Need help with crank removal.

[derikleon]

Ok so I’m trying to replace the Rod & Main bearings in my 350, with out pulling the heads.

I’m just wondering how much of a hassle it’s going to be to get the crank back in when it comes to fumbling around with all the rods. Are they going to fall in to the tops of the cylinder walls & become a pain in my ass later on?

Any suggestions would be appreciated

Thanks guy!

 

[4X4HIGH]

If the engine is out and on a stand (which it sounds like) it can be done without much hassle. Something to consider though is that LOTS of GM cranks used what is called a "selective fit" bearing and cannot be bought anywhere. These bearing usually range anywhere from .0001"-.001" undersize. If your crank uses these bearings and you try to install standard size bearings your clearances will be too much and low oil pressure will occur. Hopefully you plan on having the crank machined and the proper size bearings supplied then you won't have any troubles. The biggest thing you need to remember to do is to install rod bolt "booties" on the rod bolts so they don't hit the crank journals and leave dings and scratches on the surface. If you don't have any of the "booties" then use a piece of fuel hose cut to a proper length to serve this purpose.

This is the best advice you'll get from the resident machinist here on CK5.

 

[derikleon]

Yes it on a stand & I already have the fuel line cut to length for the “Booties”, as far as the selective fit bearings, this is the first time I’v heard of them. The engine I’m working on is an 89’ so I don’t know if there going to effect me or not.

Lets see if I can further explain my question-

Once I pull the caps on one set of rods, I’ll need to turn the crank in order to bring up the next set & buy doing this I will have to slide the last rod/piston down so that the crank can also rotate down. & by the time I’m done, I’ll have all the rods pushed down. Then I pull the crank. Now when it comes time to set the crank back in, am I going to have problems pulling the rod (with new berrings) back up to the crank?

Maybe I’m just thinking into this a little to far, but its not like I could just reach down there with pliers & pull them up, specially with the newly machined crank & fresh bearings set in the rods.

 

[4X4HIGH]

Don't push the rods down, turn the crank and let the crank journal move the pistons to TDC this way they don't go any further than needed. They shouldn't be able to go much further anyways but safe than sorry. Also when you go to reinstall the crank, carefully lay the crank in place moving the rods into position so that none are in the wrong place then carefully you can stick a pry bar under the rod bolt and draw the rod back into place.

 

[derikleon]

Hey thanks alot!

 

[doonjumper]

Yes it on a stand & I already have the fuel line cut to length for the “Booties”, as far as the selective fit bearings, this is the first time I’v heard of them. The engine I’m working on is an 89’ so I don’t know if there going to effect me or not.

Lets see if I can further explain my question-

Once I pull the caps on one set of rods, I’ll need to turn the crank in order to bring up the next set & buy doing this I will have to slide the last rod/piston down so that the crank can also rotate down. & by the time I’m done, I’ll have all the rods pushed down. Then I pull the crank. Now when it comes time to set the crank back in, am I going to have problems pulling the rod (with new barrings) back up to the crank?

Maybe I’m just thinking into this a little to far, but its not like I could just reach down there with pliers & pull them up, specially with the newly machined crank & fresh bearings set in the rods.

You wont have any problems at all. You will be able to pull the rods up to the crank with ease. They don't slide that far down in the cylinder. Thats just it...the rods wont "fall" into the cylinder. They will stop once clear of the crank because of the ring pressure that is against the cylinder walls. Just be careful when assembling. Use the above mentioned boots or rubber hose and plenty of lube. You can never have too much lube.

 

[derikleon]

You can never have too much lube.