So I had pulled the 455 out of the GSX to replace the crank seal and fix the oil pan that was bent up. I replace all the timing cover bolts with stainless steel ones, fix the pan painted every thing up and was getting ready to put the pan back on, rotate the engine on the stand, look down into the motor and see that all the cam bearings are squished out toward the front of the block. This sucked! :rant: The engine had good oil pressure and ran strong before I parked it to start the resto. This GSX had been rebuilt in 1984 or 85. It was then parked until mid 2007 when I got it. It might have 500 miles on the engine since the rebuild. I got the cam out today and it is an Erson JB200 (I think 118 lobe spacing) .504/.509 lift with 1.6 roller rocker arms. The cam looks allright but I don't know if I should reuse it are buy new cam and lifters. It did check a couple of the rod bearings and they looked good. This is not a matching # motor, but I am trying to get it ready for the GSX reunion. Next week I will try to get the old bearings out and new installed. The heads, crank and pistons are still in/on the block. I does look like the rotating assembly is balanced! Any Comments or suggestions welcome. Don Terhune
I think now is a good time to install T/A's Dual feed/ dual groove cam bearings. Also, since you're already there, I think a new cam and lifters is cheap insurance that you won't have to open it back up for the same problem. -Josh
From my experience with engine problems over the years, I would take the time to look at things closely as cam bearing failures do not just "happen". They usually occurr from too much oil pump load caused by high volume oil pumps with larger pump gears or a valve train interference condition. The latter would be caused by valve spring coil bind, retainer to valve guide interference or a long-shot such as pushrods bottoming out hydraulic lifter plungers. Take the time to look at everything closely, if you just install new cam bearings you may be taking it apart again!
The car came with a high volume oil pump on it. I called T/A to see if I had to remove the heads and rotating assembly, Mike said I might be able to replace the bearings with everything still together. I did have to use a pry bar to get the cam out. It pulled the 1st bearing out with the cam, the other bearing are still in the block. I hope the 1st cam journal is OK. Make said the HVoil pump caused this. Don PS I don't know if this motor was built by a buick guy or not.
You should probably also check the oil galley plugs on the front of the block as they could be installed too deep...cutting off or restricting the oil flow. I saw a Buick 350 that had press in front oil galley plugs...they were pressed in too far and cut off some or all the oil flow. The result was what you mention...the cam bearings were flattening out and squeezing outwards so it looked like large melted cam bearing "flakes" sticking out around the perimeter of the bearings. Even screw-in plugs can cause a problem if the plugs are too thick or in too deep.
I had a HV pump make junk out of the front cam bearing. All the rest of the cam bearings looked ok. The pin holding the distributor gear to distributor shaft was also worn (starting to shear). Swap out the HV pump. If everything looks good, I would replace the front cam bearing only :eek2: , and install a booster plate and pump and put the X back on the road.
I'd recommend you check the size of your cam bearing bores. The ones on my 340 block were badly undersized, meaning that when the cam bearings were installed they were too tight and the cam would not go in at all. Believe it or not, this isn't at all uncommon and is often resolved by taking a scraper to the bearing material, a less than optimum solution. How does this happen? Simple, the tooling originally used to machine the block wears down gradually, resulting in undersized bores. If the operator does not check the size frequently enough and make adjustments, tight bores go out the door. There's even been some speculation that Buick simply fit the bearings to the random sized bores and then finish reamed or honed the inserts to size, but nobody seems to know for sure. Better to check 'em. If they're undersized you might be able to have the shells polished or turned to compensate. Jim
This morning I seperated the body from the frame. I will probably go ahead and remove the heads, pistons and crank just to check everything over since it is this far apart. I don't know what pistons are in it, thats another reason to strip it on down. Any suggestions on a cam? The heads looked to be polished and have big valves,B4B intake, Roller rockers, AC, PS, PB, Auto (was 400, might be 2004R) 3.42 gears. Thanks alot Don
