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For TECH Guys - Just Posted Today @ y-blocksforever.com


SOURCE - http://forums.y-blocksforever.com/Topic153967.aspx

Ted - Co-Admistrator - y-blocksforever.com

Here are some more thoughts on the subject.

A major difference between the FE engines and the Ford Y is that the FE engines had hydraulic lifters while the Y had solids. I am excluding the 406 and 427 Fords from this discussion. With hydraulic lifters, the rockers are loaded against the shaft at all times which means there is no period of relaxation of the rocker to the shaft. In this instance a pressurized rocker shaft will force oil in those locations that normally would not get it. The Ford Y on the other hand does have that period of relaxation of the rockers to the shafts and simply relies on gravity to feed oil to the bottom of the shafts. The overflow tubes do allow the shafts to stay full of oil thus eliminating air pockets while at the same time allows the flow of oil through the shafts to be increased thus carrying away the excess heat generated there. Another plus to the overflow tubes is the right side of engine tube providing additional oil to the timing chain set that it would not receiver otherwise. The oil trough on the early engines worked in tandem with the oil flow tubes to insure that the oil did indeed get on the chain.

As already mentioned, the root of the Ford Y top end oiling problems was with the use paraffin based oils of the time. The Y was designed originally for the modern multi-weight oils that were introduced at the same time as the Y but not all owners saw fit to use those oils from the onset. I do still see Ford Y engines with 300K miles with the overflow tubes still intact and these engines are still providing oil to the rockers. These high mileage engines all run a good quality oil which is routinely changed.

A big fail point on engines being rebuilt now is with the softer than stock cam bearings that are being used. The cam bearings end up wearing much quicker to the point that the groove in the center journal of the camshaft journal is pushed into the bearing thus either restricting the oil flow to the top or shutting it off completely. Part of this accelerated wear comes from using valve spring pressures that are now much higher than stock. Common fixes for this are using a center camshaft bearing that has a groove machined on the back side of it, cutting the groove in the center camshaft journal deeper, or machining a groove in the center cam bearing hole in the block that allows the three holes there to be connected thus eliminating the need for the groove in the camshaft. A recent cam bearing for the Y from Engine Tech (made in South America) is made from a harder material and has thus far helped considerably in stopping the aforementioned problems associated with the softer cam bearing material.

For stock engines, I use the overflow tubes. For performance applications where the valve spring pressures are increased, I will convert the shafts to a pressurized system. All the Harland Sharp roller rocker arm assemblies I prepare are set up for pressurized oiling as these use bronze bushings within the rockers which are prone to galling if they starve for oil.


Lorena, Texas (South of Waco)

Now this 'ol boy (Ted Eaton ... not me) is smart and experienced. I pale by comparison, I have nowhere near this man's knowledge and experience.

There is much hidden knowledge (in past threads there) that fully explains the deficences of the FYB valve-train. It is fascinating reading.