Ok so I started assembling my rebuilt 5.3 clearances. Looked ok so I re-cleaned everything installed the Main bearings then lubed them and the crank ... Crank was polished and Is withen factory spec. I used ACL duraglide Std Bearings. Tourqued everything to spec and turned the crank a revelotion or two between steps to make sure it was good. By the time it was all torued down it stoped spinning... I take it apart 1 cap at a time to see if I am having an issue at 1 specific cap... No such luck...

#1 bearing looks like it had something under the coating.

It lightly scored the crank. I am gonna see if They will warranty the bearings And try and switch them for something else like Clevites.... I am gonna take the crank down and have it looked at agian

Any one Have any Idea's or possible suggestions???

 

Do you measure the main bores and crank? Or use plasti-gauge? I would highly recommend some method of measuring other than.. "It spins"

 

Sounds like you need to give the engine to an engine shop and let them do it. Also, you need to check run out on the crank. Your crank could be twisted.

R

 

Yes I mic'd The bearing journals on the crank and checked for out of round and taper. also checked the stack up on the bearing thickness and the bore size... All withen spec. I also use plasti gauge to verify that I don't have a bearing that is not seating properly or something... I have actually caught that on other motors since I verified with Plasti Gauge...


Reason for spining crank is to make sure I dont have this such problem.


It started getting tight but I figured it was because I am withen the tighter side of the factory clearances...

 

Possible. I had all the machine work done by very reputable people They Usually tell me if there is a problem... i am going to have it looked at again now that it scored the crank... It looks like something was under the coating on the bearing as there is a round cirle around the are that were the bearing appears to be damaged... I'll try to get pics of it...

 

Dial bore gauge is the only way to build a motor. You should also inspect every bearing that you install. Also, the only way the crank does not spin is if you TQ the caps down wrong as well. Done it before. Just undo the caps, and start over. Also, do you have lube on it?

R

 

if it scored the crank with the roundness of the crank it is ok it is not good when the crank is scored across the bearing area.not saying it is good but it may be ok

 

GM Book says inside first Then out side and last the side bolts... You already know the specs... I went first pass inside, first pass out side with the side bolts in place. the second pass inside to proper degree, second pass out side to proper degree then the side of each cap from the center out ward like the torque sequence to the proper torque. I have the Helm GM manual right next to me while I am assebling this. Please advise if something does not sound right Or if there is a better way.

BTW FWIW all my tools are High End and all are kept in Excellent Like new shape.

No lube under bearings in case some one is going to ask... only on the crank journals and bearing surfaces

Rick, some one else pointed out that I may have flipped the rear main around on accedint and did not relise it... After he said that, I can NOT be 100% sure That cap was on correctly. It certinally could cause a similar type of issue... I have another set of bearings on the way. I am personally going to check the run out on the crank some time this week when I get a chance.

I certinally appericate any help. Some times it's hard to stand back and see what you might have possibly over looked...

 

Um, you leave the side bolts out when you are doing the 4 mains. You will actually see the block expand when you take the side cap bolts out. So there is a load there.

As for the 5th main cap, very easy to mistake the first time. All the front 4 have the ear tabs facing back, then the last one faces forward.

R

 

All though I thought I did It that way, It is very possible I made a mistake when I re-cleand everything for the finall assembly.... With out being able to look right now, are the caps numbered 1-4 all on the same side and the one with number 5 is flipped around so the number would be on the other side???
I am trying to picture the aseembly as I last did it in my head and I am thinking all the numbers were on one side of the block...