tomshobby said:
Randall, didn't the TR3's have a vent off the side of the block and down towards the ground?
Yup. But since it's directly from the crankcase, it's not affected by all that oil spraying around inside the rocker cover. And since it's not connected to the intake manifold, it's not considered "positive" crankcase ventilation.
Horrible from an environmental point of view, I'll probably rig a proper PCV system for my next TR.
'Normal' oil circulation for the rocker shaft is that the shaft slowly fills with oil, which then dribbles out through the rocker bushings and the hole on top. From there, it runs down the rocker to lube the rest of the valve train. Because of the slow oil movement, it is easy for the passage to the shaft and the shaft itself to fill with sludge over time, which can eventually block oil flow. (I've actually never seen this on my engines, since I stopped using oils that form sludge, but I've seen it on other people's engines.) So sometimes, after setting the valves, I start the engine with the cover off and watch to see that the hole in the #1 rocker (farthest from the oil feed) fills with oil within a minute or so.
But the external oil feed puts full gallery pressure into the rocker shaft, resulting in a huge flow of oil through there. It literally painted the underside of the hood when I started the engine !
BTW, that engine came to me with the feed blocked and I had already installed it when I discovered the problem. Didn't feel like pulling it again just to correct that (since I fully intended to install a properly rebuilt engine within a year or two anyway), hence the band-aid. Never did get around to properly building an engine; that same block is in the car today (with different pistons obviously).