blue86iroc

iTrader: (2)

I'm re-ringing my 350, and it's still in the vehicle. I've only pulled three pistons so far, and one of them has a few nicks on one of the bearing halves... they're very slightly raised, not flush with the bearing surface. I didn't nick it during removal. Before pulling the piston, I checked the bearing clearance (with Plastigage -- yeah, I know) and it was within spec.

I'm looking to find the best course of action. Is there a way to "fix" the nicks, or should I spend the whole three dollars and buy a new bearing? If I do that, is it worthwhile to just put all new rod bearings on the motor? The crank journal looks fine; no marks or anything.

The nicks are on the right side of the bearing.

porkyzilla

iTrader: (1)

quit being a tight *** and spend the money got the motor apart might as well. remember NEW IS ALWAYS BETTER

ede

as cheap as bearings are it isn't even a question, replace them

blue86iroc

iTrader: (2)

Haha, porkyzilla... I don't want to be a tight ***. Buying a new bearing isn't a problem; I can afford the pocket change . I was just unsure if installing only one new bearing would cause problems if the rest weren't new bearings. Thanks, guys.

porkyzilla

iTrader: (1)

why dont you replace them all??? engine is apart? and heck your re-rigning might as well go all the way

blue86iroc

iTrader: (2)

Yeah, you're right. I already need at least four, so I think I'm just going to buy the rest.

I should probably do main bearings, too. Can I safely remove the rear bearing cap with the transmission still attached? Will the extra tension on that part of the crank affect the torquing of the cap bolts?

8Mike9

Is anyone going to point out the obvious here?

The bearing would be the least of my concerns.....

SSC

Whats that Mike, The topic or the worn camshaft in the pic?

8Mike9

Tell ya the truth, I didn't even look at the cam

Just my observations, but the bearing looks scarred, which would indicate the crank journal probably is too.

Next was "re-ringing". If the engine needs it, then I'd have to figure the cylinders are tapered, and most likely ring groove too, which needs to be removed for the new rings...so there may not be much long term benefit to installing new rings.

I'm not flaming, I just hate to see so much work being done, for (IMO) little/short term benefit.

blue86iroc

iTrader: (2)

I should probably clarify why I'm doing what I'm doing...

I blew a head gasket, and I sent the heads to the machine shop to get pressure tested and decked. Since I had everything apart, I figured that it'd be a good time to check the timing chain, etc. The chain needs replaced. I'm installing a new cam while I'm in there. The heads need more machining to work with the cam, so I'm getting a valve job, screw-in studs, cut valve guides, and enlarged spring pockets. The machinist suggested that since the top end of the motor will be sealed properly, I should re-ring it to seal the bottom end. He also suggested that I check the bearing clearances (which turned out to be OK).

The car never *needed* new rings, cam, timing chain, or bearings. The motor always ran just fine, and the only problem I ever had was with the head gasket failing. The parts may be worn, but that's to be expected.

I guess that this could go on forever. I'm already doing way more than I had ever intended, but it's a little hard not to when the motor is all torn apart the way it is. Right now, I don't have the capability to pull the motor, and a full rebuild is out of the question.

blue86iroc

iTrader: (2)

I just wanted to post a picture of one of the crank journals... it looks "normally worn" to me, but this is the first time I've ever torn down an engine -- with the intent of putting it back together again .

RB83L69

The crank looks "normally" worn to me. Which means, since it shows wear, it needs to be turned, and new bearings in the appropriate undersize installed along with it.

As critical a place in the motor as that is, it's a pretty poor idea to try to cheap out right there, while you've got it apart anyway.

8Mike9

I'd have the shop inspect the crank, problem is if you have any grooves (which I can't tell) the oil will run in the groove, not fully across the journal/bearing. Then you get wear, which leads to spin.

Now would be a good time to have the crank checked, might just need to be polished.

I know what you mean about things turning into more than expected.

Someone on here has this in his sig-line:

'Weekend projects, aren't"

SSC

Well if it was my engine and I wanted to cheap out on the bottem half which I would never do for any engine expected to live a long happy life. If all the crank journals look like that one in the pic it just needs polished which you can do safely with a good abrasive material like scotchbrite, the pads you find in the autobody section not the stuff under the sink. After a few (light) passes if should clean up fairly nice and may or may not need undersized bearings. Either way you might as well pull the rest of the engine out 11 bolts wont kill you.

posbird87

i would just remove the trans which can be done with hand tools and a jack and then remove the main caps and crank.

then just lift the engine block out, they arent too heavy.

blue86iroc

iTrader: (2)

Argh, I guess I'll just pull the motor. I'll just have to create the capability to pull the motor. Everyone I talk to, including you guys, tell me that I might as well get it done.

8Mike9, I think "weekend projects aren't" is Jim85IROC's sig. It IS so true...

RB83L69

Yeah, it kind of bites; but once you've got as far into it as you already have, it's senseless to put it back together without refreshing the whole thing. Put that worn-out stuff back in there, and you'll find yourself tearing it down about this time next year, thinking to yourself how you just put new head gaskets and rings in it, now its oil pressure is going away. Because it looks to me like that bearing, and even more so the crank, are approaching the end of their service life. Might as well do it once, be done with it, and not have to fool with it again for a long time.

Mic the rod journal at 2 points, 90° away from each other; take one reading from the outermost point to the innermost, and take the other across the "sides" of the journal. If they're more than .001" different, then the crank is for sure used up.

Even if the crank is OK, put in new bearings.

blue86iroc

iTrader: (2)

Very true, RB83L69. Thanks for the instructions on checking the rod journals... I'm curious to see the reading that I get.