I'm currently putting together a ls1 short block. I've got the crank in and bolted in. It spun freely but as I added the pistons I can't find away to spin the crank as easy. I found an old crank bolt and tossed it in and it'll spin a bit and then I feel the bolt just stretching. It seems to be stuck between two points but it moves back and forth between those points. So my question is, can I find an easier way to spin the crank so I can tighten the rod bolts or is something messed up? Should it spin pretty easy with the pistons in? Maybe one of my piston rings is jacked up?

 

It should still move easily with the pistons in. You're probably doing something wrong.

 

Jason, you just answered your own question regarding the rings; better to question now than 10 hours of labor getting the motor dressed and into the car

without the rods in, you could spin the crank using the snout/timing gear with minimal effort?

I'm assuming you've done the 140degrees rotation and the oe tq procedure on the stock crank bolt a few times, getting the bolt to 'stretch' as you posted is nuckin futs if you don't have a flywheel bolted on with the KMoore locking tool

 

Do you just have rod caps snugged in place? Are they stock rods? With a complete long block and spark plugs out I could turn the crank with very minimal effort...liked suggested check everything again and save yourself some headache!

 

If you cant assemble the shortblock without "stretching" a stock crank bolt, then you have clearance problems my friend...

 

Are you building a stroker, sounds like you might be hitting the cylinder wall with a rod, pistons shouldn't add resistance when turning the crank with no heads bolted on,

 

something is def not right... better to check it now than build the whole thing and have a problem