The Stovebolt Site Forums The Shop Area Engine Shop '56 265 rear cam journal - groove or no groove?

Helping a friend go thru an engine that needs everything. Bought cam/lifter kit and cam bearings. The new cam does not have the groove on rear journal, and the new cam brgs have a narrow brg with one hole for the rear journal, not a wider brg with two holes like the original. I'm told I have to send cam stuff back and get new cam & brgs that match the old, or cut a groove in new cam to match the old. Since the old rear cam brg was in good enough shape to reuse, I thought I would just drill out the material between the two holes of old brg creating a slot so I could use the new grooveless cam. However, the machine shop I contacted for advice said the slot idea will not work and must groove the cam. If the cam journal groove allows oil to get from one hole to the next, why wouldn't the slot idea do the same thing when used in conjunction with a grooveless cam?

I worked on a 265 a few years back, and in that case I has the two hole rear bearing.
In my case I used my dremel tool and cut a shallow path on the back side of the bearing between the two holes for the oil to pass.
It worked well.
Later engines have a groove in the block to connect the holes, so making a path on the back side of the bearing shell basically does the same thing.

Any machinist with a lathe and half a brain can cut a groove in the new cam. Be sure to use a cutter bit with a radius on the nose of the tool to prevent making square corners at the bottom of the groove. Supplying enough oil volume to keep the lifters pumped up might be difficult without a groove to supply constant pressure and a wide enough channel for sufficient oil flow. You'll still need to "connect the dots" on the bearing to allow oil to flow to one bank of lifters. I'd be concerned about the narrow rear bearing maybe exposing oil passages that the wider one would cover.
Jerry

I did reuse the old, wider rear cam bearing as it wasn't beat up like the rest of them. I think the engine was either overheated or run low on oil as there was melted babbit throughout the engine oil passages (mains, rods, cam bearings all gone except rear cam brg). What I did was to create a slot between the two oil holes in the rear cam bearing and made sure it lined up with the small hole in the block next to the groove already cut in the block which the wider rear cam bearing covers when installed. The old cam had a slot in the rear journal which only went 1/4 of the way around the circumference. This would allow oil to pass from one hole to the next only when the slot uncovered the two holes. By slotting the rear cam bearing, oil should be allowed passage between the block groove and the block hole 100% of the time to feed lifters even with an ungrooved/slotted rear cam journal. I fail to see why this wouldn't work as I've been told by some. Can you explain why the slotted rear cam bearing used in conjunction with a modern ungrooved cam won't work? My only other reply to date said he did something similar way back when and it seemed to work out ok.

In my case I did more than cut a shallow groove on the back side of the bearing. I actually removed all the material between the two holes to create a slot. My theory is oil should now be allowed to flow 100% of the time instead of only 25% of the time as the old cam had a groove cut just 1/4 of the way around the circumference. Maybe that was the engine's oiling problem in the first place as I found melted babbitt throughout the engine's oil galleys with all the bearings gone except the rear cam bearing which I reused.

Your method will work fine, and an easy fix.

Another anomaly on some 265 engines is that there is only one position for the distributor housing. Instead of having a groove all the way around the housing that aligns with the lifter bores, the early distributor had a flat spot which had to be clocked correctly. If the housing was installed wrong and the plug wires moved to compensate, oil flow to one bank of lifters was restricted or shut off entirely.
Jerry

I did not know that, so I will check into it. Currently the '56 I'll be putting this engine into has a 70's era 350 installed by the previous owner, but they used the original '56 distributor. Since there are no oiling problems, either the distributor is grooved all the way around or they indexed it properly. I'll take a closer look when I pull the 350 and remove the old distributor as I'm planning to put the '56 distributor into the '56 265. Thank you for that information.

Dave