Model B distributor

daren007

Well-known member
My B engine with A distributor does not like advance at idle. A little is ok but more and she runs lousy. She is timed properly at TDC. while driving 1/3 advance seems to be the sweet spot for overall driving. If I install a B distributor I am told the timing should be now at 19 degrees before the mechanical advance takes over. This seems excessive. I would think it will affect my idle plus would I get a kickback on starting?
 
It was evidently not excessive as many B-distributors have been installed in Model-A engines over the years. I have never had to crank mine by hand but have been assured that kickback should not be a problem provided one held the crank correctly, and Ford supplied a crank with the Model-B for both timing and starting.
 
I have a model B distributor on my A engine. Best thing I ever did, idle in consistent no issues with going uphill .

Jim m
 
B engine with an A distributor, but what timing cover do you have?
Remember, a B cover is advanced when the pin drops into the dimple.
 
B engine with an A distributor, but what timing cover do you have?
Remember, a B cover is advanced when the pin drops into the dimple.

To illustrate Tom's post. The picture is a Model B timing cover. The timing pin is located in a tapped hole at the top of an oval boss. The Model A timing cover had a tapped hole in the center of a circular boss. A very few timing covers were made for the Model A as replacement parts with the tapped hole at the bottom of the oval boss.

Charlie Stephens
 

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I have an A front cover but would use a timing indicator. As I read the B is timed 18 degrees BTDC opposed to the A's TDC. This would mean the B is firing before TDC if so I would expect a kickback on starting.
 
18 degrees won't kick back on the stock engine. I've even started mine with about 30 degrees advance when I forgot to retard the spark lever.
 
Doesnt matter if its a touring cam,B distributor has the correct advance curve.Total advance is about 24 degrees,perfect for an A ,especially with a high compression head.Stock B points are getting scarce but Renners Corner retrofits them with modern points..drill through the lube port(its usually blocked by the bushing) and drill the cam screw so you can lube the upper shaft.And throw your spark control lever away...
 
We can supply new sets of B points if anyone requires them , Derek in a cold freezing NZ back from the hot Reno meet ,
 
Doesnt matter if its a touring cam,B distributor has the correct advance curve.Total advance is about 24 degrees,perfect for an A ,especially with a high compression head.Stock B points are getting scarce but Renners Corner retrofits them with modern points..drill through the lube port(its usually blocked by the bushing) and drill the cam screw so you can lube the upper shaft.And throw your spark control lever away...

Regarding the oil port that is blocked by the bushing: that is what I have done in the past but was recently told that Ford had started installing oil impregnated bushings of the Oilite type during the Model B period. These are made of porous bronze that allow for oil to pass through to the bearing surface from the reservoir in the oiler port. Supposedly, you only need to drill a hole for access if you have installed non-porous bushings.

I wonder if anybody can cite a Ford reference to this bit of trivia?
 
I could find no mention of an oilite bushing in the Ford service bulletins '32-'37. The "B" distributor on my Model A had an oilite bushing installed when I rebuilt it. To my knowledge it had never been apart except for minor adjustments. It had no oil hole. Unfortunatly I ha to install the newer bushing and drill it for lubrication. It has worked well for many years now.
 
The key is finding one with good shafts,the upper and lower get galled from lack of lubrication.All model A engines can benefit from mechanical advance,detonation is one of the main causes of bearing failure,the hammer effect of detonation is increased with higher compression
 
when i rebuilt my B dist a couple yrs ago i put in new weights some one made that was supposed to change the advance to run better, anyone else use these weights??
 
I just bought a Model B distributor. I am planning to experiment with it in two different ways. 1) I am going to run it on s stock engine with the static timing set at 3 to 5 degrees BTDC. 2) When my second engine is built, with a 5:5:1 head, I will static time to TDC for less total advance. The stock engine will tolerate more total advance than the HC head. What I want to know is, what exactly is a high speed distributor cap for a Model B? I saw one on EBay and I had interest, because I find the quality of diamond shaped distributor caps to be horrible. However, it appeared to have no notch for the Model B timing indicator, or the advance window if used on a Model A. How does that work? It was a Nioff FF-71. I have taken a “modern distributor cap “ for a Model A and simply added a second index notch at 90 degrees to the Model A index notch. Now, I can use this cap on a Model B distributor. The advance window is still required for the Model B to clear the timing reference tab. Any inputs on this?
 
The Niohoff FF-71 that was on EBay is sold, gone. It was advertised that it fit a Ford Model B. There is a chart on this forum that confirms that number as a High Speed Model B cap. The cross reference was to an Ampco F-928. There are currently dozens of Nihoff caps on EBay, but those are not what I am talking about. I have the photograph on my phone. I am trying to figure out how to post it.
 
Bob, Thank You, that explains it! So, that is not an FF-71 cap. It’s just an FF-71 box. I actually bid on it when it was active. Now, I am glad I didn’t get it. It’s not the correct cap. That answers a lot of my questions. Does anyone have photos of a real FF-71? (A genuine high speed distributor cap for a Ford Model B)
 
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