Cam Bearings

[daveymc29]

My understanding is that the stock block has no "bearings" as most of us think of a bearing. Doesn't the cam just ride inside an opening in the cast iron block? I have talked with someone in the know, and I can't name him because I have forgotten who it was, but he had built or had built for him, many A engines. One had badly worn cam "holes"so he had the builder ream the openings enough to insert some type, I believe bronze, bearing material . He told me that was the best running engine he had ever had. very smooth.
On a trip to TX from CA a gentleman drove past me on a hill out of Albuquerque and I asked him what he had in his car later. He told me it is balanced to zero, no 2/10 of a gram like most shop profess to be the limit. No other mods and he nada heavier car than mine, and two people in it. Any thoughts appreciated.

 

[Charlie Stephens]

You can also buy cams with oversize bearings from Bill Stipe stipemachine.com, stipemci@excel.net, (920) 467-9700. In addition to solving the bearing problem I have heard that his cams are excellent.

Charlie Stephens

 

[tudoor]

I have one of Bills cams and it works great. I bought the one with the cam bearings were 5tho over and had the block cam surface turned to fit the cam.

 

[tbirdtbird]

he has more under the hood than just better cam bearings.....more than a rabbit's foot, too...

 

[Purdy Swoft]

Pete that posts here is doing a regrind cam with sleeved oversize bearings I believe.

 

[Pete]

Pete that posts here is doing a regrind cam with sleeved oversize bearings I believe.

Center journal only. Std. size only.

 

[Chuck Sea/Tac]

If you can find a shop with the right size line bore machine, the cam line can be bored out and early pinto bearings can be installed. The two in the center have to be eyebrowed for the oil and distributor gear.

 

[MikeK]

Here's one of mine. If you simply bore oversize for an oversized cam you have a white elephant- a block that can only accept expensive custom cams, and virtually no resale market if you want to sell one of those cams.

As far as 0.0g vs 0.2g balance, the difference in a low speed engine will be well below perception. If you were balancing a 50,000rpm turbine it would matter.

Other factors, like uneven spark timing variances, crank indexing (throws not 180.000 degrees apart), crank rotational distortion from harmonics, and cam lobe indexing errors between the four pairs of lobes during manufacture or regrind, and uneven fuel charge distribution through the very primitive intake system all contribute to vibration.

At various time points minor imbalances become additive, like in music when you can hear a slightly off-tune 'beating', or if you play the fifth with a given note, halving the resultant frequency and doubling the amplitude.

 

[Purdy Swoft]

Good music lesson!!!

 

[Bruce of MN]

if you play the fifth

Or drink a fifth.