spdrcr7882

I had unexplained low oil pressure recently, so I took my k member off, and dropped the oil pan, becuase I was thinking the bearings were shot. One of the bearings was turned 1/8 of a turn out of place. I haven't taken the rod bearings out yet. but the main bearings all have discoloration and look beat. I am gonna take the crank out and have turned, will this be ok with a new set of bearings? Do I need to take the engine out and have work done to the block? I am really hoping I don't need to take the block out, since this was already a ton of work so far.
Thanks for the help
Justin

spdrcr7882

So, does anyone know if I'll need to do any machining to the block becuase of a spun bearing?
Thanks

BlackScreaminMachine

iTrader: (17)

If **** has gotten through the motor, then cam bearings may be wiped out too. In theroy if you can pull the crank, have it cleaned up or turned and put in the appropriate sized bearings and then replace the oil pump you can chance the cam bearings.

Id still run straight weight oil through a few times to clean out the old stuff. After you install the crank.

LS-1Z28

iTrader: (6)

I'm no mechanic but if all you're doing is replacing the rod and main bearings for a spun bearing you shouldn't have to take the engine out. But, it would probably be a lot easier to work on it if you had the engine on a stand.

Firehawk441

iTrader: (41)

If you spun a bearing in a rod, you should have the connecting rod checked or re-sized for out of round condition. If you spun a main bearing, there is a very good possibility an Align bore will be in order...

mike c.

iTrader: (1)

a spun bearing is just what you need to build a 408 or 427ci motor.

spdrcr7882

I took the crank to a local machine shop, and he said it wasn't in bad shape, and only needed to be polised. not bad enough to need to be turned. I ordered the bearings from the machine shop and plan on reinstalling everything in the next few days. I purchased the car already built, and was told the engine was built. Is there an easy way to tell what studs were used, arp or stock?
justin

joecar

So engine is still in car...?

ARP fasteners usually have ARP stamped on them somewhere.

89 formula350

iTrader: (8)

stock were 6 point heads and ARP would have 12 point.


good to hear the machine shop was willing to polish the crank so many would jump at turning just like people who bore blocks (most don't need it)

janaka

iTrader: (7)

I love this. I'll tell my wife that exact thing if this ever happens to me.

spdrcr7882

Engine is still in car, took out the k member, and took oil pan off once this was removed. Wasn't excited about unhooking the entire engine wiring harnesss, exhasut and intercooler piping. The studs have the twelve point nuts, so they must be apr.
Justin

spdrcr7882

ok, so I am reinstalling my crank as soon as I can pickup my new bearings from the shop. After doing a bunch of reading on tech, I am seeing that arp reccomends that you torque and loosen and torque the bolts 4 times and that you should only use arp moly lube when doing this. Since these arp studs have already been installed once, do i need to do this? And do I need to use their moly lube? In addition, When I took the rod ends off I put them in order on the floor, but of course they got knocked over. They should still be in the same order that I took them out, but is there any markings on them to indicate which rod they go back on, and also a way to know if I am installing them the wrong direction, 180 degrees off?
Thanks
I am doing as much research before I begin to reinstall the crank so I have a good idea of what to do when Im under there.
Justin

tylerdurden

iTrader: (2)

The caps will only go on one way and to there respective rod, since GM employs crack-rod technology. What kind up oil pump are you using? Did you every determined the reason for the oil pressure loss. Its already to late to find out if the oil pump was centerd on the lower timming chain gear. If you do not find out want caused the low oil pressure it could haunt you again.

01ssreda4

iTrader: (96)

Good luck with this. I would honestly recommend a new oil pump, just for "better safe then sorry"

spdrcr7882

I am going to use a new pump, don't want to have to go through this again. Does anyone know if I need to use the arp moly crap, and if I need to be going through the torque and loosen process on these studs since they have already been torqued and used?
Thanks
Justin

68 RS Convertible

iTrader: (1)

No you don't have to go through the entire torque and loosen process, thats only if your installing them new. I would do a two step torque sequence though, start at like half of your total torque value then bring it up to the full amount. I would use the moly lube. Check the arp web site, I think they give u a torque value if you just use a 30 weight oil instead of the moly lube.