318 rebuild question

[koshe]

I am rebuilding my original 318. It was bored .040. I installed the crank and it turned freely. The issue that confuses me some is that the more pistons I installed the harder the motor rotated. So much so that when I tightened 7 and 8 I could no longer rotate it at all. The pistons were pretty snug when I slid them in the cylinder. The cylinder walls did have a light coat of oil on them. Is this normal?? I have the book "how to rebuild your small bock mopar" and have some experience. Any ideas or am I just nuts?

[1BAD68]

When I did mine, they were pretty tight and hard to crank over by hand but they did.
If you cant turn them over with a breaker bar on the crank bolt, you probably have a problem.
Anyway, I was pretty worried that something was wrong too but 3 years later its still going strong.

[elacruze]

Did you verify that the piston rings all have gap?

Ring gap is one of the things often overlooked, because 'It's in the box'. Tight rings are forced against the cylinder walls, causing high friction.

[koshe]

How is the ring gap checked??

[elacruze]

How is the ring gap checked??

Before the rings get installed on the pistons, stick them in the bore about an inch down (using the piston top upside down is an easy way to be sure they're square in the hole) and use a feeler gauge in the gap.


Actual gap should follow the ring manufacturer's specification. If they're too tight, they have to have the ends filed with a ring gap file-