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Old 10-16-2019, 12:13 PM   #1
Tom in SW VA
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Default Timing

Can bad timing cause overheating in a Model A? Asking for a friend.
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Old 10-16-2019, 12:15 PM   #2
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Default Re: Timing

Yes sir if the timing is off your engine will most likely overheat and boil over.
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Old 10-16-2019, 12:35 PM   #3
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Default Re: Timing

Try this....

PURDY'S WAY:

The timing instructions that I've seen are very confusing to the unknowing. One of the highly regarded timing instruction states that the sweet spot that the tip of the rotor must point at is only good to get you home. Many that try to follow this one keep trying to get the points to be just ready to open and end up moving the points cam. Moving the points cam off the sweet spot gets the distributor out of time . The points can be adjusted at anytime without loosening and moving the points cam. Ford specs for points gap is anywhere from .018 to .022 . Increasing points gap causes the points to open quicker and advances timing. decreasing points gap causes the points to open later and retards timing . The other popular timing instruction says that the rotor tip should point opposite the number one contact in the distributor. This causes some to think that the rotor tip should point at the number 4 contact in the distributor cap and the timing ends up 180 degrees out of time . Neither timing instruction goes in to any real detail about rotational backlash in the distributor shaft and which direction that the backlash must be in when the points cam is tightened. Actually points gap isn't that great of a cause for the model A timing being that far off , as long as the gap is within Ford specs. The three most important things about model A timing is where the rotor tip points , direction of backlash after the points cam is tightened and that the upper plate has full swing within the window in the rear of the distributor cap. Full swing meaning that the lever on the breaker moves all the way to the right side of the window for retard and all the way to the left of the window in the cap for advance.

I don't set my timing by the points. When the timing pin drops in the dimple of the timing gear, I adjust the points cam so that the trailing tip of the rotor points at the number one contact in the distributor cap. When the cam screw is tightened , there must be no clockwise rotation in the distributor shaft. There is always some rotational backlash in the distributor shaft, sometimes as much as 1/2 inch . In other words, all rotational backlash must be in the counter clockwise direction , where it will have no effect on timing. The reason being is that when the engine runs, the distributor shaft turns in the counter clockwise direction . If clockwise backlash remains, the engine will have to turn to catch up the backlash before the distributor shaft can turn. When the engine must turn before the distributor shaft begins to turn , this causes the timing to be retarded to what ever amount of backlash that had to be caught up before the distributor shaft could turn. This is why direction of backlash is so important. If there is 1/2 inch of backlash in the clockwise direction after the cam screw is tightened, the timing will be so retarded that the engine probably will not even run. If it does run it will be very weak and the exhaust manifold will get red hot. As for points gap, I don't bother with retarding the spark lever. I turn the engine untill the rubbing block on the points is on the highest point on the cam lobe, I don't mess with the cam screw . I loosen the lock screw on the points block and turn the adjustable point untill the gap opens to .022 and tighten the lock screw on the points block. Twenty two thousants is maximum gap acording to Ford specs and advances the timing to the max before there is danger of starter kick back. For me this gives quickest throttle response and gives the most time before the rubbing block on the points wears to the point that the points will have to be readjusted. When the points gap closes to less than .018 it will be time to readjust the points or you will begin to lose power and the exhaust manifold will begin to over heat . Truth be known, the model A will run good as long as points gap is within Ford specs of .018 to .022. Some prefer a more conservative gap of .020. The highly respected method is when the timing is on the mark with the spark lever fully retarded that the points should be just ready to open. This can be correctly arrived at by points gap adjustment. I don't feel that it is worth the trouble and feel that it causes the confusion that ends up with the timing being off. There is only about .004 thousants leway in points adjustment within specs, that minor amount will change constantly as the engine runs and the points block wears . Cam lube will decrease wear and the length before points adjustments will be necessary. I don't believe that the small amount that the gap will fluctuate will be that noticable untill the gap closes to less than .018 .
Last edited by Purdy Swoft; 01-15-2015 at 12:52 PM.
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Old 10-16-2019, 03:39 PM   #4
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Default Re: Timing

I agree with using Purdy's method; however, it's easier for me to follow when the procedure is broken up as follows:

Purdy Swoft's brake Adjustment Procedure:

Here is how I adjust mine:

I start with the center service brake cross shaft:

I disconnect the service brake rods on the adjustable clevis ends .

I set the pedal rod so that the plunger end is 1/16th of an inch from the inside rear of the center crossmember where it meets the plunger on the brake light switch on the 30-31

I then adjust the clevis on the pedal rod so that the pedal is at the top of its travel and prop it up until you get the service brake rods adjusted and connected .

I then adjust the adjusting wedges at each wheel until there is very slight drag but the wheels will turn fairly freely .

I then adjust and connect the service brake rods so there is no slack where the clevice end connects the brake levers . I pull the front brake levers back to remove all slack .

I then adjust the front service brake rod clevises so that the brake rod pins will JUST enter the clevis and front brake levers .

I then move on to the adjustment and connection of the rear brake rods:

Pull the rear brake levers forward to remove the slack and then adjust the clevices so that the brake pins will just enter . This setup will remove all of the slack in the brake rod connections so that the brakes will be ready to begin activation with the least amount of depression of the brake pedal .

This is only the setup and adjustments . If everything is good with the brake drums and other parts under the drums are in fairly good shape you will have good brakes . I always test mine in a sand or dirt driveway to observe the skid marks and readjust as necessary .

David Serrano
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Old 10-16-2019, 03:49 PM   #5
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Default Re: Timing

Sorry, I gave his break adjustments by mistake. Here is the timing.

Try this....

PURDY'S WAY:

The timing instructions that I've seen are very confusing to the unknowing. One of the highly regarded timing instruction states that the sweet spot that the tip of the rotor must point at is only good to get you home. Many that try to follow this one keep trying to get the points to be just ready to open and end up moving the points cam. Moving the points cam off the sweet spot gets the distributor out of time .

The points can be adjusted at anytime without loosening and moving the points cam. Ford specs for points gap is anywhere from .018 to .022 . Increasing points gap causes the points to open quicker and advances timing. decreasing points gap causes the points to open later and retards timing .

The other popular timing instruction says that the rotor tip should point opposite the number one contact in the distributor. This causes some to think that the rotor tip should point at the number 4 contact in the distributor cap and the timing ends up 180 degrees out of time .

Neither timing instruction goes in to any real detail about rotational backlash in the distributor shaft and which direction that the backlash must be in when the points cam is tightened. Actually points gap isn't that great of a cause for the model A timing being that far off , as long as the gap is within Ford specs.

The three most important things about model A timing is where the rotor tip points , direction of backlash after the points cam is tightened and that the upper plate has full swing within the window in the rear of the distributor cap. Full swing meaning that the lever on the breaker moves all the way to the right side of the window for retard and all the way to the left of the window in the cap for advance.

I don't set my timing by the points. When the timing pin drops in the dimple of the timing gear, I adjust the points cam so that the trailing tip of the rotor points at the number one contact in the distributor cap. When the cam screw is tightened , there must be no clockwise rotation in the distributor shaft.

There is always some rotational backlash in the distributor shaft, sometimes as much as 1/2 inch . In other words, all rotational backlash must be in the counter clockwise direction , where it will have no effect on timing. The reason being is that when the engine runs, the distributor shaft turns in the counter clockwise direction . If clockwise backlash remains, the engine will have to turn to catch up the backlash before the distributor shaft can turn. When the engine must turn before the distributor shaft begins to turn , this causes the timing to be retarded to what ever amount of backlash that had to be caught up before the distributor shaft could turn.

This is why direction of backlash is so important. If there is 1/2 inch of backlash in the clockwise direction after the cam screw is tightened, the timing will be so retarded that the engine probably will not even run. If it does run it will be very weak and the exhaust manifold will get red hot.

As for points gap, I don't bother with retarding the spark lever. I turn the engine untill the rubbing block on the points is on the highest point on the cam lobe, I don't mess with the cam screw . I loosen the lock screw on the points block and turn the adjustable point untill the gap opens to .022 and tighten the lock screw on the points block. Twenty two thousants is maximum gap acording to Ford specs and advances the timing to the max before there is danger of starter kick back.

For me this gives quickest throttle response and gives the most time before the rubbing block on the points wears to the point that the points will have to be readjusted. When the points gap closes to less than .018 it will be time to readjust the points or you will begin to lose power and the exhaust manifold will begin to over heat .Truth be known, the model A will run good as long as points gap is within Ford specs of .018 to .022. Some prefer a more conservative gap of .020.

The highly respected method is when the timing is on the mark with the spark lever fully retarded that the points should be just ready to open. This can be correctly arrived at by points gap adjustment. I don't feel that it is worth the trouble and feel that it causes the confusion that ends up with the timing being off.

There is only about .004 thousants leway in points adjustment within specs, that minor amount will change constantly as the engine runs and the points block wears . Cam lube will decrease wear and the length before points adjustments will be necessary. I don't believe that the small amount that the gap will fluctuate will be that noticable untill the gap closes to less than .018 .

David Serrano
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Old 10-16-2019, 05:09 PM   #6
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Default Re: Timing

Thanks David , I'll try that . Thanks for the thought and the post .
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Old 10-16-2019, 05:43 PM   #7
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Default Re: Timing

What do you guys think of the Nu-Rex timing wrench? I know you have to have a base to start with but it seems pretty simple to use.
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Old 10-16-2019, 05:44 PM   #8
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Default Re: Timing

Thanks , Burner 31 for posting post number 3
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Old 10-16-2019, 10:43 PM   #9
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Default Re: Timing

Quote:
Originally Posted by History View Post
What do you guys think of the Nu-Rex timing wrench? I know you have to have a base to start with but it seems pretty simple to use.
It works well, especially for a quick timing check or timing set by the side of the road.

You don't really need any "base" to use it.

Turn the engine over until the timing pin drops in the dimple, like normal timing procedure. Loosen the cam screw on top a little bit and use the wrench to turn the cam 1 or 2 times clockwise (to take slack out of the drive gears). Just as the wrench side begins to contact the 4th little pin on the top of the distributor body, you tighten up the cam screw. That's it!

You can leave the cam screw tight and put the wrench on the cam, then gently rotate it clockwise to check the timing any time you want.

The position of the timing lever is not important when using this wrench.

A very cool design.
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Old 10-17-2019, 12:04 AM   #10
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Default Re: Timing

Quote:
Originally Posted by burner31 View Post
Try this....

PURDY'S WAY:

The timing instructions that I've seen are very confusing to the unknowing. One of the highly regarded timing instruction states that the sweet spot that the tip of the rotor must point at is only good to get you home. Many that try to follow this one keep trying to get the points to be just ready to open and end up moving the points cam. Moving the points cam off the sweet spot gets the distributor out of time . The points can be adjusted at anytime without loosening and moving the points cam. Ford specs for points gap is anywhere from .018 to .022 . Increasing points gap causes the points to open quicker and advances timing. decreasing points gap causes the points to open later and retards timing . The other popular timing instruction says that the rotor tip should point opposite the number one contact in the distributor. This causes some to think that the rotor tip should point at the number 4 contact in the distributor cap and the timing ends up 180 degrees out of time . Neither timing instruction goes in to any real detail about rotational backlash in the distributor shaft and which direction that the backlash must be in when the points cam is tightened. Actually points gap isn't that great of a cause for the model A timing being that far off , as long as the gap is within Ford specs. The three most important things about model A timing is where the rotor tip points , direction of backlash after the points cam is tightened and that the upper plate has full swing within the window in the rear of the distributor cap. Full swing meaning that the lever on the breaker moves all the way to the right side of the window for retard and all the way to the left of the window in the cap for advance.

I don't set my timing by the points. When the timing pin drops in the dimple of the timing gear, I adjust the points cam so that the trailing tip of the rotor points at the number one contact in the distributor cap. When the cam screw is tightened , there must be no clockwise rotation in the distributor shaft. There is always some rotational backlash in the distributor shaft, sometimes as much as 1/2 inch . In other words, all rotational backlash must be in the counter clockwise direction , where it will have no effect on timing. The reason being is that when the engine runs, the distributor shaft turns in the counter clockwise direction . If clockwise backlash remains, the engine will have to turn to catch up the backlash before the distributor shaft can turn. When the engine must turn before the distributor shaft begins to turn , this causes the timing to be retarded to what ever amount of backlash that had to be caught up before the distributor shaft could turn. This is why direction of backlash is so important. If there is 1/2 inch of backlash in the clockwise direction after the cam screw is tightened, the timing will be so retarded that the engine probably will not even run. If it does run it will be very weak and the exhaust manifold will get red hot. As for points gap, I don't bother with retarding the spark lever. I turn the engine untill the rubbing block on the points is on the highest point on the cam lobe, I don't mess with the cam screw . I loosen the lock screw on the points block and turn the adjustable point untill the gap opens to .022 and tighten the lock screw on the points block. Twenty two thousants is maximum gap acording to Ford specs and advances the timing to the max before there is danger of starter kick back. For me this gives quickest throttle response and gives the most time before the rubbing block on the points wears to the point that the points will have to be readjusted. When the points gap closes to less than .018 it will be time to readjust the points or you will begin to lose power and the exhaust manifold will begin to over heat . Truth be known, the model A will run good as long as points gap is within Ford specs of .018 to .022. Some prefer a more conservative gap of .020. The highly respected method is when the timing is on the mark with the spark lever fully retarded that the points should be just ready to open. This can be correctly arrived at by points gap adjustment. I don't feel that it is worth the trouble and feel that it causes the confusion that ends up with the timing being off. There is only about .004 thousants leway in points adjustment within specs, that minor amount will change constantly as the engine runs and the points block wears . Cam lube will decrease wear and the length before points adjustments will be necessary. I don't believe that the small amount that the gap will fluctuate will be that noticable untill the gap closes to less than .018 .
Last edited by Purdy Swoft; 01-15-2015 at 12:52 PM.

Let's back up the bus a bit and reflect on a couple of things. This statement first: "I don't set my timing by the points." Since a spark occurs when the points just start to open, it follows that the points' position and gap is what determines timing, NOT the rotor tip. The position of the rotor tip has absolutely no effect on timing. Initial (or base) timing is set with the pin in the timing gear depression, timing lever fully up (this is critical), points gap set correctly and points just starting to open. Tighten the center screw, crank the engine exactly two turns to verify, then leave it alone for the life of the engine! Just keep the point gap set correctly, and the timing will never change until the timing gears and distributor gears are worn out.

Second point: We have been talking only about initial timing so far. As soon as the engine starts, the timing lever is pulled down a little, and the faster we drive, the further we pull the timing lever down (thus advancing the timing) to our favorite position.
So in reality, while driving the timing is never where we worked so hard to set it!
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Old 10-17-2019, 07:15 AM   #11
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Excuse me don't mean to hijack but can the points be changed without removing the distributor cam?
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Old 10-17-2019, 07:47 AM   #12
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Default Re: Timing

By "base" I meant that the timing advance/retard window in the distributor body being adjusted with the steering column being rotated. I know that works on 1930-31'models. What about any of the earlier models?? Late 29's??.

Quote:
Originally Posted by Jim/GA View Post
It works well, especially for a quick timing check or timing set by the side of the road.

You don't really need any "base" to use it.

Turn the engine over until the timing pin drops in the dimple, like normal timing procedure. Loosen the cam screw on top a little bit and use the wrench to turn the cam 1 or 2 times clockwise (to take slack out of the drive gears). Just as the wrench side begins to contact the 4th little pin on the top of the distributor body, you tighten up the cam screw. That's it!

You can leave the cam screw tight and put the wrench on the cam, then gently rotate it clockwise to check the timing any time you want.

The position of the timing lever is not important when using this wrench.

A very cool design.
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Old 10-17-2019, 09:44 AM   #13
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Default Re: Timing

Quote:
Originally Posted by History View Post
What do you guys think of the Nu-Rex timing wrench? I know you have to have a base to start with but it seems pretty simple to use.
That wrench only found by me to be approximate..Use Marco Tahtaras method or the Service Bulletins and a bulb (with 2 pigtails/alligator clips soldered to it) on the points arm to ground to check when points/close open after removing the lash as described. The rotor may not be exactly in the center of the #1 contact in the rotor and the rotor gap to body is important. For high compression heads, some A'ers suggest adjusting the spark plugs gap to .030-.032.
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Old 10-17-2019, 10:07 AM   #14
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Default Re: Timing

Quote:
Originally Posted by 40 Deluxe View Post
Let's back up the bus a bit and reflect on a couple of things. This statement first: "I don't set my timing by the points." Since a spark occurs when the points just start to open, it follows that the points' position and gap is what determines timing, NOT the rotor tip. The position of the rotor tip has absolutely no effect on timing. Initial (or base) timing is set with the pin in the timing gear depression, timing lever fully up (this is critical), points gap set correctly and points just starting to open. Tighten the center screw, crank the engine exactly two turns to verify, then leave it alone for the life of the engine! Just keep the point gap set correctly, and the timing will never change until the timing gears and distributor gears are worn out.

Second point: We have been talking only about initial timing so far. As soon as the engine starts, the timing lever is pulled down a little, and the faster we drive, the further we pull the timing lever down (thus advancing the timing) to our favorite position.
So in reality, while driving the timing is never where we worked so hard to set it!


I can see that you THINK that you are a real smart guy . Every time that I look back, you are attacking another one of my posts. If you want to continue to make your IGNORANCE obvious go right ahead

Its hard to believe that a person that CLAIMS to know Anything about timing would make the statement that rotor tip position has no effect on timing

Points gap determines when SPARK OCCURS.

If the rotor tip isn't set pretty damn close to the correct position the engine will be out of time and probably won't run

The MOST important thing about ignition timing is where the rotor tip points

Points gap and the exact moment that the spark occurs is secondary

Points gap can be way off and the engine will still run

A person with knowledge and experience with the model A will start the engine at full retard

The owners manual recommends full advance at speed

When driving the model A the driver controls advance and retard with the spark lever

If initial timing is off a person wont really know when hey are getting full retard or advance

Being as you are confused , INITIAL TIMING is MOST important

I've owned and timed model A's for nearly 60 years

Last edited by Purdy Swoft; 10-17-2019 at 10:27 AM.
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Old 10-17-2019, 10:47 AM   #15
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Default Re: Timing

Quote:
Originally Posted by Ray64 View Post
Excuse me don't mean to hijack but can the points be changed without removing the distributor cam?
Original style points require you to remove the distributor cam so that you can pop out the upper plate, to get to the wire connection and screws/nuts underneath the plate.

Modern style points do not require the upper plate be removed, so distributor cam can stay in place and you don't lose timing.
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Old 10-17-2019, 11:36 AM   #16
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Default Re: Timing

In such times that the upper plate must be removed to install original points

I mark the position of the rotor tip with close attention payed to backlash before loosening and removing the distributor cam

Marking rotor position is so much easier than going through the full timing process .
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Old 10-17-2019, 11:39 AM   #17
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Default Re: Timing

Quote:
Originally Posted by Tom in SW VA View Post
Can bad timing cause overheating in a Model A? Asking for a friend.
Yes!!

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Old 10-17-2019, 01:01 PM   #18
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Good pic .
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Old 10-17-2019, 03:39 PM   #19
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Thaanks for the info on changing the points RAY
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Old 10-18-2019, 11:44 AM   #20
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Default Re: Timing

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Yes!!

HOLLY MOLLY...I have never seen a manifold THAT hot before,looks to go all the way down to the muffler, that is pure insanity.
Seems great for manifold meals tho...
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