Too tight??

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harvenator

harvenator

A fish called Wanda
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I had my block bored .040 over and have installed new pistons and rings. When I installed the crank it rotated with ease. As I intalled each piston, the crank got progressively harder to turn until when the 8th piston went in I couldn't turn it with an 18 inch combination wrench on the crank bolt and I haven't even torqued the rod caps yet.

Any ideas?
I have all the rod weep holes facing the opposite cylinder. I prelubed the cylinder walls with oil as well as the piston rings and skirts. Assembly lube on the rod bearings and journals.
 
Something is binding?

did you Plastigauge the main bearings before assembly?

What does the manual say? I thought you had to torque the main caps before installing the pistons?
 
Lots of things can make a crank hard to turn; lack of lubrication (did you use plenty of oil on the parts when you put the pistons in the cylinders?)

Ring end gaps can be too tight.... they need to be checked for proper gap before you install the pistons.

Rod bearings need sufficient clearance to turn freely... two and a half thousandths should work okay, but it's important.

Were the rods rebuilt? A twisted rod or tight wrist pin can make a crank hard to turn. The rods need to be checked for straightness on a fixture.

Piston to cylinder wall clearance is critical and can easily be too tight, causing the symptoms you're describing.

Was the crankshaft checked for straightness? Some kinds of trauma experienced by the cranksfat, itself, can "warp" the alignment of the main bearingsm and cause a bind when the caps are installed.

Main bearing clearance is another critical area that, if too tight, will make a crank hard to turn. On a 440, three thousndths would probably be a little loose, but would likely work okay in the long run. You can ch=ck this with Plastigage, if you don't have the proper micrometers to check the crank bearing diameter and installed bearings.

I'd think that anything over about 30 foot-pounds to turn this crank over would indicate something, somewhere, is too tight.

i've probably forgotten a few trouble areas, but this will get you started.

Good luck!!!:cheers:
 
Are all your rods/pistons facing the correct way?
 
as far as I can tell -- the little holes in the rod cap is facing the opposite cylinder and cam area.
 
I had a machine shop bore the block, they also turned the crank .010 as well as the rod journals .010. All bearings were .010 over. He also cleaned up the pstons and looked over the rods. I did NOT check all the rings for end gap, BUT when I tapped the assembled piston/ring assembly into the cylinder from the ring compressor, they actually slid down the cylinder with only a little pressure on the hammer handle.
 
Did you check to make sure that the rod bearings had proper clearance at the edge against the journal chamfer. Depending on how the crank was turned you could have an inteference at the rod journal chamfer.
 
Steve68 said:
Did you check to make sure that the rod bearings had proper clearance at the edge against the journal chamfer. Depending on how the crank was turned you could have an inteference at the rod journal chamfer.
Click to expand...

That is exactly the first thing that came to mind. The rods need to be installed with the chamfer towards the crank. then check the rod bearings on that side for a chamfer also.
 
It didn't take me 8 months to solve the problem -- it just took me that time to get back to this thread. Actually, I thought I had the caps on correctly but there were 2 that looked like the were right but upon closer inspection -- well -- I screwed up. Thankfully, I caught it. Still haven't installed the engine but hope t do the swap after I caome back from vacation in July. I figure a little 2000 mile motorcycle trip might get me motivated.
 
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