Flywheel Question

NCmau

Member
I am at the point of reinstalling the flywheel. Maybe I do not understand all I know here, but something is not making sense. The engine is still out but the oil pan is mounted while the engine head is on temporarily and it can be easily removed . Both No. 1 valves are closed. If I would install the flywheel the 4 deg mark would be a 4 oclock while the inspection hole is at 1 oclock. Is this wrong or am I missing something?
I was careful about not changing the positioning of the crankshaft and the camshaft. I did remove and reinstall the crank couple of times, but I always tried to put it back in the same position. At least I think I did.
I did not open the timing gear case to check the marks (yet). This tractor ran good before the oil pickup tube fell off.
I can use some words of wisdom here.
 
"I did not open the timing gear case to check the marks (yet)." I see that as the next step.
 

When I removed the crank, the timing gears did not move and when the crank was reinstalled, I made sure that it was placed in the same position that I marked. I have no idea why it is off. I hate to take the timing gears cover off but I will if I have to.
 
(quoted from post at 09:16:40 07/17/18)
When I removed the crank, the timing gears did not move and when the crank was reinstalled, I made sure that it was placed in the same position that I marked. I have no idea why it is off. I hate to take the timing gears cover off but I will if I have to.
more precise method of identifying number one TDC-compression stroke is what Hobo calls "on the rock".. With number 1 at TDC-compression, observe the valves at #4 cylinder & as you rotate the crankshaft ever so slightly CW & then CCW, back and forth, the intake and exhaust on #4 will both be slightly open and as you rock back & forth CW/CCW, the two valves will alternately move to open & closed from their equally & slightly open position (intake/exhaust overlap). TDC will be at he center of this movement of the valves, where neither is moving. Even the slightest rotation in either direction from TDC will result in valve movement.
 
(quoted from post at 14:48:35 07/16/18) I am at the point of reinstalling the flywheel. Maybe I do not understand all I know here, but something is not making sense. The engine is still out but the oil pan is mounted while the engine head is on temporarily and it can be easily removed . Both No. 1 valves are closed. If I would install the flywheel the 4 deg mark would be a 4 oclock while the inspection hole is at 1 oclock. Is this wrong or am I missing something?
I was careful about not changing the positioning of the crankshaft and the camshaft. I did remove and reinstall the crank couple of times, but I always tried to put it back in the same position. At least I think I did.
I did not open the timing gear case to check the marks (yet). This tractor ran good before the oil pickup tube fell off.
I can use some words of wisdom here.

Will the flywheel mount in more than one position? remember there are two sets of timing marks on the flywheel.
 
(quoted from post at 10:36:05 07/17/18)
(quoted from post at 14:48:35 07/16/18) I am at the point of reinstalling the flywheel. Maybe I do not understand all I know here, but something is not making sense. The engine is still out but the oil pan is mounted while the engine head is on temporarily and it can be easily removed . Both No. 1 valves are closed. If I would install the flywheel the 4 deg mark would be a 4 oclock while the inspection hole is at 1 oclock. Is this wrong or am I missing something?
I was careful about not changing the positioning of the crankshaft and the camshaft. I did remove and reinstall the crank couple of times, but I always tried to put it back in the same position. At least I think I did.
I did not open the timing gear case to check the marks (yet). This tractor ran good before the oil pickup tube fell off.
I can use some words of wisdom here.

Will the flywheel mount in more than one position? remember there are two sets of timing marks on the flywheel.
he dowels allow flywheel to fit two different ways and with two sets of timing marks, either way is correct.
 
That is what I was thinking, it has been a few years since I last did one and I did not remember worrying about the timing marks.
 
(quoted from post at 11:08:33 07/17/18) That is what I was thinking, it has been a few years since I last did one and I did not remember worrying about the timing marks.
ithout dowels, he would have other possibilities...........not good ones.
 
(quoted from post at 15:06:50 07/17/18)
(quoted from post at 09:16:40 07/17/18)
When I removed the crank, the timing gears did not move and when the crank was reinstalled, I made sure that it was placed in the same position that I marked. I have no idea why it is off. I hate to take the timing gears cover off but I will if I have to.
more precise method of identifying number one TDC-compression stroke is what Hobo calls "on the rock".. With number 1 at TDC-compression, observe the valves at #4 cylinder & as you rotate the crankshaft ever so slightly CW & then CCW, back and forth, the intake and exhaust on #4 will both be slightly open and as you rock back & forth CW/CCW, the two valves will alternately move to open & closed from their equally & slightly open position (intake/exhaust overlap). TDC will be at he center of this movement of the valves, where neither is
moving. Even the slightest rotation in either direction from TDC will result in valve movement.

I think I got Hobos “on the rock” TDC. No.1 and 4 piston are equal distance from the top. I suppose at this point the timing marks of the cam gears should be matching. I did not go in there yet but I guess I have to. If the marks are where they supposed to be, then I imagine the crank has to be repositioned to match the flywheel position.
Yes the flywheel has two opposed sets of markings but it does not really matter. As stated, the dowels dictates the exact flywheel position.
All I am concerned at the moment that I want to get this timing thing right while the engine is out. If I have to get the bottom open again and reposition the the crank, so be it!…but I do not have to like it.
mvphoto19937.jpg
 
(quoted from post at 15:48:51 07/17/18)
(quoted from post at 15:06:50 07/17/18)
(quoted from post at 09:16:40 07/17/18)
When I removed the crank, the timing gears did not move and when the crank was reinstalled, I made sure that it was placed in the same position that I marked. I have no idea why it is off. I hate to take the timing gears cover off but I will if I have to.
more precise method of identifying number one TDC-compression stroke is what Hobo calls "on the rock".. With number 1 at TDC-compression, observe the valves at #4 cylinder & as you rotate the crankshaft ever so slightly CW & then CCW, back and forth, the intake and exhaust on #4 will both be slightly open and as you rock back & forth CW/CCW, the two valves will alternately move to open & closed from their equally & slightly open position (intake/exhaust overlap). TDC will be at he center of this movement of the valves, where neither is
moving. Even the slightest rotation in either direction from TDC will result in valve movement.

I think I got Hobos “on the rock” TDC. No.1 and 4 piston are equal distance from the top. I suppose at this point the timing marks of the cam gears should be matching. I did not go in there yet but I guess I have to. If the marks are where they supposed to be, then I imagine the crank has to be repositioned to match the flywheel position.
Yes the flywheel has two opposed sets of markings but it does not really matter. As stated, the dowels dictates the exact flywheel position.
All I am concerned at the moment that I want to get this timing thing right while the engine is out. If I have to get the bottom open again and reposition the the crank, so be it!…but I do not have to like it.
mvphoto19937.jpg
I think I got Hobos “on the rock” TDC. No.1 and 4 piston are equal distance from the top. "
"Equal distance is not right, unless they can't go any higher in the bore.....and I'm confident that they can. So, it looks like you have to remove timing cover. When you align the marks on cam gear & crank gear, expect the pistons to all be at mid cylinder.
 


Well I did open the timing cover and I did have hell of a time. I could not figured out at first why it would not come out. I did not want to force that fragile cover. I finally realized that the culprit was the one piece front seal that I installed thinking was a good thing. Maybe it is if you do not have remove the timing cover. So I ended up removing the oil pan which I would have to do anyway because the timing marks [b:3568e8b45f]did not align[/b:3568e8b45f].
So tomorrow I will reinstall the crank with the respective timing marks. I guess I screwup when I reinstalled the cranks. In retrospect, I should have had the timing cover off. Lesson learned!!
 

Timing marks are matched and flywheel marks are now visible in the inspection hole. According to the IT manual, at the beginning of the compression stroke of no.1, flywheel mark 16-18 deg, I would place the distributor in the hole, pointing the No. 1 cylinder and go from there with the final adjustment when the engine is running.
If this is the right approach, then I should move with the installation of the clutch and button up the engine…..I hope!
 
pointing to the No. 1 cylinder [u:4253558a53]position in distributor cap[/u:4253558a53] and .........
It will turn a little when you insert it due to gear teeth design, so you may need to try a couple of different positions.

You made it sound like timing gear marks are matched when flywheel marks are visible in hole. (not simultaneous events) You likely meant that gear marks were matched and then crankshaft rotated until #1 TDC-C is approaching and stopped at 16 deg.
 
flywheel mark 16-18 deg

When setting initial position of distributor (static timing) it is customary to have cylinder #1 at 0° on compression stroke (both valves closed).

Depending on how you set the distributor drive gears, #1 can be any one of the 4 towers in the distributor cap. When it left the factory, the rotor was pointing toward the right, front cylinder head bolt to fire #1 cylinder. The insulated stud on distributor housing was at 8 O'clock and the number 1 nipple on the distributor cap was at the 10 O'clock position.

Also, the firing order is 1-2-4-3 and the distributor rotates counterclockwise.
 


I can not get both valves on #1 closed at 0 deg.

Here is what I got.

#1 piston: At 0 deg intake open, piston at 3-5/8” down
#4 piston: At 0 deg Exhaust open

#1 piston: Past 20 deg, both valves are closed, piston 3-1/2” down.
#4 piston: Exhaust open

#1 piston: At 16 deg, intake barely open, piston at 3-5/8” down (bottom)
#4 piston: Exhaust open, piston 3-5/8” down

Should I drop the distributor at 16 deg like book says, or should I drop it at 0 deg? I understand the position of the rotor and the advance setup. I guess I can always do the final adjustment after the engine is in place. I just want to make sure I am ok with the current basic setup before the engine is bolted.
 
(quoted from post at 13:09:17 07/21/18)

I can not get both valves on #1 closed at 0 deg.

Here is what I got.

#1 piston: At 0 deg intake open, piston at 3-5/8” down
#4 piston: At 0 deg Exhaust open

#1 piston: Past 20 deg, both valves are closed, piston 3-1/2” down.
#4 piston: Exhaust open

#1 piston: At 16 deg, intake barely open, piston at 3-5/8” down (bottom)
#4 piston: Exhaust open, piston 3-5/8” down

Should I drop the distributor at 16 deg like book says, or should I drop it at 0 deg? I understand the position of the rotor and the advance setup. I guess I can always do the final adjustment after the engine is in place. I just want to make sure I am ok with the current basic setup before the engine is bolted.
Have you looked at the other sets of marks?
 

I do not see how it would make any difference. They are 180 deg out, and by switching the position of the two dowel pins nothing is changed. I believe the the two sets of markings, and correct me if I am wrong, are there to change the rest position of the starter gear. Like I said, I am just guessing.
 
The difference is with one set of timing marks 0 aligned with pointer both #1 and #4 pistons will be at the top of their stroke. With the other set of timing marks 0 aligned with the pointer, both #1 and #4 pistons will be at the bottom of their stroke. You want to use the marks that have the pistons at the top.
 

Thanks for joining in. I think I am getting too educated here. So right now I have the 0 mark at the bottom of the stroke. I reinstalled the flywheel just like it was before. So how is it important to have the 0 mark at the top of the stroke? I am just trying to understand this so that I can relate to the IT manual instructions… as inserting the distributor at the 16-18 deg mark.
 
(quoted from post at 18:43:37 07/21/18)
Thanks for joining in. I think I am getting too educated here. So right now I have the 0 mark at the bottom of the stroke. I reinstalled the flywheel just like it was before. So how is it important to have the 0 mark at the top of the stroke? I am just trying to understand this so that I can relate to the IT manual instructions… as inserting the distributor at the 16-18 deg mark.

I would go back and reread your FO-4.use the marks that show up when number 1 cylinder is on compression stroke. Should be at the 0 mark when number 1 is at TDC and install the distributor at 4 Degrees. the 16 18 marks are used at 2000 rpms
 
(quoted from post at 16:01:17 07/21/18)
I do not see how it would make any difference. They are 180 deg out, and by switching the position of the two dowel pins nothing is changed. I believe the the two sets of markings, and correct me if I am wrong, are there to change the rest position of the starter gear. Like I said, I am just guessing.

The second set of marks is there so you can use a timing light from any spark plug. for installing the distributor, use the set that shows up when #1 is on compression stroke. It is all in the FO-4
 

Geiger, thanks for clarifying my cloudy understanding. I did not know the reason of the second set of marks. I changed the flywheel position and, sure thing, the 0 mark was right on the compression stroke where it should be. Again, I appreciate the help (and everyone else) and now I can move forward.
 
(quoted from post at 08:01:17 07/22/18)
Geiger, thanks for clarifying my cloudy understanding. I did not know the reason of the second set of marks. I changed the flywheel position and, sure thing, the 0 mark was right on the compression stroke where it should be. Again, I appreciate the help (and everyone else) and now I can move forward.

Glad you got it figured out, it is a common mistake, I made it the first time I did one. thanks for the feedback.
 

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