Distributor advance problem

J

jack wingard

Senior Member
Removed my distributor to torque the head and did a carb rebuild. All back together. It runs nice and smooth except I have no distributor advance, the plate moves as it should but there is no effect when moving the lever. Am i missing something?
 
Just to make sure I understand, you're saying you've verified the linkage between the upper plate and the spark advance rod, and the upper plate pivots correctly, but when the engine is on and you adjust the lever on the steering wheel, there's no discernible effect on the RPMs or anything else?
 
alexiskai said:
Just to make sure I understand, you're saying you've verified the linkage between the upper plate and the spark advance rod, and the upper plate pivots correctly, but when the engine is on and you adjust the lever on the steering wheel, there's no discernible effect on the RPMs or anything else?
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Yes that's what I'm saying, it don't make no sense to me
 
Have you unhooked the upper plate from the rod and moved the plate with your finger while the engine is running (don't get shocked), and see if it works then. Something has to not be moving somehow.
 
Do you have a regular points and condenser setup? Or do you have electronic or automatic advance system?
 
Figured it out. Pretty simple. Old carburetor had to be set at high idle. Now rebuilt I have low rpm idle. Advance now works after rpms are higher.
 
If the upper plate is moving and the points are attached to that plate you should hear a difference in the sound when you retard the spark. I agree something is not right.
 
Points gap effects timing because the spark occurs when the points begin to open .Ford recommended a gap , anywhere from eighteen to twenty two thousands . Your points gap is too wide and has an advancing effect on timing . I would reduce the points gap to twenty thousands and see if it makes a difference . The MOST important thing about ignition timing is where the rotor tip points when the timing pin drops into the mark on the cam timing gear . With the timing pin in place , loosen the screw on the rotor cam and adjust to where the trailing edge of the rotor tip points exactly at the number one spark plug electrode in the distributor cap with NO CLOCKWISE backlash . Some have as much as one half inch of backlash in the distributor shaft . In many cases , clockwise backlash in the distributor shaft will cause the timing to be retarded . The distribuyor shaft rides on the counter clockwise side of the backlash . In other words if the direction of backlash causes the engine to have to turn to catch up the backlash before the distributor shaft begins to turn , the timing will be retarded to the amount of backlash that remains in the shaft . When the teeth on the oil pump and distributor shaft gear wears it causes backlash . In such cases the backlash will give free rotational movement in the distributor drive shaft . The backlash must not be allowed to remain on the side of the shaft gear that the gear rides on .
 
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I'll change the point gap. I'm also going to use Les Andrews method with the light. I also realized I was turning the crankshaft the wrong way to drop the pin in the dimple to find top dead center. I'm sure that makes a difference with the backlash. I'll try all this early next week let you know my findings. Thanks for everyone's help so far since I'm just a newbie of being a Model A owner
 
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There is very little backlash in the cam to crankshaft gear mating. Rotating the crankshaft either way to allow the pin to fit in the recess of the cam gear is acceptable.
 
John said:
Rotating the crankshaft either way to allow the pin to fit in the recess of the cam gear is acceptable.
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You state that, but I have never read that it would be the way to time a Model A Ford. And there are aggregate clearances that must be rotationally mitigated for precise timing and a great running powerful engine. Do it by the Ford book.
 
The model A is the easiest engine to time that I know of , when the pin method is used . I recommend first removing all of the spark plugs to remove compression and resistance . If compression isn't first removed , the closer you get to the timing mark , the harder the engine will get to turn and often cause a person to pass the timing dimple .
 
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