The Ford Barn

Sodakmodela · 08-04-2015, 07:31 PM

I'm looking for the points gap and the best way to tune my model a up. What's ur ideas and strategies for getting one to run perfect? Thanks in advance!!

burner31 · 08-05-2015, 01:39 AM

Practice...practice...practice

point gap .020, plugs .035, beers 2

burner31 · 08-05-2015, 01:42 AM

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

marc hildebrant · 08-05-2015, 07:32 AM

I prefer to time per the owners manual or use Marco's method which is the best. Using a "picture" is a poor method and isn't exact.

Marc

katy · 08-05-2015, 10:31 AM

Quote:

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.

That's exactly what I was taught many years ago and it's still viable.

40 Deluxe · 08-05-2015, 01:29 PM

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All this fussin' about with the timing only sets initial, or base, timing! Once the engine starts and you pull the timing lever down, you have changed the timing. Changed it to what? The answer depends on far you pulled the lever down. The initial setting should be at TDC or slightly after to prevent kick back when starting, especially hand cranking. This is easily and quickly done using Ford's method, taking backlash into account, per Purdy's instructions. No need to get all OCD over a setting that that you change as soon as the engine starts and is changed repeatedly as you drive (uphill, downhill, fast, slow, etc.).

Patrick L. · 08-05-2015, 02:07 PM

I would suggest buying one of the repair manuals available at any of the 'A' vendors. The one by Les Andrews is very popular.

Willie Krash · 08-05-2015, 02:12 PM

Quote:

Originally Posted by 40 Deluxe

All this fussin' about with the timing only sets initial, or base, timing! Once the engine starts and you pull the timing lever down, you have changed the timing. Changed it to what? The answer depends on far you pulled the lever down. The initial setting should be at TDC or slightly after to prevent kick back when starting, especially hand cranking. This is easily and quickly done using Ford's method, taking backlash into account, per Purdy's instructions. No need to get all OCD over a setting that that you change as soon as the engine starts and is changed repeatedly as you drive (uphill, downhill, fast, slow, etc.).

Yep!
People get pretty anal over it.

Fred K-OR · 08-05-2015, 02:25 PM

Quote:

Originally Posted by burner31

Practice...practice...practice

point gap .020, plugs .035, beers 2

When I install a new set of points, I like to get the point gap at .020 or even .022. The reason I do this is I feel the point rub block on a new set of points will wear down faster that an old one so I want the setting to be within limits longer. Don't know if that make any sense but it is the way I do it.

marc hildebrant · 08-05-2015, 04:59 PM

With regard to comments about being "anal" or "fussing" too much, keep in mind that owning a Model A is about the pursuit of happiness and that concept is declared in the Declaration of Independence.

I like to set the timing "just right" and for me that is fun.

Marc

mrtexas · 08-05-2015, 05:09 PM

I put a file mark(white paint)on the crank pulley and timing cover at #1 TDC when indent on timing gear is lined up(I put a white mark on the indent as well). I determine TDC by putting my thumb over #1 spark plug hole to get to compression step and keep manually turning over until #1 piston is TDC. I use a mirror and flashlight to see indent mark as most marks aren't big enough to use the timing pin on. Then to test timing I turn on ignition and crank it over manually with #1 spark plug pulled to insure it is sparking at TDC using my mark. If it doesn't start after this something else is wrong as you have spark at TDC! Just happen to be timing 28 AR rpu today.

08-05-2015, 01:39 AM	#2
burner31 Senior Member Join Date: Dec 2014 Location: Shawnee, Ok Posts: 3,471	Re: Tuning up model a Practice...practice...practice point gap .020, plugs .035, beers 2 __________________ Keith Shawnee OK '31 SW 160-B

08-05-2015, 01:42 AM	#3
burner31 Senior Member Join Date: Dec 2014 Location: Shawnee, Ok Posts: 3,471	Re: Tuning up model a 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 __________________ Keith Shawnee OK '31 SW 160-B

08-05-2015, 07:32 AM	#4
marc hildebrant Senior Member Join Date: May 2010 Location: Cape Cod Posts: 1,128	Re: Tuning up model a I prefer to time per the owners manual or use Marco's method which is the best. Using a "picture" is a poor method and isn't exact. Marc

08-05-2015, 01:29 PM	#6
40 Deluxe Senior Member Join Date: May 2010 Location: now Kuna, Idaho Posts: 3,778	Re: Tuning up model a Sponsored Links (Register now to hide all advertisements) All this fussin' about with the timing only sets initial, or base, timing! Once the engine starts and you pull the timing lever down, you have changed the timing. Changed it to what? The answer depends on far you pulled the lever down. The initial setting should be at TDC or slightly after to prevent kick back when starting, especially hand cranking. This is easily and quickly done using Ford's method, taking backlash into account, per Purdy's instructions. No need to get all OCD over a setting that that you change as soon as the engine starts and is changed repeatedly as you drive (uphill, downhill, fast, slow, etc.).

08-05-2015, 02:07 PM	#7
Patrick L. Senior Member Join Date: May 2010 Location: Largo Florida Posts: 7,225	Re: Tuning up model a I would suggest buying one of the repair manuals available at any of the 'A' vendors. The one by Les Andrews is very popular.

08-04-2015, 07:31 PM	#1
Sodakmodela Junior Member Join Date: Aug 2015 Posts: 5	Tuning up model a I'm looking for the points gap and the best way to tune my model a up. What's ur ideas and strategies for getting one to run perfect? Thanks in advance!!

08-05-2015, 04:59 PM	#10
marc hildebrant Senior Member Join Date: May 2010 Location: Cape Cod Posts: 1,128	Re: Tuning up model a With regard to comments about being "anal" or "fussing" too much, keep in mind that owning a Model A is about the pursuit of happiness and that concept is declared in the Declaration of Independence. I like to set the timing "just right" and for me that is fun. Marc

08-05-2015, 05:09 PM	#11
mrtexas Senior Member Join Date: May 2010 Location: Sugar Land, TX Posts: 4,395	Re: Tuning up model a I put a file mark(white paint)on the crank pulley and timing cover at #1 TDC when indent on timing gear is lined up(I put a white mark on the indent as well). I determine TDC by putting my thumb over #1 spark plug hole to get to compression step and keep manually turning over until #1 piston is TDC. I use a mirror and flashlight to see indent mark as most marks aren't big enough to use the timing pin on. Then to test timing I turn on ignition and crank it over manually with #1 spark plug pulled to insure it is sparking at TDC using my mark. If it doesn't start after this something else is wrong as you have spark at TDC! Just happen to be timing 28 AR rpu today.