my son and I just got his 460 back from the machine shop, and we assembled it with the torque specs and sequences. But the motor is a bear to turn over even with a breaker bar. we disconnected the tranny and converter, took off the fly wheel, and still is the same. it feels like something is grinding. Also when we first tried to turn the motor over (with a gear reducted starter) it turned over real slow. yes the battery was new a red to optima. the motor is .040 over, dish pistons, heads cut down for roller rockers, hv oil pump, lunati 600 lift cam, and an eldebrock gear drive. the only thing that is changed is the block. the other block had a crack between oil pump shaft and second main bearing. the new block is a 460 interceptor block. please help if you can. this motor is for my sons 1972 gt qcode torino any help is appreciated than you

 

Take off the oil pan and while someone turns the engine over (safely), see what is happening.

 

not trying to sound dumb, but what am i going to be looking for.

 

See if everything is rotating correctly or if something is getting in a bind.

 

will do that tommorrow, what do you know about cranckshafts? like if they fall over asnd are not picked up for awhile can they warp. the reason i ask is the machine shop that did our worked had left our crank laying on the ground after being nocked over for awhile like weeks. the crank had allready been balanced from the first build 13 years ago.

 

Shouldn't really had hurt it...but would been nice for them to recheck it since it was their mistake.

 

I'm not saying you did this but some people don't install the correct crank bearings. Did you free spin the crank before you mounted and torqued the bearing cap down?

After adding the pre-lube and then bearing caps I've always made it a habit to turn the crank as I'm going through the torque sequence.

 

I assume the block was line bored ? If so the main caps should have been installed after the block was cleaned and torqued down to spec after the line boring WITHOUT the crankshaft installed and measurments checked and recorded. Then you Mic all the crankshaft journals and record the measurments. Compare each crankshaft journal measurment to the correct block main measurment. This will give you a starting point for which bearings you will use (like if you can use regular size, oversized...etc..). Assuming all measurments work out and the right bearings are installed for proper clearance (with assembly or break in lube on crank and bearing surfaces) try untorquing each main cap one at a time while rotating the crankshaft, when the crank begins to spin with ease, you know you've found the main that's causing it to bind (whether it's caused by the crank, main bearing clearance or what is up to you to find out). Usually once all the measurments are taken and compared to the bearings that are installed for clearance, the problem is obvious...most of the time...this is just a very short way to try and trouble shoot this issue, building an engine with proper clearances is a little more involved and if not done properly will result in your engine being used for a boat anchor instead of an engine......hope this helps.

 

Sounds like something is in a bind. Also you may have to pull the heads to make sure the valves aren't hitting the pistons

 

Moved to correct forum.

 

I hate to say this, but if it's turning over that hard and sounds like something is "grinding" you've probably already destroyed whatever parts that are causing it to turn that hard and will probably have to replace those parts....

 

thanks for the help on motor, pulled a blonde. we had the heads cut down for roller rockers and we over adjusted the valves. found one slightly bent pushrod. everything else is ok. thanks agian for the help. now we are putting a painless wiring harness in and i need a schemtic for the ignition, and turn signal switches, if any one has these please let me know. hopefully be able to finish by wednesday with wiring and reinstall of motor. if we can do this will put video of car on website.