Cam bearings

the different sizes are attributed to the assembly process. In most engine assemblies from the manufactures, a complete set of cam bearings are placed on a stepped mandrel and driven in to the block all at once. this makes assembly easy as all bearings go in with one stroke.

Several engines used cam bearing of different sizes altho it was very prevalent on many crankshafts of older cars. It was probably done to facilitate the boring bar problems of that time.

About the camshaft cages used on the Lycoming engine, the older Oakland V-8 of 1930 & 1931 along with the Pontiac V-8 of 1932 used them and I believe the Cadillac?s V-8 from 1914 to 1935. The Oldsmobile Viking of 193? wasn't an easy one either, altho the Viking engine seems to have the camshaft comes out the front.

The procedure starts out on the Viking by removing the hood, radiator, timing chain cover and timing chain and 17 more steps to take it out and to put it back in the car not much different from old Ford V-8.

M. L. Anderson

When I had my s/c block rebuilt (printed?) by Jim Oddy, I supplied him with a set of new cam bearings. When I checked with him after a week or so, he informed me that one of the cam bearings was way too loose and therefore unuseable. I felt panic! Where am I going to find another new bearing? He told me not to panic, he had already put a new one in! It was a standard bearing! I don't know what it was from, but whatever he used, the engine still runs beautifully, with wonderful oil pressure etc. Sometimes you can be too smart! A good engine rebuilder may know a lot more than an enthusiastic amateur. Ric.

I would assume that since the bearings are progressive in size, this would allow easier cam installation. I am working on two standard engines and found the cam installation very easy. Wish I could say the same for the rocker installation. There are some modern engines that use this design.

I am having a S/C engine rebuilt by George Arakelian. Upon tear down of the engine, George discovered that it had bronze cam bearings installed in it which one of them had seized. George ask if I could locate a set of originals that we could send out to be rebabitted. I gave my good friend Pete Kelly a call and with a quick trip to Canada, we had a set of used cam bearings. George informed me that of the five cam bearing used in the 810/12 Cord engines, there are four different sizes bearings used. I ask George 'Why did Lycoming do that'? George's reply was, 'Dammed if I know'!
The question is, 'Why did Lycoming use four different sizes cam bearings in the Cord 810/12 standard and S/C engines'? George has rebuilt several engines, both standard and S/C and all of them had multiple size cam beargings. There must be a logical reason for this and I am looking forward to hearing the responses.

Al Hatch