Need some distributor lessons

[Fordestes]

I have a 41 ford v-8 distributor Is this the most preferred and what model do they call it an 11-A or 40-B ? it has the smaller cam than the earlier model , is the advance better than the earlier unit?
thanks Fordestes

[Kahuna]

Fordestes
If you have a true 41 distributor, it will have the 11A advance mechanism in it.
The advance mech is marked.
It is IMO, the best to use.
Jim

[Fordestes]

the only numbers I can find on all three I have dis-assembled is 68, nothing else besides ford logo on the breaker plate. does 68 mean anything far as curve etc.?

[petehoovie]

68 was the Model Number for the 1936 Ford....

[BUBBAS IGNITION]

68 is a 22 degree unit as well.
I see no difference in a 68 and a 11A.
As long as you have the small cam with indiviudal contacts thats the good one.

[SofaKing]

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Originally Posted by BUBBAS IGNITION

68 is a 22 degree unit as well.
I see no difference in a 68 and a 11A.
As long as you have the small cam with indiviudal contacts thats the good one.

Can you post photos please that illustrate the size and contacts you refer to for people unfamiliar with the topic?

[Fordestes]

Thank Bubba, I will proceed wit the cleaning and lube of the distributor, also what are the numbers for new points from napa and which condenser is a good one for trouble free operation?

[BUBBAS IGNITION]

Originally Posted by Fordestes

Thank Bubba, I will proceed wit the cleaning and lube of the distributor, also what are the numbers for new points from napa and which condenser is a good one for trouble free operation?

CS47 for the point set

[uncle buck]

Originally Posted by BUBBAS IGNITION

68 is a 22 degree unit as well.
I see no difference in a 68 and a 11A.
As long as you have the small cam with indiviudal contacts thats the good one.

Bubba,
Are you referring to the 32-36 early vs 36 late and newer point design?

[Fordestes]

my dist .is a 37-41, v-8, has small cam and 68 on the internal components.

[35fordtn]

Jim school me as every single 68!dizzy I’ve ever strobed advances between 16-18 degrees compared to the 11a which always advances 21-24 degrees??

[Lawrie]

The advance curve is different on the 68 to the 11a,
Lawrie

[35fordtn]

Lawrie I know the curve is different but so is the amount it advances.

[Lawrie]

I,m not home so can’t look up my stuff,but I think they advance to the same amount ,but at a different rate
Lawrie

[35fordtn]

Lawrie,
On all I’ve ever done the base line on them all in terms of cam degree are as follows
40a 11 deg
40b 8 deg
68. 8 deg
99a (very rare) 10deg
11a 11 deg

I personally think there is a notable improvement between the 68 and 11a.

[Lawrie]

In my ford service bulletin books it lists all the advance info!start degrees,finish degrees, total advance ,and there you see there is a big difference in them,as I said I,m away from home so can’t look up them.
B,it the 11a is the best of the two,
Lawrie

[BUBBAS IGNITION]

Originally Posted by 35fordtn

Jim school me as every single 68!dizzy I’ve ever strobed advances between 16-18 degrees compared to the 11a which always advances 21-24 degrees??

Mike , Will do as i have two apart going back together right now , just havent noticed much difference in the 68 and 11 As.......I have parts for both will get a run up this week and check again......

[Fordestes]

Thanks all who responded, Bubba we will be looking forward to the results
many thank for your effort.
fordestes

[BUBBAS IGNITION]

Guys got a few minutes this morning to look at a few parts.
I might have mis-spoke a little bit by saying the model 68 and the 11A were the same degrees??
Heres the Bulletins from the Ford Bible regarding all (but the 41 dist) and like Mike stated the 68 is rated at 18 degrees at 1900 rpm.
Looking over the workbench this morning i have one of the 68 and a 11A unit going together this week. Will run the curves on the machine as time permits.

Some observations and measurements show the cam assemblys, the two shafts and the brake rings. Appears the 11A and 68 cams ( small) weights etc are the same. Shaft slots measure the same as well, although may be slight variation in slot locations????
The two brake rings have different profiles and slots ( this could be the major difference in the two).
Did Henry use the 11A in the 41 models and then carry the part into the 42 crab???
My books say very little in regars to 41-42 distributor changes?????

[35fordtn]

Jim,
Thanks for your observations.. The only difference in my opinion in the 68 vs 11A weights is the spring tension.

I believe ford redesigned the brake ring (or index plate as I call it), when they redesigned the shaft to allow more advance. I believe the shaft is all that controls the amount of advance, and weights natually control the rate. I have run a 11A index plate on a 68 distributor with no change, however running a 68 index plate on a 11A distributor limits the advance by two degrees.

Somewhere I have the Ford prints and engineering drawings on the different distributor parts. The 21A distrubutor used the 11A weight and index plate with the only change being the shaft.

What is that "901" distributor on the chart??

[BUBBAS IGNITION]

Is the 901 a Lincoln 12????

[35fordtn]

Jim,
All the Lincoln dizzys I have have H, HB, or 16H stamped on them... maybe tractor??

[BUBBAS IGNITION]

SOME MORE DISCUSSION REGARDING EARLY FORD ADVANCE CURVES...

A couple pics from some morning work. I think Ford has done a great job sitting this one up. It appears the weights have a bearing on top and a pin on the bottom. The 11A slots are a little different from the module 68..
Heres the exact curve from the model 68. And a couple pics of the upper bearing plate and lower pin plate . Well designed for proper curve...

[35fordtn]

Jim, If I am seeing it properly, your graph depicts the 68 beginning its advance curve right off of 500 rpms. Do you tamper with the springs at all? In stock form a 11A seems to advance at or just above the 500 rpm range, but the 68's much later.. Thats the main reason I prefer a 11A over a 68.. when stating rpms I am referring to crank rpms not distributor rpms..

[RobR'35]

Ford had good prints and specs on everything they produced. It suprises me there aren't prints and specs found yet today that depict everything involved with all these distrbutors.
Weight sizes in weight and shape, spring tension specs.

[BUBBAS IGNITION]

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Originally Posted by 35fordtn

Jim, If I am seeing it properly, your graph depicts the 68 beginning its advance curve right off of 500 rpms. Do you tamper with the springs at all? In stock form a 11A seems to advance at or just above the 500 rpm range, but the 68's much later.. Thats the main reason I prefer a 11A over a 68.. when stating rpms I am referring to crank rpms not distributor rpms..

This was my third one this week and all seemed very much the same (all 68s), my numbers at the bottom are in 500 rpm jumps. Note the slow linear rise to approx 1500 then the rise time from 8 to 14 degrees and then the final jump to 16 degres at 2500.
My next batch is early strap point units and i will compare them then get us some more discussion on the 11A......
I never mess with the springs , just make sure they are straight etc.....

[rotorwrench]

The green bible lists the 68-12176 advance unit but in the description column it states "replaced by 11A-12176". The 11A-12176 was the replacement part for most of the front mount distributors up thru 1948. If the old 68 type is still serviceable then it can be used but the little bit more advance given by the 11A type won't hurt anything on the older engines.

[35fordtn]

Jim,
I rebuilt and ran 2 68's and 3 11A's on the Sun Machine / KRW fixture today.
Both 68's advanced 16 degrees and began there advance at around 875 rpms finishing out around 1400. The 11A's all advanced 23 degrees beginning at around 450 rpms and finishing off around 900. The 11A's all had NOS shafts and weights.

As a side note I have run into NOS 11A shafts that are "clocked" wrong causing you to have to run the timing indicator all the way in the bottom retard position to achieve 4 degrees initial timing. I have run into 13 NOS shafts that way.. Likely mis-manufactured, thus why I think it imperative to use actually check the timing rather than relying on the marks.... Just my pea brained opinion!

IMG_3591.JPG

[BUBBAS IGNITION]

Originally Posted by 35fordtn

Jim,
I rebuilt and ran 2 68's and 3 11A's on the Sun Machine / KRW fixture today.
Both 68's advanced 16 degrees and began there advance at around 875 rpms finishing out around 1400. The 11A's all advanced 23 degrees beginning at around 450 rpms and finishing off around 900. The 11A's all had NOS shafts and weights.

As a side note I have run into NOS 11A shafts that are "clocked" wrong causing you to have to run the timing indicator all the way in the bottom retard position to achieve 4 degrees initial timing. I have run into 13 NOS shafts that way.. Likely mis-manufactured, thus why I think it imperative to use actually check the timing rather than relying on the marks.... Just my pea brained opinion!

Attachment 370678

WOW someone would really have to work at clocking the plate incorrecty as the shaft, tang and advance plate are indexed with a machined flatspot. Send me a couple pictures of that when ya get time.......

I am fighting point bounce on a early Model18 unit this morning, finally got it fixed with new set of aftermarket (NOS) contact points.....

[35fordtn]

Jim, Ill get a faulty shaft and shoot a photo on here tomorrow in comparison to a good one. The plate with the two slots are clocked wrong in comparison to the tang.

Them darn early points have that tenancy to bounce like a basketball. I hate them.. My favorite old brand of the Early points is tungsten.. The easily run up to 5500 in many instances without bouncing.. Ive never been able to get even NOS Ford points to act properly above 3800 ish.
Jim, Have you ever had any luck out of the Repro early points? I gave up on them after three failed attempts of trying to set dwell, but that was two years ago.

[BUBBAS IGNITION]

These are the last of my prefered strap points, they have worked pretty good about 90% of the time. When these are gone i am going to need some more from somewhere. Good news is that i dont use a lot of the early distributors. If the customer is serious i convert to 11A or 68 and use the small points.

[BUBBAS IGNITION]

aftermarket box of points.......

[35fordtn]

Jim when you run I’ve got plenty of good ‘uns