I was told by a machine shop that you cannot install cam bearings with the rotating assembly in because you cannot get the bearings thru the front of the block. I was also told by a buddy that because the cam bearings are different sizes, you can install them thru the front of the block if you have the right tool. Who is right here?? Thanks!

i usually have a machine shop do cam bearings, as they have to be indexed for the oiling holes in them...just cheap insurance to have an experianced machinist do it...but i believe they can install them with the crank in it...

My first thought is that you have to remove them, with rotating parts in place its tough and you have to get the tool into the center of the block to start pushing stuff outwards. And you have a chance of messing up the bearing or getting hole index off or both. Easier if you just loosen rods off caps, pull aside and remove crank then have at it. Replace main seal and look at bearing while you are at it.

Dubs,
Your friend is correct as far as the sizes go. You might be able to do it, but I cannot even imagine trying. How are you going to get the oil holes aligned if you can't even see them ? Its hard enough with the bare block on a stand, never mind in an assembled engine.

Besides, If there is something that wrong that the cam bearings need replacing, the engine should be coming apart anyway.

Just my opinion,

..Your friend is correct as far as the sizes go...

Bill, I'm pretty sure that's not the case. :)
"All cam bearings are the same diameter but their lengths and oil holes are different. Bearing except 1 is short by almost 1/8"...(Post 65-66) "Bearing 5 has a single oil hole and no groove. Bearings 3 and 4 are identical, while bearing 2 has a chamfered oil hole.". HP Books "How To Rebuild Your Big-Block Chevy". Pg110

It might be a bit tricky, but I also think getting a cam bearing in with the rotating assy in place might be possible. Although, I admit that I've never tried. It would be quite hard to get the bearing on the install tool once it's in there unless you can borrow a 3 year old's tiny hands!:p

Find out for yourself!;)
http://cgi.ebay.com/ebaymotors/Universal-cam-bearing-tool-installer_W0QQcmdZViewItemQQcategoryZ43998QQhashZi tem150085230324QQihZ005QQitemZ150085230324QQrdZ1QQ sspagenameZWDVW
http://img181.imageshack.us/img181/7571/engineblackout111vf2.jpg (http://imageshack.us)

Nice bottom end! We can eat there too. We all like to do the right thing and you are correct it MIGHT be possible, but lets do it right. That bearing pusher is large and hard to slip thru those rods. I would never attempt.

Bill, I'm pretty sure that's not the case. :)

Steve,

Camshaft bearing bore sizes:

#1 2.1395"-2.1405"
#2 & #5 2.1295"-2.1305"
#3 & #4 2.1195"-2.1205"

So I guess it might be doable but I would never try it.

Thanks guys!!! I am going to hold off and do it right......cuz "If I don't have time to do it right.....I'll have time to do it over"!!!!

I agree with Don.....You do have a nice bottom end! LOL

Camshaft bearing bore sizes:

#1 2.1395"-2.1405"
#2 & #5 2.1295"-2.1305"
#3 & #4 2.1195"-2.1205"

...

The fiqures Bill gives are correct ...

The O.D. of the bearings for the given locations are as BillK states.
The I.D. of the Block cam bores are bored to accept the bearings in those locations.
The I.D. of the bearings once installed is the same - in the range of 1.9485~1.9492".
The O.D. of all the Cam journals is the same.

Hope fully this will be searchable in the future ...

As for "So I guess it might be doable but I would never try it" :D
Yup, it is ;) - I did a set in an old 366 dump-truck motor without pulling it out of the truck many years ago ( How many know the meaning of an "In Frame"?) - I did pull the crank, but left pistons and rods in place in the truck. Had the thing done in @ 6~7hrs and back on the road. It was not much fun - but, it was a normal "Flat-rate" procedure :(
I don't miss those types of Heavy line repairs ...

John

Thanks for the bottom end compliments, and thanks for the heads up on the bearing sizes. :thumbsup:

Bill, where was that info published please?

Steve,
I have it in my AERA Prosis software www.aera.org , but any bearing catalog has it too. I use the Clevite catalog at the shop.

Most Chilton or Motors manual have these specs in the engine section.