rncotton

First, a very brief history. 2001 stock WS6 w/ broken ring land on piston, sent to local performance shop for rebuild, low oil pressure, diagnosed as "spun bearing" and they rebuilt it again. Within a month, low oil pressure, diagnosed as spun bearing, and they rebuilt it again. Short time later, making noises. During the process of diagnosis, they dropped valves and motor went kaboom. Cracked block, trashed heads, trashed internals, blah blah blah, melt it down for beer cans.

They obtain a block and crank, scrounge up enough parts to build me another motor, and less than 4,000 miles ... starts making noise again. Remember, this is a totally different motor. This time, I just pulled it out myself, disassembled the motor, and found a spun bearing. http://www.rogercotton.com/misc/bearing.jpg

Obviously, I'm not sending it back to the same place. They are out of business anyway. As far as they are concerned, "It ran fine for 5 months, so it obviously wasn't a build problem." I bought a book on rebuilding LS1 motors, have good mechanical ability, and am rebuilding it myself this time.

So now my questions. What exactly do I need to have the machine shop do for me? (and can anyone recommend a good machine shop in the greater Memphis area?)

The head gaskets are one-time use, but what about all the others like water pump, valley cover, intake ports, oil pan, front/rear covers? Those all look in great shape and the builder said they were new when he installed them, so less than 4K highway/city normal miles.

Thanks for the exceptional advice you always offer. In the interest of cost savings, I want to reuse all my stock hard parts if possible. I assume the machine shop can tell me if they are OK or need to be replaced.

Always2Slow

iTrader: (8)

Well since this is coming out of a junk motor your going to have to send the rods to the machine shop to get looked at for out of round and possible reconditioned. Switch the rod bolts to katechs while your at it. Have them check the crank for out of round and roughness maybe it might need to be cut .010. You could have them hone it out and buy new pistons i don't know what your cylinder walls looks like or your piston skirts. Its possible to have them just re ring the stock ones if everything looks good with a slight re hone job. That is pretty much the jist of it if your using stock bolts to reassemble the motor. If using main studs you will need to line hone the block. I would have the assembly balanced as a whole when everything checks out. They can get it balanced better than the factory and less worry when you have it together.

rncotton

Cylinder walls look great, pistons look great. Planning to simply have the cylinders lightly honed and get fresh rings on the stock pistons. Rod bolts .... $80 for a set of ARP's so yeah, planning to replace the stockers. Already have ARP head bolts.

Any idea why it kept spinning bearings, on two different motors? Poor choice in their machine shop or poor installation / improper torque, etc ?

Gaskets anyone?

JRENIGAR

iTrader: (37)

I work in memphis and have heard bb&t in southaven, ms does a good job. Friend had a 93 lightning with 351 windsor redone there and its going strong after 60k with heads n blower on it.I have also heard there expensive. BTW who was the shop you took it to? I hope not gotera racing, they did a hack job on a friends 02 mustang 4.6 engine.

rncotton

BBT, expensive, long wait, multiple delays ... but yes, quality work.

No, it wasn't Gotera. The shop I used is out of business.

Always2Slow

iTrader: (8)

The reason you keep spinning bearings is either improper clearance or improper assembly. A lot of these older shops that have worked on old school stuff try to assemble the ls1 the same way and because the block is aluminum it requires different clearances than most are used to. The fact its rod bearings and those are the same clearences as a cast iron motor, the shop you took it to could have been both combined.