RootesRacer
If you do the rope trick right it will work everytime.First of all the piston has to be down or you can not even feed the line into the combustion chamber. Feed as much line as you can and then turn the motor with the crank bolt.The line will stop the piston.Now tighten your bolt,back up the engine and you are done.Simple one man job.Surely someone else who has turned a wrench has done this.I did not invent this method.It was taught to me somewhere done the line. I knew I would hear from the best of the best.I'm not telling anyone what to do.I'm just telling everyone I did it and it worked everytime.
I'm waiting for some reponse on the grease gun trick for freeing up frozen engines....I choose grease over gunpower.
With the grease trick the piston should be UP.That's all the geometry you need to Know.
Comments?.......
Respectfully yours,
Al Mason

Al,

You are not getting it.


The force on the rod is related to the vertical vector, which is dependant on the crank angle of the rod when the piston locks.

Even with the crank throws at 90 degrees, your 100 lb/ft of torque is greater at the piston since the rods are NOT infinitely long. As the rod to piston angle (theta) approaches zero degrees, the force approaches infinity (tangent of theta).

To Rootes Racer,
I get it now-You got an A in geometry but cannot understand the clothesline because it's not in the book.I'm impressed how you said so much and at the same time said nothing.
You obviviously are no dummy like me so why not put your high intellect to work and think about a clothes line filling up a spark plug hole instead of trying to baffle us by over-explaining the guts of an engine..The rope trick does WORK even if it is too simple for some to comprehend.
Oh well I guess I'll never get it.....
Thank you very much,
Agm
ps
Has anyone ever lit a fire on top of a cold frozen flooded Alpine carb? I have.It gives new definition to 'fire in the hole' and will fire up any cold engine and is more impressive than the rope trick......
I want to thank Chuck in Canada for the kind words.We are not related.
Thanks Chuck!!Now thats funny!!!!

Al,

I quit the argument becuase you aren't getting it, and my time is more valuable than your rod bearings.

You want an explanation, here it is.

The force on the rods pins and bearings is proportional to the vector of the crank angle due to its leverage as acted on by the crank. This is easy, perhaps even you got this.

The force on said components exponentially increases as the piston gets nearer TDC.

The rod bearings are what takes that force when the piston begins to lock.

The ugly part is that as the force is rising while the crank is still rotating (due to the spring rate of the compressing rope), makes a nice dent in the white metal on the bottom shell.

Someone caclulated (I'll trust the math) that the force was 1140 lbs with the crank at 60 degrees and 100 lbs ft of torque aplied to the crank snout.

No I ask you, can you imagine the effect on the softmetal bearings with that amount of load on them, while rotating that last couple of degrees, all without the benefit of the hydrodynamic lubrication the engine sees when it has oil pressure?

Now imagine what the force and consequent damage of the shells will be with the clothesline inserted where you didnt pack the cylinder half full of rope before it locked up (where the crank angle was less than 60 degrees).

I myself have had many engines apart, Ive seen what happens to bearings when the motor is locked and you try to turn it anyway (like if a timing belt breaks, or if the cyls have oil/water or fuel loaded in them).

Anyhow Al, this is all probably wasted on you. I never said that your procedure wouldnt tighten down the crank bolt, what I said was that it was stupid and you will damage your rods and bearings.

Why on earth you would want to damage your bearings for lack of an impact wrench just blows my mind.

Was that saying enough this time sir?