Im rebuilding th 350 out of my 79 camaro. Yesterday i was puting the pistons in and after i put in the last one ( in the number 7 cylander) the engine wont turn at all. If I losen up the nuts on the connecting rod the enigne will turn. Do any of you guys have any idea whats going on.

 

Wrong size rod bearings? Has the crank been machined, or is it how it was when you took the engine apart? If unchanged, did you match up the specs from the old bearings to the new? If the crank was ground, then you use undersized bearings and they would be stamped on the back side. But undersized bearings won't work on a standard dimension crank journal. Oh, and you been using assembly lube on the bearings, and oiling up the cylinder walls well?

 

The crank is the same as when I removed it. And yes I have been using assembly lube and oiling up the cylinders. I don’t think I made it clear in the first post but it is only the #7 cylinder that won’t turn. All the others turn fine when torque to the 45 ft lbs.

 

are the chamfered edges of the rods pointing towards the outsides? If you look at the rod where the bearing goes you'll notice one side is more chamfered than the other. That side of the rod is supposed to be towards the outside. Could be that when they pressed the piston on they got it backwards.

Also, are you sure you're putting the pistons in the correct bores?

If you need me to take some pics to show what I'm talking about I can. I have a set sitting here beside me.

 

i think you may be right about the rod being pressed on wrong, im at school so i wont be able to check untill this weekend. Also the the rods were all labled to the cylinder there supposed to go in. could u take some pics though for me?

 

Yeah, a friend of mine had the same problem a few weeks ago. If the rods are pressed in the wrong direction they'll bind.

 

I checked the piston today and it is pressed on right. I also checked the tolerance of the bearing and got .0015 in. From what ive seen is supposed to be around .002 in right?

 

measure bearings for cyl # 7 as compared to the other 7 cylinders

did u use new bearings? place might have accidentally sent you one underbore by accident