My untimeable motor.

[oldbee]

10BTDC is the line AT the 10. Where is your’0’ TDC mark on balancer? I see a bunch of lines in your picture. You need to mark the TDC line on balancer with chalk or white grease pencil.

 

[DynaBro]

It's a bright white line under that black line and piece of tape at the very bottom. I placed some tape there with another line at 2.36 inches counterclockwise from the TDC mark to attempt total timing.

 

[68-500]

If the white line is TDC. I believe your timing as is would be approximately 40* BTDC.

 

[kiwigtx]

It's a bright white line under that black line and piece of tape at the very bottom. I placed some tape there with another line at 2.36 inches counterclockwise from the TDC mark to attempt total timing.

I mean...there's only 360 degrees to choose from.....

 

[dvw]

If the idle speed is close to what it was set at the issue is inside the distributor. What this video for disassembly

Doug

 

[DynaBro]

View attachment 1913192

I mean...there's only 360 degrees to choose from.....

I did the math and verified it with Grok. At 3000RPM the 2.36 inches counterclockwise from the TDC mark should align with TDC.

 

[DynaBro]

If the idle speed is close to what it was set at the issue is inside the distributor. What this video for disassembly

Doug

Very informative.

 

[MoparLeo]

To verify TDC, Use the piston stop method and mark the Harmonic Balancer.
This will establish true TDC without removing the head and using a dial indicator.
Also check the Harmonic balancer for slippage between the inner and outer sections.
This will cause extreme swings in the timing marks.



AI Overview

To find Top Dead Center (TDC) with a piston stop, install the tool in the #1 spark plug hole, then rotate the engine by hand until the piston stops the tool, marking the harmonic balancer. Rotate the engine in the opposite direction until the piston stops the tool again, and mark the balancer. The true TDC is located exactly halfway between these two marks.


What You'll Need Piston stop tool (threads into spark plug hole), Socket wrench and spark plug socket, Marker or chalk, Harmonic balancer and timing pointer, and Hand or socket wrench to turn the crankshaft.

Steps to Find TDC

1. Disconnect the battery: and remove the spark plug from the #1 cylinder.
   
   
2. Thread the piston stop tool: into the spark plug hole until it's hand-tight.
   
   
3. Rotate the engine by hand, turning the crankshaft in the clockwise direction.
   
   
4. Watch the timing pointer: for the harmonic balancer.
   
   
5. Stop rotating: when the piston makes contact with the stop tool.
   
   
6. Make a mark: on the harmonic balancer where the timing pointer lines up.
   
   
7. Rotate the crankshaft in the opposite direction: (counter-clockwise).
   
   
8. Repeat steps 3-5: rotate until the piston makes contact with the stop tool on this side and make a second mark on the balancer.
   
   
9. Find the midpoint between the two marks: by measuring the distance and dividing it by two.
   
   
10. Rotate the crankshaft until the pointer aligns with the midpoint: you just calculated. This is your true Top Dead Center (TDC).

You can watch this video to see how to find Top Dead Center:

1m


Summit Racing
YouTube · Dec 19, 2013
Important Tips

• Never use the starter motor: to rotate the engine, as this can damage the piston.
  
  
• The piston will hit the stop tool twice per engine revolution (once on the exhaust stroke and once on the compression stroke). You're looking for the compression stroke mark.
  
  
• Once true TDC is found, permanently mark the balancer with a chisel or punch for future reference.