Engine is really tight!

[Wes Flippen]

Just did an in engine overhaul. Valves, guides, pistons and rings. Used standard size pistons and rings. Torqued rod caps to 50 ft lbs per manual. Engine seems really tight now. Even with the head still off, I had to use a 3 ft breaker bar on the crank shaft to get it to spin. Used assembly lube for new valves and wrist pins and dipped pistons in oil before installing. Any thoughts?

Wes

[P15-D24]

Might want to try pre-pressurizing the oiling system with an external pot. The assembly lube doesn't last very long. 

[JBNeal]

A spun connecting rod bearing will put the crankshaft in a bind...

[Tooljunkie]

Typically i spin crank with caps tight,check end play. Then rotate as im installing pistons and rods. The only real drag would be the rings in cylinder walls. Were rings sized to bore? As in end gaps needing adjustment?

[Wes Flippen]

Checked gaps, They were actually about .002 over spec, so I didn't gap any more. Pistons went into cylinders fairly easy, just light taps with hammer handle. Crank got more difficult to turn as each piston was installed. After the second piston, I could no longer turn it with the fan. I guess my next course of action is to remove the rod caps and check that the bearings are all properly in place. May just try bumping it with the starter to see if it'll turn over.

[Sniper]

Did you check the rod bearing clearances?

 

Years ago, when I was a pup and still peed on the floor, I was putting new bearings in a 400, was worry about spun bearings.  So I put a touch of locktite on the back of the main bearing shells.  I could not turn that engine over at all, even with no pistons installed.  I didn't think it would make a difference, I was wrong.  Doesn't take much to bind it up.

[P15-D24]

Agree check the bearing clearance with plastic gauge. I'm assuming this is a 218/230, are you sure you set the rod offsets up correctly? 

[Slickster]

were the rod bearings installed dry with lube only on the crank side?  That will make it tight...let us know what you find....

[DJ194950]

Once while rebuilding another brand of V-8 motor, I could not turn over as said. When checked bearing clearances with plastic gage one bearing shell was mis-markedon the box and oversize for the cranks size !

 

Worth checking and cheap!

 

DJ

Edited October 27, 2020 by DJ194950
add box info

[Wes Flippen]

I re-installed the existing rods and bearings, as they showed no appreciable wear. I numbered everything when I took them out, but that's not to say I didn't get one swapped by mistake. Cleaned and lubed the bearings when I re-installed.

[knuckleharley]

My question is "Did you mike the pistons to see the exact size,and did you run a mike through the bore to size it,also. You said it seemed to get tighter with every piston you installed,so that would be the first place *I* would check.

It is not unheard of for machine shops to bore the blocks to a different overbore than the customer wanted. Or for piston manufacturers to send the wrong size pistons.

[Slickster]

Plastigage time...

[Wes Flippen]

Got it. Seems as if I had swapped the caps for the #1 and #6 rods. Must have been just enough wear difference in the bearings to cause binding. Spins okay now.

[Sniper]

Doesn;t take much.  I learned long ago to spin the crank around at least once after each rod was installed and torqued, when go back and retorque each rod once all were installed.

 

Glad you found it and glad you let us know the issue.  Thanks.

[dpollo]

some ill informed people may regard that big lump of cast iron as being pretty crude

but it is actually a precision fit machine..... as you have recently learned.

 

with the care you have exercised, your overhaul should be a long lasting success. Best of luck.