MF 2135 w/Z134 once seized engine; now a hard stop precl

[rotorwing90]

1965 MF 2135 with Continental Z134 with Shuttle Shift transmission: A once seized engine now has a hard stop after a 5-10 degree rotation.

1. My shop manual has not arrived as of yet so I seek the wisdom of a kind/generous soul or two.
2. In the process of unseizing the engine, a hard stop was felt after I achieved a 5-10 degree engine rotation. I did not force it beyond the hard stop.
3. Ive removed the head to see the condition of the cylinders and to see if there was a foreign object in one of the cylinders. Cylinder walls were scaly but not too bad in my opinion (Scotch-Brite is being used to remove the scale). No foreign object found in cylinders.
4. My thoughts at this point: the hard stop is not from the bottom end (crank, main & rod bearings, journals) since the engine rotates its 5-10 degrees with minimal effort. Im thinking something connected to the cam shaft: camshaft lifters, oil pump, governor, distributor gear

In anybodys opinion, am I overlooking something?

Thoughts? Suggestions?

Dennis in the Texas Panhandle

 

[Bob N.Y.]

Do all of the pistons move up or down when you rotate the crank as far as it will go?

 

[rotorwing90]

Bob N.Y.-

1) Thanks for taking the time to reply. I really am grateful.

2) Yes, with the head off, I can observe all 4 pistons moving up and down, as far as the hard stop will allow.

Dennis from the Texas Panhandle

 

[rotorwing90]

Rotorwing90 said: With the head off, I can observe all 4 pistons moving up and down as cranks is rotated, until the 5-10 degrees and the hard stop is encountered.

This is why Im thinking the obstruction is not in the bottom end but in the camshaft assembly. And unless advised otherwise, Im in the process of gaining access to the timing chain cover as I write this.

 

[Phil Tibbetts]

Possibly a spun bearing on a rod

 

[rotorwing90]

So a spun bearing would allow some rotation but not a complete revolution?

But the problem could also be in the front end with the timing chain/governor assembly.

Im waiting for some input from those whove experienced a governor failure where the ball bearings come loose from their cage.

When I rotate the engine, the hard stop sounds and feels like its coming from the front of the engine.

Dennis

 

[Bob N.Y.]

Most tractor engines don't have timing chains, just gears. I suppose it is possible that a ball could have come out of the governor and wedged in between 2 teeth on a timing gear. Let us know what you find.

 

[rotorwing90]

I wish to do a follow up on my query on this thread: I was able to get the engine of my MF 2135 with the Continental Z134 engine to rotate. It is now rotating the full 360 degrees. The culprit? There was some corrosion in the top of the four cylinders that was acting as the hard stop. I dismissed it as not substantial enough. But I went ahead and removed it and viola! The engine now rotates.