goohead

Thoughts on this damage? Spun bearing or thrust?

Just bought an used block, comparing the ridge of this main journal in first few pics of #2 main vs the last pic of #5 main.




#2 main

#2 main

#2 main

#2 main

#5

Know It All

Looks like spun mains that someone tried to repair. It might be okay if it was repaired correctly and the bores are to size. Timing chain may be a little loose.

RonSSNova

iTrader: (3)

Look at the mating surface of the caps. You can tell if they were cut prior to line honing.

You need to torque the caps up in sequence then measure the bore diameters. That will tell you if the block is ok. It might need an align bore job.

Timing chain might end up a bit loose.

Got a machine shop you use?

WE TODD DID

iTrader: (2)

Make sure the caps are tight in the registers. Measure journals and check for roundness and taper. Then if it's good put a crank in it and torque it all down and see if it spins nice. Use motor oil not assembly lube. Shouldn't have any hard spots and breakaway from a stop effortlessly

WE TODD DID

iTrader: (2)

Btw, the caps are on backwards.

G Atsma

Yup, you do NOT match notches together.

Che70velle

iTrader: (6)

Gen5 block?

goohead

Yes it is a gen 5 block, don’t see many people doing engine repair in the gen 5 forum...but gen 4

hmm all the caps are orienated correctly from 1 (bell housing) to 5 front of block..

does that mean these main caps are from a different block (gen 4 ls?)

WE TODD DID

iTrader: (2)

I have not had a gen 5 block apart, but the tangs lined up doesnt seem right. Wont actually matter when the caps are torqued down so as long as they are in the correct spots which they arent. 1 goes to the front of the block. 5 at the rear. The diagram you have just has a number callout "1" for the caps and so happens it points at the #5 cap.

goohead

Yeah seem strange, I built other engines, mostly import/German. This is my first ls based engine build.

I hear you, even when I do rods tangs on the same side but opposite width of the bore. I just went by the service manual, the way I interpret the picture was “1” was suppose to be by the fly wheel and going 2,3,4,5 to the front. and all the “<“ facing towards front of the engine.

Are you saying this is common and should flip some of the caps so the tangs site opposite width of the bore and the order should be (back/flywheel) 1,2,3,4,5 (front/timing) covers?

WE TODD DID

iTrader: (2)

Go with the arrows facing the front of the engine, and put the caps 1-5 from timing cover to rear cover. You diagram just references "1" as the main cap, not necessarily the #1 main cap. Don't worry about the tang orientation it seems wrong but doesnt matter so as long as that's how it was when the block was align honed

Che70velle

iTrader: (6)

On gen5 engines the tangs line up. Not sure why, but every one I’ve seen is like that. That’s why I asked if it’s a Gen5.

FormulaBoat

iTrader: (1)

Older motors put tangs on same side as well (pre-LS). This was one assembly point that I noticed vastly different about the LS family. The tangs don't totally hold the bearings 100% from rotation in the block, the amount of bearing crush during cap torque down does. If it was or is getting align-honed at all, you'll want to try to find out which way the caps were on when that occurred or does occur.