Crankshaft question

I'm asking about a 350, but I guess it could apply to any motor:

If you remove all the main caps to roll the bearings, how long can you leave it hanging by just he pistons? It's still on the timing chain and has the tranny stub stuck in the crank end.

I ask because I read somewhere that they'll warp if left with no support.
I'm thinking about 3 weeks until I stick the caps back on.

Thanks,
-B.

Tim, please move this post as you see fit. I didn't know where to put it.

Brian,
Good question. I have never left one like that for more than a few days. I really don't know the answer, but I would suggest putting one of the middle caps back on. The piston/rod assemblies will start to slide down and put a lot of weight on the crank. Since you are not going to try starting it or anything, put a bearing in the cap and torque it back down. You don't need to put the block side bearing back in just the cap bearing.

I think that this is a good general discussion post because it will apply to any engine and should stay here.

Please discribe your engine side bearing removal tool/process in more detail. I didn't understand what exactly you used. Thanks

I've heard that too, but I've never seen it.

I'd at least put two caps back on to hold it up there.No reason to press your luck.

Be sure to put something around the crank journals so it doesn't get scratched because the bearings have been removed.

Oddly I agree with Ben. I've only ever done that w/the 2 end caps on. Then when the middle ones are done, do the ends. Of course... in my case new bearings didn't help.

Ahhh, thanks for the response- and Tim, thanks for the add-in. I can tell by it that we're fine and that means alot as I value you as a bud.

You know a ring clamp, like you use on a radiator hose. I opened it up and used the flat side to push the seal out from behind the crank. It was strong enough that I could put some pressure to it, but had a natural bend that followed the crank around.

I reckon I'm gonna have to put new bearings in it in the next couple of days since all you hippies said so. Ironically- my bottom 1/2 of each bearing was toast, but the top half looked fine. Is this normal? The crank was fine too.

Thanks guys,
-B.,

were the oil holes lined up??? that is strange. Could need a line bore. Hope not.

One more thing. Do you think you could have had an oiling issue when you had the problem with the filter leak. This is sounding closer to something like that than heat. Low pressure from the leaking oil filter could have oiled the top half but not had enough pressure to force the oil around to the bottom. This is just a guess. I have never personally witnessed this before. Usually have somewhat consistant wear between the two havles?

Brian,
When you said ring clamp earlier, I was thinking piston ring. You cleared that up, thanks. I know that it has been a running joke about you and torque wrenches. But, could you have not torqued the mains down all the way? To me this would explain your low oil pressure, your leak in the rear, some of your overheating problems and would put all of the load on the caps without a constant oil supply.

Just an idea and not an add on to the joke.

I don't think so- they were as tight as they should be. I had to use a cheater bar to get them off. Are you saying overtighten them? Maybe that, but they were not undertightened.

I think that it was the heat. I had no temp gauge in my truck for a while and was towing tractors and such with it and on several occasions it blew the radiator. After I got a temp gauge I saw it was up to 250. The heads had cracked and so I should have expected this.

I guess I need to check the rod's too.
-B.

You probably heated it up to the point where the oil thinnned out so badly that it wasn't thick enough to keep the crank off of the bearings in the caps. The lions share of the cranks exerted pressure is on the lower caps. The crankshaft bending from not being supported is a long term storage type of thing. Not a couple of weeks. Myth: Busted. When you put your new bearing in get a bottle of STP Engine Treatment and put some on the bearing face of the bearings...It should be in a blue platic bottle. I use this stuff on ALL my new bottom ends and got the tip from a pro engine builder.