Stock type cam bearing with a groove on the back of the bearing for oil.
***The performance cam bearing is a harder bearing for big spring pressures that some large lift cams may require.***
The grooved cam bearing has 3 purposes. (1) is these are the same as the ole Moroso restrictor kit. The groove on the backside does the restriction. Controlling the oil flow to the cam bearing keeps more oil in the pan. (2) All shafts that turn in oil developed a hydrodynamic wedge. Clocking the oil hole in the 3:00-4:00 position feeds oil at the wedge so less oil is wasted. (3) Camshaft/valve spring pressure push cam near straight down. If you ever look at old cam bearings, you see wear in the 7:00-5:00 position. By clocking the bearing, the oil hole is now out of the way, giving %100 bearing material. making the lbs per sq inch less.
Because of manufacturing processes, the horizontal oil line you see upfront intersects the main to cam galley. The 2nd galley the manufacturer drills for the purpose of routing oil to the passenger side galley. By default, this 2nd line also starts at the 1st main. Issues we saw was the #1 main was seeing oil flow 2 times, and the 2nd time is a much larger galley. The bottom line is, when we had engines on our SimTest, we saw #1 main flowing oil like crazy. The reason for blocking the galley in #1 is to even out the oil flow. “The oiling system is a system of leaks, and those leaks are needed. We just need to control the amount”