Model B distributor on Model A engine?

M

mcgarrett

Well-known member
What are the Pros & Cons of running a Mode B distributor on a Model A engine? Appreciate all the myths, tales, rumors, and facts! :)
 
The automatic advance mechanism of a B distributor does not advance far enough to suit the lower compression Model A engine.
The Model B engine has a reputation of cracking the block. Most people blame thin castings for that but I'm not so sure that is the issue. The B distributors by now are all pretty much worn out. Even in the day, after a few years, they didn't advance properly. I have 3 of them and none of them work worth a damn. The worn mechanism doesn't allow it to advance as far as it should so the engine ran retarded. A retarded engine runs hot. Hot engines crack the block.
Use that B distributor as a door stop or paper weight.
 
I run one in my '31 RDPU and like it because you don't have to fool with the timing lever. Remember you will need a Model B timing cover if you want to time it "by the book". I have attached a photo showing the timing pin location at the top of the oval boss. The boss on the Model A was round. There are "work arounds" to using this cover but I have never needed them (see archives). I modified a quality Model A condenser to use in it by adding a pig tail and elongating the hole in the tab at the end of the condenser. Renner's Corner is the place to go for Model B distributer parts ((734) 428-8424)

Charlie Stephens
 

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Thanks guys for the candid responses. I picked one up today at a swap meet and noticed it's missing the breaker plate and apparently they are not easy to come by. Also, it seems as though the B distributor has a rather sinister reputation, and since I don't want to have to source and install a B timing cover I think I'll pass.
 
mcgarrett said:
Thanks guys for the candid responses. I picked one up today at a swap meet and noticed it's missing the breaker plate and apparently they are not easy to come by. Also, it seems as though the B distributor has a rather sinister reputation, and since I don't want to have to source and install a B timing cover I think I'll pass.
Click to expand...
The source I referenced probably has a breaker plate.

Charlie Stephens
 
My take is that the B distributor can be made to work properly, but it's sort of like a Mallory in the sense that you have to scrounge hard-to-find parts, learn about its quirks, and then commit to tinkering with it and testing it over time until you dial in the performance you want. They rarely work out of the box. If you want plug-and-play centrifugal advance, get the Nu-Rex advance device.
 
Repaired properly, the B distributor is very reliable and will work very well. The advance curve is well suited for not only a stock A engine with stock or a high compression head but also the Burtz engine with a 6.5:1 compression head.

The key to being able to time a B distributor correctly is to have a TDC mark on the front pulley and a timing scale so you can use a timing light. I am currently restoring eight B distributors and when finished I will use my Sun distributor machine to calibrate the advance mechanism.

Renner's Corner has some parts for the B distributor. For one to be rebuildable, you need a good usable casting, upper plate and advance mechanism. Ronner's can supply the shaft, bushings, springs for the advance mechanism and small parts kits. Cams are available, and you can use "A" condensers. The one thing that is in very limited supply are new B points. While similar, A points cannot be modified to work. I have had good success converting a B distributor to use "modern" points.

Once properly rebuilt and calibrated, B distributors are reliable and work very well. I much prefer a good B distributor over a new FS distributor any day of the week.

My experience,

Chris W.
 
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CWPASADENA,
Very interesting feedback, thank you. I'll keep all this in mind and try to accumulate the missing parts and might give it a shot later on. I noticed that Renner's doesn't show to have the breaker plates or points in their inventory.
 
I would check with Mill Works and be sure they are in stock
and if they actually come with the spring as shown, most
B points do not come with the spring.
 
Bob C said:
I would check with Mill Works and be sure they are in stock
and if they actually come with the spring as shown, most
B points do not come with the spring.
Click to expand...

You definitely will need the spring. I found that later service replacement parts were more likely to include the spring. You can also watch eBay for any B-12199 listings. They come up sometimes, and even if the points are bad you might could rescue the spring.
 
alexiskai said:
My take is that the B distributor can be made to work properly, but it's sort of like a Mallory in the sense that you have to scrounge hard-to-find parts...
Click to expand...


Hello... I have that Mallory distributor for the Ford Model B engine! It is the distributor for a very special B engine I found fresh rebuilt at a vintage engine shop some time ago. "Just had to have it!" I had some friends that worked at Mallory and so I sent it in for a checkout. Mallory did a full service to it for me and installed new point set, etc. I about fell off my seat at my workbench when I got the invoice back from them... Amount Due: $12.00! :)


ready to go, but has not fired a plug yet
 

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I have a Model B distributor and timing cover I will sell if as a set if anyone is needing one. Both are in great shape.

I found a Mallory YA-11A shortly after I got the B distributor and plan to run it instead.
 

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It may be fun, but when you go to sell your car you will understand the reason someone might question “WHY”.

A well sorted out original car, or a correctly restored car will bring the owner much pleasure during their ownership but also at time of sale.

Over the last 90 years most of these cars have been owned by many different people. Some knew how to maintain them. Others were “shade tree mechanics”.

I hope there are still owners out there that understand we are just caretakers. These are really antiques.

Your car, do what you want. Don’t complain when you want to sell it, and can’t get the price of other better maintained cars.

My soap box again. I’m old so it’s a good fall back.

Enjoy.
 
There are several types of Model A owners/buyers
1 - The fine point guy whose car sits under a cover in the garage and goes to an occasional show in an enclosed trailer.
2 - The guy who wants his car 100% stock and enjoys putting around at 40 mph
3 - The guy who has added some improvements while keeping the stock look to improve drive ability - HC head, touring cam - alternate distributor - overdrive - etc
4 - the guy who goes beyond 3 with Stromberg carbs, bigger cam, 7:1 head, 5 speed trans, 16" wheels, radials, etc.
5 - the guy who lost the fenders and a couple inches from the roofline. It can have a 4 or V8.
MAFCA recognizes the varied owner tastes and provides judging for all but #5.
 
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