Locating dimple on timing gear

[Y-Blockhead]

Originally Posted by aermotor

When you do find it borrow some of the wives nail polish and dab some in the dimple. Makes it a lot easier to find with a mirror and flashlight next time.

John

I just fabbed an external pointer and marked the pulley. Much easier than dealing with the pin.

[erdaviesjr]

So, if I had set my timing to what I thought was TDC, but in reality it was the top of the exhaust stroke on #1 piston, how would that play out when I tried to start the engine or run the car? I assume it would not start easily, run very well, and would backfire like crazy?? or not run at all??

[J Franklin]

Originally Posted by erdaviesjr

So, if I had set my timing to what I thought was TDC, but in reality it was the top of the exhaust stroke on #1 piston, how would that play out when I tried to start the engine or run the car? I assume it would not start easily, run very well, and would backfire like crazy?? or not run at all??

You are correct. I use my thumb over the plug hole to know when it is coming up to TDC.

[bigd1101]

Originally Posted by erdaviesjr

So, if I had set my timing to what I thought was TDC, but in reality it was the top of the exhaust stroke on #1 piston, how would that play out when I tried to start the engine or run the car? I assume it would not start easily, run very well, and would backfire like crazy?? or not run at all??

This is why the dimple is used to set the timing. It's really not that complicated although with so many cooks in this broth here, and we all have our own methods in dealing with our cars, the easiest way (logically speaking) is once again, remove the spark plugs, put the car in NEUTRAL, and turn the engine over by hand using the fan or belt until you find the allusive dimple. Do NOT attempt this with the car in 3rd gear......as you are setting up a broken fan, a broken fan pulley and you are fighting against the gear you are in. The engine will turn very easily in NEUTRAL with the plugs OUT. This method makes it easy as you can turn the engine over as many times as it takes to find the indent, which on some cars, can be very difficult depending on the depth of the dimple.


Don

[donald1950]

i just spent about 2 hours turning the motor over very slowly with the fan belt and watching the rotor approach #1 position and i finally hit it and then use the fan belt to rock it back an forth to verify. it sure dont move much.......

[30 Closed Cab PU]

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Originally Posted by donald1950

i just spent about 2 hours turning the motor over very slowly with the fan belt and watching the rotor approach #1 position and i finally hit it and then use the fan belt to rock it back an forth to verify. it sure dont move much.......

I believe one or two of the venders sell a timing pin that is spring loaded so you do not have to hold the pin while turning the motor - maybe that would help.


Do not remember why, at one time was told not to use the fan belt to turn the motor, maybe hard on the water pump and generator bearings?


Also maybe something about the belt being tensioned to tight if able to turn the motor with the fan belt?


Interested in what other say about this.

[Y-Blockhead]

I bent up a 1⅜" wrench to fit the ratchet nut for turning over the engine slowly. The vendors sell a similar wrench. Just don't forget to remove it before you start the engine...

[katy]

I use my thumb over the plug hole to know when it is coming up to TDC.

Good logic.

[37 Coupe]

Originally Posted by alexiskai

If your camshaft gear is placing the dimple under the timing pin hole at the top of the exhaust stroke, the gear has been installed wrong. The camshaft gear rotates at half the engine speed, so the dimple will only come around to the correct position on the compression stroke.... that's the whole point.

Except in the case of a timing that was on my Model A engine,the dimple was drilled off a tooth.Not a new one but not the original one either.It had a metal hub that was loose and I went to replace it with one from Brattons so I thoughtBrattons was the wrong one until I checked with a couple other original ones. I remember than that the son of the previous owner told me this Model A starts and runs different than others concerning spark advance rod.

[Purdy Swoft]

The real problem is that the timing dimple on all of the replacement cam gears are to small for the original timing pin to work well. It is always best to enlarge the dimple when replacing the timing gear . I use a five sixteenths drill bit to enlarge the dimple . If the dimple is large as original , the model A is probably the easiest car ever to set the timing on . Since I was fourteen years old I've never needed to stick anything in a spark plug hole to tell when the piston was at the top or use a mirror to see the dimple through the timing pin hole . Ford made the model A simple for the common man to set the timing . A lot of people try to make setting the timing as difficult as possible and usually end up with a car that won't run at all .

[BillLee/Chandler, TX]

Originally Posted by Purdy Swoft

The real problem is that the timing dimple on all of the replacement cam gears are to small for the original timing pin to work well. It is always best to enlarge the dimple when replacing the timing gear . I use a five sixteenths drill bit to enlarge the dimple . If the dimple is large as original , the model A is probably the easiest car ever to set the timing on . Since I was fourteen years old I've never needed to stick anything in a spark plug hole to tell when the piston was at the top or use a mirror to see the dimple through the timing pin hole . Ford made the model A simple for the common man to set the timing . A lot of people try to make setting the timing as difficult as possible and usually end up with a car that won't run at all .

+1!!!!


Sharpening the end of the timing pin a bit helps as well if you can't get to the dimple to drill it larger.

[Purdy Swoft]

I agree .

[100IH]

Have seen compression tester hose with a whistle in place of pressure gauge, You know how to whistle don't you. Handy if it takes 2 hands to turn the crank. Also, If the side cover happens to be off, the #1 lifters will be equally down - both valves closed AND #4 lifters will be equally up - both valves open part way. that is where compression ends and power starts TDC will be within 2-3 deg. one way or another. Don't use a dog whistle, you won't hear it.

[Will N]

I find it amazing all the trouble folks have with just using the stock timing pin as designed with just the engine crank to turn the engine over. Maybe I'm lucky in that my timing dimple is pronounced enough that I can locate TDC with no problem. Remove the distributor cap and crank it around until the rotor comes close to the #1 terminal. Remove the pin and insert and while standing between the bumper and radiator, with your left hand put pressure on the pin. With your right hand (and maybe with help from your right knee!) slowly crank it over and you will feel the pin move as it drops into the dimple. It's as simple as can be- no need for mirrors or timing marks or spring loaded doodads- just as Henry intended.

[alexiskai]

Originally Posted by Will N

I find it amazing all the trouble folks have with just using the stock timing pin as designed with just the engine crank to turn the engine over. Maybe I'm lucky in that my timing dimple is pronounced enough that I can locate TDC with no problem. Remove the distributor cap and crank it around until the rotor comes close to the #1 terminal. Remove the pin and insert and while standing between the bumper and radiator, with your left hand put pressure on the pin. With your right hand (and maybe with help from your right knee!) slowly crank it over and you will feel the pin move as it drops into the dimple. It's as simple as can be- no need for mirrors or timing marks or spring loaded doodads- just as Henry intended.

I think the main problem that people are inventing fixes for is the scenario where the rotor isn't already in roughly the right spot. A lot of distributor projects require removing the rotor and cam, or maybe the distributor was removed and then the engine position shifted while it was off.

In these cases, the need to potentially crank the engine through an entire cycle while feeling for the dimple is tedious and frequently strenuous. I often overshoot the dimple when doing this and have to back up or crank around again. So it doesn't surprise me that various workarounds have emerged as everyone makes up expedient solutions to a common problem.

[Patrick L.]

I don't understand why this seems to be a common problem and probably never will.

[30 Closed Cab PU]

I had problems 1st time, then found the tip about lining the rotor up with the #1 contact, still was not easy until I found it. Was looking for more of a depression and was tuning the crank too fast. Once I did it once or twice, then it was easy.

[Patrick L.]

Yep, practice makes perfect.

[Jacksonlll]

I know it is easy to turn the engine over using the fan blade, but I think it is the wrong thing to do. The pulley was designed to drive the pump and generator, not the engine. If you break your pulley, you have a bigger problem.
If you damage the fan blade, that is a major safety problem. I always just rock the car in third gear. Just my opinion.

[J Franklin]

Originally Posted by Jacksonlll

I know it is easy to turn the engine over using the fan blade, but I think it is the wrong thing to do. The pulley was designed to drive the pump and generator, not the engine. If you break your pulley, you have a bigger problem.
If you damage the fan blade, that is a major safety problem. I always just rock the car in third gear. Just my opinion.

That is what I think also. It is very easy to turn the engine with the crank when the plugs are out.