Model B ignition question

If anyone is interested in using the timing indicator device shown in reply no. 9 above:

1. After securely fastening this device while using an "A" timing cover, just rotate the engine until the timing pin slips in the timing gear at zero degrees, (TDC); and provide a vee mark on the circumference of the crankshaft pulley directly under the zero (0) degree marking on said timing device.

2. When the crankshaft's vee mark is later positioned under this timing device's zero (0) degree marking, one may or may not want to use this same zero (0) setting in the future to verify A distributor timing.

3. Next, with same timing device securely fastened while using an "A" timing cover, and while using a "B" distributor, immediately after the timing pin slips in, rotate engine counter-clockwise until this same crankshaft pulley vee mark is positioned directly under the 9.5 degree mark on the above mentioned timing device.

4. Then, remove the distributor body from the "B" distributor and adjust the distributor cam so the points just begin to open.

5. Next time one wants to re-set "B" distributor timing, set vee mark under the timing devices 9.5 degree mark and adjust "B" distributor cam such that points just begin to open.
 
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The initial B ignition timing occurs at 19* BTDC crankshaft degrees. The crank position is the reference not the camshaft position. You can put the crank at 0*(TDC) using the A cover and then back the crank 19* and set up your timing mark. Forget about 9.5*, it will screw you up.
 
harleytoprock said:
The initial B ignition timing occurs at 19* BTDC crankshaft degrees. The crank position is the reference not the camshaft position. You can put the crank at 0*(TDC) using the A cover and then back the crank 19* and set up your timing mark. Forget about 9.5*, it will screw you up.
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I agree, correct timing for the Model B is 19 crankshaft degrees. if you do as Chauvin describes in clause 5 in the above post and set timing at 9.5 at the crankshaft indicator it will be 4.75 degrees at the cam gear and you will be running to far retarded
 
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Please note, per reply no 21:

3. Next, with same timing device securely fastened while using an "A" timing cover, and while using a "B" distributor, immediately after the timing pin slips in, rotate engine counter-clockwise until this same crankshaft pulley vee mark is positioned directly under the 9.5 degree mark on the above mentioned timing device.

1. Per above paragraph 3 in above reply no. 21, if one looks at and/or buys the same dial indicator shown in above reply no. 9, one can see on said device, numerical degree divisions from 0 - 30, which when said device is installed, it occurs immediately above a "Ford" 5" diameter "pulley" .

2. These incremental 0 - 30 degree divisions measure incremental degrees on the "Ford" 5" diameter pulley and "not" 0 - 30 degrees on the 50% smaller diameter crankshaft gear.

3. Because the distance or radius from the center of the timing gear to the timing pin depression in the timing gear is 2.5", the circle scribed by the depression in the timing gear has the same 5" diameter circle as that of the "Ford" 5" pulley, the incremental degree markings on the above mentioned timing device indicates the exact same degrees on the 5" diameter timing gear circle as that of the 5" diameter "Ford" crankshaft pulley; hence the timing device increments are actually measuring "timing gear" degrees.

4. But, because the timing gear has 50 teeth and the crank gear has 25 teeth, every time the timing gear makes a 360 degree revolution, the crankshaft gear makes (2) 360 degree revolutions; so when the timing gear rotates 360 degrees, the crankshaft rotates 2 x 360 degrees; and when the timing gear rotates 9.5 degrees, the crankshaft is rotating 19 degrees.

5. Hence, with the above timing device marking 9.5 degrees on the 5" diameter of the timing gear, and with the above timing device marking 9.5 degrees on the 5" diameter "Ford" crankshaft pulley, and because of the 50/25 teeth ratio, crankshaft gear is rotating 2 x 9.5 degrees = 19 degrees.

6. Furthermore, with the 5" diameter timing gear circle, the distance between the timing pin holes in the (2) different A & B timing covers is 0.4143" and the distance between a 0 degree mark and 9.5 degree mark on the "Ford" 5" diameter pulley is the same 0.4143" .............. but ............. the crankshaft is turning twice as fast.

7. If the engine is rotated counter-clockwise as described in paragraph 3. of reply No. 21, and the (0) degree TDC vee mark in positioned under this same timing device's 19 degree mark, and the B distributor cam is positioned to where the points just begin to open: Caution: Please do not turn on the ignition switch and try to crank this engine with a hand crank.
 
Thanks guys. I just set the crank at 19 degrees, wired up a temporary fuel pump and coil, and vroom. Smooth idle, smooth through the range. Seems peppy in the garage, but the flywheel is lighter, so it may just have less to push.

I'm happy.
 
Works every time .... had my B distributor set up at 19 degrees BTDC over 50 years ago ..... using same B distributor at present ....... was never afraid to use a hand crank ..... Model B's came with hand cranks.
 
Chauvin,

In post #21 you say to set the timing at 9 1/2 Deg.:(

In post #24, you say to set the timing at 19 deg.:)

In post #26, you say "Works every time". :confused::confused::confused::confused:

I think it is safe to say when using a "B" distributor, set the initial ignition timing at 19 Deg. BTDC.

Chris W.
 
Hi Chris,

In #21, #24, and #26, timing of engine crankshaft is 19 degrees BTDC.

In #21, #24, and #26, setting timing is described while only using the "timing device" shown in reply no. 9.

In #21, #24, and #26, the same circular distance measured between the timing pin hole in the A timing cover and the B timing cover was used to measure the circular distance between the two (2) vee marks on the crankshaft pulley.

Some may want to alter this circular distance when marking the crankshaft pulley; but I always left this circular distance the same as the difference between the A/B timing pin circular measurements.

Hope this helps.
 
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H. L. Chauvin said:
Hi Chris,

In #21, #24, and #26, timing of engine crankshaft is 19 degrees BTDC.

In #21, #24, and #26, setting timing is described while only using the "timing device" shown in reply no. 9.

In #21, #24, and #26, the same circular distance measured between the timing pin hole in the A timing cover and the B timing cover was used to measure the circular distance between the two (2) vee marks on the crankshaft pulley.

Some may want to alter this circular distance when marking the crankshaft pulley; but I always left this circular distance the same as the difference between the A/B timing pin circular measurements.

Hope this helps.
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Chauvin;

No, this really does not help.

You say in your post #21, Paragraph 3 to rotate the crankshaft to the 9 1/2 mark on the scale when using a "A" timing cover from where the pin will fit into the detent in the timing gear.

When using a "A" timing cover, the pin will fit into the detent of the cam gear when the engine is at TDC. From this point, turning the crank 9 1/2 degrees using the scale will only advance the engine 9 1/2 (crankshaft) degrees.
You need to rotate the crank to the 19 Degree mark on the scale.

The scale is set up for CRANKSHAFT DEGREES. All the add on scales I am familiar with are all marked in degrees for a stock Model A crank pulley.

The pin in the detent (when using a "A" cover) is TDC. Rotating the crank 19 degrees from that point will result in the position you want to set initial timing (19 Deg. BTDC).

Rotating the crank only 9 1/2 degrees will result in only 9 1/2 degrees BTDC. This is NOT where you want to set initial timing.

I do not have a crank pulley here where my computer is but as you say, if the pulley is 5" dia., the distance between the TDC mark on the outside edge of the pulley and 19 degrees will be apx 0.84 inches. Therefore, the distance between "0" and "19" on the scale should also be apx 0.84 in.

I hope this helps,

Chris W.
 
All this futzing with degree markers? You can have it both ways. Attach a B-timing cover to the engine after setting it at TDC using the A cover. Next, drill a depression in the cam gear for the B timing pin. Then reattach the Model A timing cover. This will leave you with two hole depressions in the cam gear for using either the A or B distributor, provided you can remember which is which. Setting it for the B distributor will be more accurate than rotating in backward, as some suggest.
 
ursus said:
All this futzing with degree markers? You can have it both ways. Attach a B-timing cover to the engine after setting it at TDC using the A cover. Next, drill a depression in the cam gear for the B timing pin. Then reattach the Model A timing cover. This will leave you with two hole depressions in the cam gear for using either the A or B distributor, provided you can remember which is which. Setting it for the B distributor will be more accurate than rotating in backward, as some suggest.
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Or get the timing cover with the large boss and drill / tap a hole at each end of the boss. Just mark which one is A & B.
 
Hi Chris,

Again .................... most sincerely ....... "Hope this helps!"

You are right .............. and I am wrong.

Just returned from garage to verify my known A timing cover, my known B distributor, and my known same timing device per above reply no. 9 bought about 6 years ago.

1. Turned engine clockwise until timing pin slipped in at formerly verified engine TDC.
2. Looked at crankshaft pulley & saw vee mark in the pulley.
3. Vee mark was opposite zero (0) degrees on the above mentioned timing device.
4. Hooked up a multi-meter to both sides of points and turned crankshaft counter-clockwise.
5. Turned switch "ON".
6. Rotated crankshaft clockwise until points opened, needle moved on multi-meter, and instantly heard spark at end of coil wire.
7. Looked at crankshaft vee mark and read degrees on above mentioned timing device ....... right at 19 degrees.
8. Had not checked timing in 6 years; however, it never moved.

Thanks Chris, and others above for taking the time to offer and post corrections and thoughts.

Apologies for incorrect assumption.
 
Chauvin;

No need to apologize, we all have made assumptions when working on this old stuff and later found things were different than we thought or remembered.

The most important thing is for people like you who have a lot of knowledge about these cars continue to help those who are less knowledgeable or new to the hobby.

Our hobby will only continue to attract new people if the more experienced owners help the less knowledgeable learn about the cars and how to repair and maintain them.

Carry on,

Chris W.
 
Hi Chris,

Thanks for very kind words, and I also admire your always helping others.

I just noticed that on my fridge, there is still a "Save the Date" note with my oldest son's wedding date of July 9, 2009.

I took them to their wedding in my 1930 Town Sedan and that's the last time I timed my B distributor ...... the morning of the wedding.

At least I have "written confirmation" that I got one (1) thing right ........ as mentioned, per reply no. 24 ....... I remembered that I last timed my B distributor six (6) years ago.
 
Let me get this straight, The Mod B engine starts with 19 deg. of advance, while the Mod A starts on zero? The more I read, The confusered I get!
Terry
 
Hi Terry,

And, per your reply #38 ...... that is not all ........ Depression Days was a time when people had to "Make Do" ........ e.g., not to further complicate A/B engine and parts swapping matters:

1. One could also run a Model B engine, (which came with 19 degrees advanced timing with its Model B timing cover with an advanced timing pin setting, with a Model A manual advance distributor, with initial timing set at zero (0) degrees; and/or

2. Run this Model B engine with a Model A distributor, either with a Model A or Model B timing cover, and/or a Model A or B carburetor, and/or Model A or B head; plus,

3. With a B engine in a Model A vehicle, one could bypass the Model B fuel pump and run the B engine in a Model A with a Model A gravity flow gas tank.

4. On a slightly jovial note, could this A/B engine timing and parts swapping conundrum have possibly caused Model A & B Ford owners and mechanics to start drinking so much that they demanded that Prohibition be cancelled not too long after the Model B's came out ?
 
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