Distributor hole still leaking (pouring)

This is my second post on this - a year later. On my 304, oil runs out of the hole in the timing cover where the distributor shaft goes in. The volume is such that I thought I had a crankcase pressure problem, but I've got a new pcv valve in and my manifold vacuum going to the pcv valve is strong. This is not a slow leak. I can clean off the lake on top of the timing cover, start the engine cold, and within fifteen minutes I've got a new lake. I'm going to put another new gasket on today. ANY OTHER IDEAS?? Thanks.

 

Are you sure that the distributor shaft is not bottoming out on the oil pump gear shaft? If it is, then the distributor may not be fully seated onto the timing cover.

Does the distributor shaft fit the bore of the timing cover well....no wobbling side-to-side?

Rich

 

I don't know the innards of the timing cover. Does the dist shaft pass through the same cavity as the timing chain? Or is it its own wealed cavity leading to the oil pump shaft? The reason I'm asking is that I wonder if the entire timing chain cavity is getting flooded and pressurized. Is something blocking a drain passage? But if they are separate cavities the dist hole could fill without filling the timing chain cavity. Original distributer?

 

The distributor gear keys into the end of the oil pump shaft, and oil could find its way under pressure to that connection. However, the gear is open to the timing chain cavity, so I would expect that oil to drain into the timing cover and back to the pan somehow. I don't have a block in front of me, so I can't see how oil gets back to the pan from the timing cover. There is a steady stream of oil going into the timing cover, however. Timing chain and distributor gear oiling comes from a passage in the end of the cam. Oil is picked up from the front cam bearing and drains out the front of the cam gear. From there it gets flung everywhere inside the timing cover, lubricating the fuel pump eccentric, distributor gears, and timing chain and gears.

It's possible that somehow you have plugged the drain from the timing cover, preventing the oil entering from the cam end from exiting the timing cover. That oil is under pressure, and if it fills the cavity, the distributor shaft seems the likely place it would exit. There's no seal on the distributor shaft that I can see - no gasket and no o-rings on the shaft. Normally it would not leak because the splash oiling from the cam gear would drain back to the pan by gravity. Any oil splashed on the exposed part of the distributor would also drain back - oil would have to run uphill, or be under pressure, to exit from the base of the distributor. The distributor is a tight fit in the bore, so it might take a while for significant oil to be forced out under pressure...

What's the history here? New timing cover? What repairs?

 

Thanks for the thoughtful replies. I pulled the timing cover and polished the mating surface where the machined lip on the distributor shaft meets the timing cover. Also worked on the distributor hold-down bracket to make sure getting even pressure down on the shaft - the guy who modified the bracket when the HEI was installed may not have taken the time to do that. So far no more leaking.