The Stovebolt Site Forums The Shop Area Engine Shop 235 main bearing help

I'm now ready to reassemble my engine. The crank was ground .020, the head has new valves,guides etc., etc and the block was decked and tanked. I painted the block and cleaned all the passage ways out real good. And what do you know I screwed up the first thing I touched. I put the thrust bearing in the wrong location and tried to push it in place. I finally realized what i did after i tried to put another bearing into the rear intermedite are and it was real loose. So I finally pulled all the bearings back off and put them in their proper location. I set the crank in and used plastiguage on the journals. the clearences were .003, .002, .002, and .003. which seem ok. when i put all the bearing caps on and torked them down i had trouble spinning the crank. so i loosened the thrust bearing cap only and she spun freely by hand (no seal yet). could i have ruined the thrust bearing by trying to force it in place? i'm new at this and think i know what i'm doing but this is so critical...any advise.....

pork

porkchopstein:
I just helped a good friend drop his crank in a 261. We torqued it down and it would not move. Untorque one bearing at a time and see if the crank is free between each untorque and retorque. We found that one middle bearing cap was in wrong. Once we changed that it was fine. Make sure that the F on the second bearing and R on the third (thrust?) are nearest their respective sides. The letter may seem to be upside down.

I hope this helps.

Mark

Pork,

What year is your engine? 53-55 1st series 235s used main shims, 55-62 2nd series didnt. Check to make sure all your bearing shells are the correct undersize, and that all caps are installed the correct direction. Also make sure that the bearing inserts are seated in the caps/saddles correctly.

You used assembly lube, right?

You see any serious marring or gouging on back of thrust main insert where you forced it in? Was the thrust main deformed or bent at all when you removed it from its improper position?

Did you "tonk" the thrust main while it was still loose? What was the crank end-play?

chip

chip....
i've read some of your issues/posts as well so I know you've had some issues as well with your rebuild...1st off mine is a '59 so i believe i do not need shims. i did use plenty of lube and i did check for end play and it was ok between .003 and .009. like a dumb [censored] though i tried to force the thrust bearing into the front intermediate. so i guess what i'll do is pull the crank out and then just tork down the caps with the bearings in their and measure the diameter. when the thrust cap isn't torqued down it spins free, but once i torque it down it's tough to spin...you mentioned to make sure the bearings are in properly...the bearing caps are the confusuing ones. how do i know thier in the right way?
thanks
pork

Your bearing insert is probably distored now,may have to buy a new set. If you trust Plastigauge,003 clearance is on the loose side of service limit, a freshly ground crank should be around .0015-.002 bearing clearance for a non racing engine.Either buy or borrow gauges or take the block back to the machinist for him to check while you watch.If you do a mock up assembly without the rear main seal,always a good idea, use motor oil on the bearings,if the machining is done right, the crank will spin easily even with .0015 clearance.We all make mistakes, just some of us won't admit to it