How many ftlbs of torque should be need to turn the crank, rods and pistons. Im assembling a motor for a friend and he had the crank turned and bought bearings. the plastigage is in spec but it takes about 40 ftlbs of torque to turn it over. which seems like a lot.

 

there were a thread a while back here that said it should break around 15lbf when you rotate the crank without the t belt.

with t belt on it all depends on the pressure of the valve springs and lift of your cams

mine popped at 15-16lbf as well when i rotated it

 

you supposed to spin the crank after each main/piston rod bearing you put in to make sure its not binding.

 

what kind of assembly lube you used? and how cold was it when you turned it?

you have any lube on the piston rings?

how many times did you measure the clearances and are all your bearings and rods in proper places and matched correctly?

when i TRIPPLE checked my block before puting oil pan in i finally notticed that my rod caps were switched so i checked everything again and got them where they supposed to be,

 

i've heard the numbers 20-40 ft/lbs thrown around a lot but i think these people were talking about v8 pushrod motors, so i would think 15-35 ft/lbs would be expected at ROOM TEMPERATURE.

i've built motors that seized after being left outside in the harsh winter -30*C but loosened right back up once they were brought inside so keep temperature in mind.

 

i try for no more than 15lbs with the motor at half its stroke with just the block sitting there

 

I triple check the everything last night. Plastigaged all the mains....they were fine but the one bearing had small scratches on it. I replaced that main cap and every thing is turning at 15lbs now.
thanks for your help