1956 Century cam-bearings

[Guest imported_NikeAjax]

First let me say thanks to Joe for the heads-up on the cam-bearings! But, now I need to know how do I get the cam-bearings out of my 1956 Buick Century; but a better question is: how do I get them in; does the engine need to be out; do I use a special tool. The shop manual says they need to be honed after being put in; OMG! How difficult is this job going to be; the manual is quite vague on this subject, so I’m at a bit of a loss.

[NTX5467]

I'm not sure how the particular cam bearings are for your vehicle, but I'll speak from generalities on other engines.

I suspect that if you check the hole sizes in the block and/or the journal diameter on the cam itself, you'll find they are not all the same size, but they might be on this engine (again, speaking from generalities), as you go front to back in the block. There is also a "knocking" tool that you use to remove and install the bearings with--this makes it more of an "engine removed" operation, but I suppose you could so it "in chassis" with all of the grille, radiator, a/c condensor (if equipped), and any other item on the body removed--plus any engine item on the front of the motor so you can get to the timing chain area. Then there's the valve train items of lifters, push rods, rocker arm items, valve covers & gaskets, and other related items that would need to be removed too.

First, the existing cam bearings are knocked out. Then, the new ones are correctly positioned on the tool (looking for the correct orientation of the oil holes and making sure they will be in the block correctly when installed--as spec'd in the service manual). Key thing is to also make sure they are installed "square" in the cam bearing saddles! Another reason to have the engine on an engine stand or secured to a work bench as leaning over the core support/fenders can be tough.

So, you can remove the bearings from the front to back, but installation is from the back to the front. If there's a core plug in the back of the block, make sure it's in good shape too and don't push the cam too far back as it might damage this plug.

As for the honing operation, that might not be necessary. Key thing is to make sure the cam just slides into the new bearings and turns easily. Some machine shop guys will get out their pocket knife and do some minor selective trimming on the offending bearing if one's just a hair tight, but honing would also be something that would probably be done with a completely newly vated block so that whatever grit might result from the honing operations could be washed out of the block. I suspect that, typically, if the bearings are correctly installed in their respective saddles that maybe just a little polishing action with some red ScotchBrite might be all that was needed, but it can create "grit" too so the whittling with a pocket knife might be the best way in some cases.

When installing the cam, you can put some prelube on the journals and then carefuly feed the cam through each of the new bearings until it's all the way in. Putting a long bolt(s) in the timing chain bolt holes will make it much easier to handle during the somewhat tedious installation process. When it's all the way in, then see if it spins freely and easily. If not, then you can pull it back out again, wipe the grease off of the bearings, and look for shiney places on the new bearings that would indicate "high spots". They you can go from there as to what you do to remedy them or smooth them out.

I know there are many things in the way of engine service that used to be done without removing the engine from the car, but now that we have more ready available capabilities in modern times, pulling the engine is probably the easiest way to do something of this nature.

Of course, with the engine out, you can also fully check other things like the rod and main bearings too. You'll also have to remove the complete set of pushrods, lifters, etc. to do the cam bearing deal, but I don't think the heads would have to be removed so completely taking the motor all the way apart should not be necessary. Joe might have some additional comments and I welcome them.

Enjoy!

NTX5467