Recently picked up a 1970 f250 that had been in a field sence 1998 and sure enough the engine is rust seized. I did the typical and pulled all the plugs and oiled the cylinders and also pulled the valve covers and oiled everything. Tried to turn the motor again and this time i managed to break it free a few days later. Only problem is that it only turns 1/4 revolution back and forth freely and suddenly stops both ways. Any idea what may cause this on a 360fe? Do i still have rust problems or preexisting problems?

 

You don't want to force it to turn because some valves may be hanging up. With the valve covers removed you should be able to see which ones don't move.

 

Thanks for the info, i checked the valves and a few start to move as i rotate the engine but the springs are so strong i cant even move the valves by hand that move when the cam turns so i will pull the rocker shafts and see if it turns over then.

 

the reason why you can only turn the engine over 1/4 a revolution is because the cylinder walls are rusted to and the only way to free it up is to pull the heads and re hone the cylinders the rings are hitting the part of cylinders that have rust on the walls.

 

A 50/50 mix of auto tranny fluid and acetone has been scientifically shown to be +50% more effective at breaking rust loose than the leading commercially available formula.

To hone the cylinders... the pistons must first be removed... so theres that.


Less than a month ago I broke a '02 7.3 block free after it had been sitting outside with the heads off for 6 months... with less than a quart of fresh super tech wall mart trash atf...

Let it sit in the cylinders for about 10-15 minutes and put a socket on the damper bolt.
Gently rocked it back and forth and it was spinning in no time.

 

Looks like that 7.3 may have been rooted to the ground

 

Pretty close Brother

Its in a much more appropriate condition to give it the respect it deserves at this juncture.

It has been dubbed "Zombieheart".
There is a thread on one of the first few pages of the 99-03 7.3 section on FTE titled:

" Resurrection - rebuilding an engine with cylinder damage. - Ford Truck Enthusiasts Forums "

But here are some nice engine **** pics for the non clickie types...


The cause of all the trouble... (among another very controversial cause)


Phosphate treated crankshaft-flywheel adapter/spacer. Probably the only one on Earth like it!


After 260 some odd thousand miles of raw unfettered abuse...
This is the most pronounced wear on a journal set on the crank.
It measured less than .001"
So split in half it was less than .0005" wear per side. Which should hold tolerance after a polish job on stock mains and rod bearings. (The size fellas... not the factory original stock bearings I just took out... sheeeesh!)

Just about ready to go visit the block surgeon...

And yes I do realize the irony of the block being outsourced for cam/crank polish and cylinder boring while there is a fully tooled cnc machine shop in the background in most of these pictures.. i would just rather pay someone who does that specifically for a living than build an angle plate for my bridgeport. It is an entire pain in the excretion point...

My blossoming paint application skills on display.

This thing is truly going to be an attention "Grabber"

And finally... it meets some new friends in the waiting room at the Blockhospital...