all. The B condenser has more capacitance because the longer dwell time means more current flowing to the primary windings and more current trying to arc across the points. I'm looking forward to more of your videos.
I think I agree with all this? What's the timestamp of the part you thought needed more clarity?
@@alexiskai I must have cut to your video on Condenser Testing and Theory that you mention at ~ 32:14. In that video, when you describe the function of the condenser, I believe you may be conflating its function with the capacitors in a Capacitive Discharge Ignition. In the Kettering system the sole function of the condenser is to absorb the energy as the points open so they don't arc. You are correct in that no current flows into the condenser because it represents a higher resistance than the closed points. Once the points begin to open the current flows into the condenser instead of arcing across the small space between the points. When the current stops flowing into the condenser the magnetic field suddenly collapses and produces the high voltage spike in the Secondary windings and delivers the spark. So the condenser really only there to absorb the arcing and assist the collapse of the primary windings. One reference on Kettering systems is here: www.ratwell.com/mirror/users.mrbean.net.au/~rover/ketterin.htm.
@@thomasdejohn9347 I think I see what you're talking about. So the point of clarification is, does the condenser act *only* to prevent arcing at the contacts. I think that is by far the most important action, but it's not the only thing going on. If that were the only factor, it wouldn't really matter how "large" the condenser is, i.e., how high its capacitance. But that's not true in practice. Experiments with other Kettering system engines have shown that there is an optimal size (in practice, a range of sizes) for a condenser for a given engine. The condenser should be large enough to prevent arcing, but no larger. The reason is that a larger condenser will provide a path for the current for a longer time after the points open.
The Kettering system is a type of tuned circuit, meaning a circuit containing an inductor and a capacitor. When the points open, current resonates (oscillates) back and forth between the coil and the condenser. The amplitude and frequency of the resonance are correlated. As the condenser gets larger, it absorbs current for longer, and the "back-pressure" voltage with which it feeds current back into the circuit decreases. This causes the amplitude and frequency of the resonance to decrease. This is important because the amplitude of the resonance is what creates the voltage in the secondary winding. Higher amplitude = higher spark voltage.
There's a great demonstration of this in antique outboard motors that I will link to below. On p. 6 of the linked document, you can clearly see how the size of the condenser affects the spark voltage. That's why I mention the "back-pressure" effect of the condenser in the video and I think that's what you were picking up on.
wrcoutboards.org/wp-content/uploads/2020/04/Part3_Sizing_Condensers_Correctly.pdf
@@alexiskai Thanks, I read that article and yes your reference to a "back pressure" effect of the condenser is what I found misleading. The article you've cited explains that the collapse of the primary magnetic field generates several hundred volts in the primary and tens of thousands of volts in the secondary to cause the arc across the spark plug gap. Those several hundred volts generated in the primary would also arc across the point gap if it were not for a condenser of the right capacity to absorb just enough of that energy to prevent the arc on the points but not enough to lower the primary voltage amplitude enough to adversely affect the secondary voltage. There is essentially no discussion of a "back pressure" or any "feeding back" into the circuit. The article concludes " . . . that the condenser size is FAR from critical; anything large enough to quench the arcing cross your points is all you need."
@@thomasdejohn9347 He doesn't discuss it in print but you can see in the oscilloscope diagrams he includes that the resonance is there. How could it exist if there weren't a reverse voltage across the coil primary winding caused by the capacitor discharging? This section of the Wikipedia page on LC circuits gives a nice summary: en.wikipedia.org/wiki/LC_circuit#Operation
I agree with you that dissipating the arc at the points is 95% of the job of the condenser, but insofar as I was trying in that video to give a reasonably complete description of the electrical activity, it would be misleading not to discuss what happens when the condenser discharges. I might have given it too much prominence.
You say in order to set initial timing on an A to B timing, you need a B valve cover.... don't you mean a B timing gear cover?
The B valve cover won't fit the A , but the B timing cover, with it relocated timing pin will.
Did I say valve cover? Oops. Thanks for the correction.
The sound you heard was the over the head sound.Ill stick with tried and true that a feeble braine understands .Excellent information however.
Oh no! I really try to explain everything clearly but sometimes I fall short. Let me know where I lost you.