DANIEL TINDER (2/28/2008)
Ted, Could you elaborate re: your reasoning for NOT pressurizing the shafts? (In my case, I was always afraid that oil would flood the valves if not directed straight down the pushrod/drain holes).By not blocking the oil outlet tubes, air is purged from the shafts thereby insuring that the shaft stays full of oil. If these tubes are blocked, then the potential is there for air to be trapped within the shafts. A constant flow of oil through the shafts by the use of the overflow tubes will purge the air and help to carry off some of the heat rather than the oil potentially stagnating and then sludging up. On a solid lifter engine such as the Y, the rockers get to relax between valve actions which promotes additional leakage at the bottom of the rocker but on a hydraulic cammed engine such as the FE, that period of relaxation doesn’t occur and this is where pressure oiling would have some additional benefit. But as John also brought up, allowing the excess oil to bleed off at the overflow tubes also insures that the oil level in the heads does not exceed the ability of the drain holes to carry it away.John F (2/28/2008)
This may be a dumb question but, what are you using to restrict the oil flow into the rocker shafts?
To restrict the oil to the rockers themselves, I thread the ‘second from the right’ pedestal at its bottom with a 5/16 X 18 tap and install a set screw that is drilled with the appropriately sized hole. This could be done in the head as an alternate choice. An Fe is already sized at 0.125” in the head gasket but the Y is pretty liberal in its oiling up to the rockers if the restriction at the camshaft is freed up. Not counting the restriction in the oiling at the camshaft, the Y has a 5/16” hole in the block with a corresponding 5/16” hole in the head gasket. The oil passageway in the cylinder head downsizes to a ¼”and this size is maintained up to the rocker arm shaft. If the oil is freed up at the camshaft, then that’s a lot of oil flow to contend with.Another rocker shaft modification would be to grind some angled slots across the lower oiling holes to promote more oil across the inside wear area of the rocker arm. There’s a picture of this modification elsewhere in the forums.
Davis (2/28/2008)
but then FE's do have oil baffles under the shafts..
The oil shields or baffles under the rockers are another story. This would appear to be another item on the Y that was dropped as a cost cutting measure early on but I do prefer to run them when given the option. If running a positive seal on the valve guide, then the baffles are likely not worth much but if running the stock unbrella type of seal, then these shields do reduce the amount of oil getting to the guide.
Lorena, Texas (South of Waco)