Engine building question

[D's350GP]

Ive been thinking about this for a little while, and id like to get a second opinion about it. The 350 thats going in the GP is the first engine ive ever "built", so im using a rebuild guide and the advice of a friend of mine that has experiece building motors. id like to follow the book to the letter, to make sure everything is done the right way, but the problem is this. when installing the pistons: i went to each cylinder and ground the rings to match, put them in the pistons, lubed everything up real well, and didnt force any of the pistons in the cylinders. the manual says that when all 8 pistons are in the block that it shouldnt be difficult to turn the crank. when i go to turn it, i have to give it some force initially to get it to rotate. my friend says that its fine and his blocks have felt the same way, but id like to be sure about it. So how much force should it take to turn the crank?Thanks

 

[clean8485]

I believe that your friend is right. Keep in mind that there is a certain amount of tension between the piston rings and the cylinder walls, and when you multiply that by 8 pistons, you will need to exert some force to get the crankshaft to start moving. once the crankshaft is turning, then keeping it turning will be easier. I don't know if there is a specification for the breakaway torque required to get the crankshaft to start moving, or a spec for the torque required to keep it turning, but I would imagine that there is probably a listing in a manual somewhere for this. Hope this helps.

 

[D's350GP]

thanks alot, you've taken a great burden off my mind.

 

[RedHotRegal]

That tension will be there untill the rings break in. run of the mill iron rings break in fast, and hi perf/racing rings take longer.