The Stovebolt Site Forums The Shop Area Engine Shop 235 rebuild......crank/mains

Starting the rebuild. Did anyone encounter an issue with torquing the mains to the recommended 100-110? My crank is almost impossible to turn at 90, so I have backed them down to 85. Using Clevite mains. Any stories or simular results? Don't want to go to far as 90 seems to be stretching the bolts if you know what I mean.

Hank

Your bearing clearances must be off or the crank is bent? With clearances correct, there is no way it would lock the crank by torquing down the mains.

Are the clearances being checked with Plastigage as recommended by Chevrolet Shop Manual? Another link from the Shop Manual on assemby instructions. Finding the right shims can sometimes be a problem. The last time I put a 261 together I bought shim stock from McMaster-Carr. If the crankshaft does not rotate easily ( less than about 5 ft-lbf of torque) at the specified torque with the specified bearing clearances, the crankshaft may be bent or the block may need to be align-bored.

I did run into the problem that you describe, back in 1961. The block needed to be align-bored. The 9/16" main bearing cap screws can easily accept 100-110 ft-lbf of torque.

What type of rear main seal is being used? If it is not installed properly it could be causing a drag on the crank.

Hoyt

Check the clearances as the others have mentioned. You'll probably have to shim the mains, there should have been a shim kit with the new bearings. I used Michigan 77s in mine, and they did include the shims and the Plastigauge material.
Side note, I did have an issue with mine on the rear main. One of the bolts broke, not even at the full torque. Got paranoid and sent in the torque wrench (Snap-On) for recalibration, but also consulted with the machine shop that did the work. Seems that particular bolt was bad to begine with. Had a very hard time getting a replacement, as no one makes a direct fit replacement, not even ARP. Odd thing is what truned out to be a direct replacemnt, a John Deere deisel head bolt! Before you ask, yes, I got them from the Deere dealer, so I can actually say my 235 Runs Like A Deere! At least the mains arent arguing with the IH carbs that are onn the intake.

Thank you all for the advise. I appreciate it. I will call and get a set of shims and see if this helps my problem.

Hank