312 cam bearing installlation


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By MarkMontereyBay - 14 Years Ago
I have the 312 on an engine stand. The cylinders, mains and rod bearings/journals all check out; cylinders are standard bore with newer pistons, rings, etc. The engine has less than 20k on the previous owners rebuild. What doesn't look good are the cam bearings. A new Mummert 270 is ready to go in and I want to replace the cam bearings using a Proform cam bearing remover/installer. I really don't want to remove all the pistons/rods and reinstall them if possible. The old cam lobes look good but the journals are scuffed and the lifters cam out easily using a magnet. I can't see a good way to get this done with the rotating assembly in place. Do I bite the bullet and take the internals out? Thanks.
By Pete 55Tbird - 14 Years Ago
Mark,

First I envy you for living in Monterey. We just came back from there this Friday and the weather was perfect. As to your cam and lifter removal, can`t you just rotate the engine on the stand and let the lifters fall out of the way so you can then remove the cam, then remove the lifters, cam bearings etc? Then its just a matter of putting it all back in. Pete

PS wooden clothes pins will hold the lifters up if you want the engine upright.

By MarkMontereyBay - 14 Years Ago
Yes, the weather has turned warm and clear here. Beaches will be filling up soon enough with visitors. We are across the Bay from the city of Monterey in Rio Del Mar nearer Santa Cruz.

I have the cam and lifters out. I just flipped the motor upside down and pulled the cam. Then took the lifters out one by one to keep them in order. I need to figure out how to get the cam bearings in/out with the crank and rods still in the block.


By mctim64 - 14 Years Ago
If you are careful you should have no trouble changing the bearings with the internals in place, you will have to rotate the engine to get room to do each one but it is doable.  I have a bearing driver that is solid and made to fit Y cam bearings, if yours is adjustable it may be a little more difficult.  Good luck!
By lowrider - 14 Years Ago
I would do what Tim suggested and get a soild driver for the cam bearings. I buggered up a bearing recently using one of those adjustable bearing drivers. I was lucky and found a bearing locally and "learned" about those drivers through experience.
By MarkMontereyBay - 14 Years Ago
After eyeballing the block with the rotating assembly in place and the ever present Murphy's Law, I took the pistons/rods out yesterday and will lift the crank today. With a better look, the cam bearings appear scarred up from previous cam installation/removal. This is the cam bearing tool I have.

http://www.summitracing.com/parts/PRO-66820/?rtype=10

Have never used it. Been in my tool hoardings for years. So I think getting the crank/rods out will minimize me screwing up 50+ bucks worth of cam bearings and end up taking it all apart anyway.
By MarkMontereyBay - 14 Years Ago
The cam bearings, cam and lifters are installed. Used Isky RevLube 2000. Had an issue with one of the new lifters binding in the bore. Looked it over, cleaned everything, re-lubed and tried several times....still sticking about halfway in. Called J. Mummert to see if he had any advice. Ended up playing musical chairs with the lifters until they all found slippery homes. Using Mititoyo digital calipers my original lifters measured .4880, the new ones measured .4890.



Typo corrections..the lifter diameters are .4980 and .4990