Two 360s, One with Cam Bearing Install Issues

[Dodge72]

So my boyfriend's building up his two 360s for his two A Bodies. Ones a 70s 360, modified by a previous owner, and anothers a 92 truck block, stock rebuild for a car. He decided to install the cam bearings himself and started with the 70s 360. Those went in time and for a first time, everything's straight and went well.

Then came the truck block.

Trying to install the rear most bearing in the back of the block. Doing the same as the other 360, but the damn bearing wouldn't go in. The bearing was scored from the tool (break in lube was used). Bought a different set of bearings, making sure it was for a 92 LA block. Tried it again, but it takes much greater effort to drive it in than the previous 360. Removed the tool to check it and it was still hanging out by a lip, and the tool's rubber collet sleeve was actually cut in half. Found the bore for that bearing has scoring on it.

Why are we having so much difficulty with this block? The other one went a lot smoother. What should we look for?

 

[GeorgeH]

As in the block bore is scored? Maybe dress it a little with emery if there are burrs. That block is nowhere near clean enough to build and be putting in cam bearings. The dirt,grit, and grime EVERYWHERE might be part of the problem and if the bore is dirty you'll have a hella time. Making it spotless is step 1.

 

[krazykuda]

Do you have the ability to measure the bore for the cam bearing??? One may be slightly smaller than the other... Or the rust can be making the bearing harder to push in...

There are some methods of using acid to clean the rust off the block, it may help to remove the rust before pushing the bearings in...

The ease of the bearings to be pressed in is affected by the cleanliness of the bores and how smooth they are...

 

[340 demon 72]

the holes in the cam bearings are supposed to line up with the oil galley holes doesn't look like there in properly !!!!!!!!!!!!!

 

[GeorgeH]

the holes in the cam bearings are supposed to line up with the oil galley holes doesn't look like there in properly !!!!!!!!!!!!!

oops!

 

[moper]

Yeah - the bearings pictured I don't believe are in properly. Also, it's up to the asembler to make sure things are ready to install. If the bearing bore was tweaked when the old ones were removed (**** happens) then the assembler needs to file/smooth out the defect(s) in the bore(s) so the bearings can be installed, then install them so the passages all line up at the same time. The test fit the camshaft to make sure it can be turned by your fingers. Cam bearings are not usually something you rush.

 

[furrystump]

Cam bearing bores can be all over the map. The bores can be on the small size and the bearings can be on the big size. The cam needs to turn easily. If it does you can try different bearings or send it to have the bores machined. There is a third option. If you have an old cam cut a diagonal groove in all the bearing surfaces. About 45 degs. Coat it in oil and slid it in. Slowly turn it. it will clearance the bearings. You may want to remove it and clean out the grooves periodically. I usually want to be able to spin the cam by hand with just the sprocket on it. Make sure you clean out all the oil passages after!

 

[krazykuda]

Cam bearing bores can be all over the map.

Not really, there is a tight tolerance on the bore diameter so the press fit in the bearings will be able to hold them in...


we machined the cam bearing bores after we installed them at the engine factory so we could hold the proper tolerance and fit of the cam journals... There was a diameter and surface finish spec... Have you ever tried to get a surface finish reading on a cam bearing... Very difficult to get in there and get a reading, especially on the middle ones....

 

[furrystump]

I knew it was not uncommon to have new cam bearings be tight. Now it makes sense why.

 

[furrystump]

must have remove a good amount of bearing material, but I guess if its the right clearance and flat thats all you need.

 

[pishta]

try hanging a piston on a magnum rod. You would swear the pins are not the right size.

 

[krazykuda]

must have remove a good amount of bearing material, but I guess if its the right clearance and flat thats all you need.

The surface also needs to be somewhat smooth - surface finish is also a factor, if it's too rough, it can cause binding...

 

[krazykuda]

If you have two 360's, does that mean you are going in circles???

 

[GeorgeH]

If you have two 360's, does that mean you are going in circles???

LOL

 

[GeorgeH]

LOL

I think the Op bailed at grit and grime.

 

[krazykuda]

I think the Op bailed at grit and grime.

Did we scare another one away???