I'm rebuilding the 302 out of my '80 F-150. I'm using the original crank & the bearing gap is a nice .002 (by the plastigage). Everything was going fine until I went to put the pistons in. The crank will NOT turn over when torqued to specs. By playing with it, I found that it will turn at 45 lbs instead of the normal 60-70 lbs. Has anyone ever had this happen to them? Of so, what did you do to solve the problem.

 

Did you make sure to put the main caps back in the order they came off??

 

Yes. The only problem I'm having is with the rear cap. If I loosen it up, everything's fine, even with the rest torqued to 70 lbs.

 

Been doing some more research on this. I've found some torque spec references online that say 60-70 ft/lbs for the main cap bolts and 35-40 ft/lbs for outer main cap bolts. My chilton's doesn't list outer cap bolts. Are they referring to the front & rear caps? To my knowledge, there's never been a normal 302 with a 4-bolt main (Boss don't count). Thinking maybe if that's the case, I was over-torquing them. Or am I just totally lost here?

 

I have never use a different torque on the outer mains...

are the caps from that motor?
did you try and swap the bearings around, might be a bad bearing..

you said after you tried to put the pistons in........make sure you put them in the right way, if you had the (rod piston) in backwards the rod will bind on the crank.

might have to get the blocks line bore checked.........

 

Well, I got it to work. I tore it down again & put in another new set of bearings & it's fine. The only thing I can think of is maybe the thrust bearing was off, since the clearance between the bearings & journals was fine.

Thank you both for your help.