The cam in my new 300 rebuild is too tight. Does anyone have any tips to free it up? I tried two sets of bearings. The cam is a Comp 260. The stock cam that came out of it is very snug, but i can't get the Comp cam past the second bearing. There doesn't appear to be any burrs on the bearings. I scuffed the cam journals and the cam bearings with Scotch-Brit. Didn't help. What does a machine shop do to solve this problem? Any tips would be greatly appreciated. Thanks,...jack

 

to test fit the bearings on the cam before install?...I know there are different od's for cam bearings for different years..is your block a 77? I've had my machine guy install cam bearings lately, he mentioned the different bearings..and each bearing has it's "spot"?

Assuming all of that is kewl...this search has brought up other's issues

https://www.ford-trucks.com/forums/1...d-answers.html

F250 restorer provides the official ford info on the bore change...

https://www.ford-trucks.com/forums/9...-bearings.html

I don't have the necessary tool to install my own so I have it done, but I can appreciate being sure it is done right..I have witnessed bearings being "emory polished" some to facilitate shaft install...you didn't hear it from me.

 

Block is D5TE-6015AA. Bearings are Perfect Circle SH-567S

 

I'm sorry to hear that. It is very worrisome. I had that problem with a block. My mechanic gently worked the problem bearing with fine emery cloth or w/d sand paper. That freaked me out so I took the block to the machine shop and he removed it, then did the same thing with a new bearing.

Journal sizes did change over the years, so make sure your bearings are for the year of your block. I posted the years and sizes in another thread. Good luck. k

P.S. You did lube the cam journals well before sliding it it, right?

 

how this goes. I'm in the process of installing a used/broke in cam with matching lifters in a fresh honed block (with new cam bearings) from the machine shop. In a perfect world, everything would fit just perfect...but that block is old, and that cam is lllooonnngggg...we'll see how my guy did with his cam bearing install... when I put in the cam...of course it IS used..and "broken in"

I know it's a stock cam..but it IS looking good..and I WILL advance it 4 degrees with the Cloyes alum/steel gear set.

 

I thought this might help.

4.9L CAM BEARING HOUSING BORE CHANGE
Revised Cam Bearing housing Bore On
1985-87 Ford 300 CID (4.9L) Engines
The Form Motor Company has revised the cam bearing housing bore on
Ford 300 CID (4.9L) engines manufactured after June 4th, 1985.
Previously all four housing bores measured 2.1440. The late style
block with the casting number E1TE-6015AA, has the following cam
bearing housing bore dimensions:
Location Part # Bore Diameter
1 E5TZ-6261A 2.1590
2 E5TZ-6262A 2.1440
3 E5TZ-6262A 2.1440
4 E5TZ-6261A 2.1590

AERA members are cautioned to check each cylinder block's cam
bearing housing bore for positive identification.

At this time the revised design cam bearings are available only
through Ford Motor Company. They will be made available through the
aftermarket during the 4th quarter of 1987.

 

Remember the cam was too tight? Cam is a Comp 260. I sent it back to Comp. They couldn't (or wouldn't) tell me much, but they did admit the journals were a bit big. About .001-.0015 too big by my measurements. They sent the cam back - or sent me another one. This one fits nice. I am happy. I haven't had much good luck with their products, The last time i used a Comp cam and lifters, i got a bad set of lifters. Replaced with Ford lifters to solve that problem. At least they fixed this problem for me. Thanks to you guys for your interest and advice. Thought you might be interested in the solution...jack

 

u-go-man...