Pull the heads you might have a stuck valve or something on top of a piston

 

that could be it or



did you pull the belly pan and check the rotating assembly
a lot of times the valves could be stuck from non use, squirt some trans fluid in the sparkplug ports prior to pulling the heads or the pan
PB spray around the valves rotate what you can and let sit for a day or 2
drink beer and watch the motor
if this does'nt work then pull the heads some times a little corrosion will lock it
up 'moisture is the engines worst enemy':001_rolleyes:

 

Is the motor out of the car? On an engine stand? What are you using to rotate the crank? Pulling the valve covers and checking for a loose rocker is probably the easiest thing to do, but if you have a stuck valve caused by moisture, the engine needs to come apart for overhaul IMO. Jim.

 

it doesn't have any stuck valves, all are opening freely and effortlessly, the oil pan is off, im using a breaker bar on the balancer bolt to rotate it, engine is on engine stand. thanks mike

 

Also, how do you know all the valves are opening freely and effortlessly if you can only turn the engine 1/4 turn? It will take 2 full turns to be able to make that claim...

Greg

 

loosen up the main bearing caps, and see if it will turn, you may have a scarred bearing, I had this happen to me when I was 15 and building my first engine, damaged the bearing installing the rods

 

When it stops turning, does it stop abruptly, as if the impedement is something physical, or does it slowly bind up, like you are fighting compression, fighting against a binding bearing, etc? I would think if it was a bearing, you would start to feel resistance with your breaker bar, then it would become tighter as you turned, until it binds. If it was something more mechanical, like a stuck valve, you'd turn the breaker bar, then abruptly stop turning. Hard to describe what I mean.

Has the timing chain/gears been removed and reinstalled since the engine last spun freely? Perhaps they were not installed correctly, and your timing is all fouled up, causing interference.

Greg

 

What Greg said,plus have you looked at the bottom end?
Is there anything that might prevent the connecting rods from making a fee and unobstructed travel in a full turn?
I know some stroker engine need to have the cylinder bore bottoms notched for the additional stroke clearance,if it is not done the engine will bind in less than one turn.
Did the person you got the engine from put in a stroker crank and neglect to mention it?

Just a thought.
HTH
Paul

 

you dont need to turn the engine over to see if valves/lifters are stuck, its not a stroker motor it came out of a granada and is stock, pan is off and no visual problems in the rotating assembly, could a bearing bind up and cause it to act this way? thanks mike

 

yes it can loosen up the main caps and see if it rotates

 

Mike,is the timing cover off?Check to see if there's anything in the cam / crank sprocket that could be a problem.HTHPaul

 

many things can cause this. can you provide more info. What condidtion is the motor in. ie. is the flyweel installed, pulleys ect.

I would check

came gear bolt is incorrect or has a washer installed that should not be there

cam gear installed backwards and rubbing inside the timing cover

flywheel bolts to long

spun bearing on crank

give us as much info as you can and we should be able to resove this

stack

 

Betting something fell into the intake and is laying on top one of the pistons.

If you suspect valve being stuck. Remove the rocker arms.
motor turns over. Problem is valve train.

Motor does'nt turn over pull the heads and look for a tool,nut,bolt,ect.
This is not a bearing problem. This is caused by somethin in the combustion chamber hitting a piston

 

it was severe rust in the cylinders, especially the pistons at bottom of bore, looking for new motor now, thanks everyone

 

Boy that engine has seen better days!
Glad you found the problem.

Paul

 

Heck, fill the cylinders with penetrating oil, button it back up, fire it up and it'll run good as new.
And don't be concerned with all those clanking noises you might hear coming from the cylinders. It's just those stray metal fragments trying to find a way to exit the cylinder or crankcase. The noise will eventually go away!

Honest!

 

Wow that motor has not run in a long time. Looks like it's a very hi milage not very well maintained engine.
If you decide to rebuilt it. have that block checked well for possible cracks

 

you sure you dont want this in your cobra? :shifty: