I got a 80,000 mile or so long block that I am swapping into my car. The stock cam was somewhat stubborn to remove. But my cam from my motor that I am swapping over will not go in to the new motor at all. Goes through journal 1 fine, but locks up solid halfway into journal 2. I can put the stock cam from the newly acquired motor into my old motor fine, and my cam still goes into my old motor just fine. I can get the stock cam back into the new motor, but it is a bit snug going through journal number 2. Shoud I bother with new cam bearings, turn the cam journals down, or do I need to get the cam journals in the block line honed?
Why not just mic the journals and get the numbers. I would compare that to the id measurement of the journals. I would buy new grooved cam bearings from TA and have no future worries.
One of those bearings may not have been in there straight to start out with. not sure how the other cam even went in. If I where you. i would just take this as an oporunity to put n some new cam bearings. you get them in straight and i bet your problem will be solved.
Just food for thought on grooved cam bearings. I lost two motors in a short period of time due to melted down grooved cam bearings that clogged the oil holes. This cost me thousands of dollars. It remains to be seen whether or not shoddy machine work by a formerly reputable Buick machine shop caused this or the grooved bearings. I had an old time buick mechanic tell me not to use grooved as buick cam bearing do not have enough surface to support grooves. They might be Ok for a race car that sees limited idling but not for a street car. Be real careful about cam bearing clearance as it is critical. It is a better idea to modify your block for proper oiling. I will never used grooved again I don't care if they put 8 grooves in them!$$$$$$$$$$$$
More grooves in the bearing just makes it weaker. A half-circle groove in the block where there is minimal loading is a better idea.
Nicholas, That cam must spin freely! I have used the grooved bearings on almost all engine builds and have had a few scenerios happen: 1. Not put in square. Caused the cam to be tight on that bearing. 2. Nick on bearing surface. Caused from installer not being careful on installing bearing. 3. Nick or dent in cam. Poor handling of cam during shipping, storage. 4. Not using a light oil to check for spin/fit issues. 5. Bent camshaft. I would check for nicks on all surfaces, look closely for dents, out of rounds, both on the cam and bearing surfaces. Try another cam besides the stock one. I have even had to take a camshaft in and have it slightly polished on the cam surfaces to spin just right. Although that was only once, they should fit fine from the grinder.
Talked to Dave at TA and ordered new new cam bearings yesterday. I will let y'all know on Saturday if that solves the problem.
I'd have that camshaft carefully measure for : Journal diameter, journal taper, and the whole shaft checked for straightness. Any decent machinist can do this for you.
I used to assemble engines in a machine shop before I had to go on disability. I found that most of the time if a cam was tight it was because the a bearing was not in straight. I learned to do the front and back bearing different than I was showed how to install them. Maybe others that do allot of them figured this out also but it saves allot of headaches. I was shown to drive the front bearing in from the front and the back one from the rear, which don't give you anything to square up the bearing decent. What I started doing was I would file the sharp corner off the inside edge of the front and rear cam bearing bores in the block and then I would slide the bearing driver in from the back of the block to the front and stick the bearing on the tool from inside the block and drive it in from the back so I can use the centering cone in the back bearing hole to square up the front bearing, then just turn things around for the rear bearing and drive it in from the front hole, again so I can use the centering cone in the front hole to line up the back bearing. I hope I explained this well enough to understand what I mean. I am sure anyone who has installed cam bearings before will get what I mean. Maybe all the better shops do it this way, I don't know. It made so much sence to my shop boss he started to install cam bearings the same way. It cut way down on having to shave bearings to make the cams fit. :Smarty: :beer
I'm certain that the cam is not the problem. It slides in and out of the old '74 motor just fine, in which it has about 10,000 trouble-free miles. Of course, if I HAD mics I'd be micing all of this. :error: I am using the cam bearing tool that was described on the BuickPerformance list and TimR's website. I always use one tool to drive the bearing and a second tool on the shaft for support, and drive the bearing in by turning a nut on the 1/2" threaded rod that the tools go on. I was not even aware that the block was chamfered for the bearings to go in one way or the other. The bearings are chamfered anyway, so I have never had a problem installing the front or rear bearings from "inside" the engine.
