The Stovebolt Site Forums The Shop Area Engine Shop 235 rocker shaft oiling

I primed the oil pump last night in my 235, the tube on the rocke shaft had a leak in it where the top loop is, is this supposed to be there? If not how can I fix it, preferably on the vehicle? Is it OK with the hole even if it's not supposed to be their, I got oil to all rockers but it seemed slow getting to the front two. Thanks.

Does your oil feedpipe to the rocker arms loop over the shaft and dump excess oil onto the top of the head? If so, then there is a little hole that dumps oil directly down onto the brass center section. That is normal, as long as all rockers get oil.

chip

Yes, it loops over and dumps oil onto the head, but on the underside of the top loop oil dumps onto the center section like you described. I guess it was clogged before I rebuilt my engine so I never noticed it before.

I believe that hole is there to prevent the oil from being siphoned out of the rocker shaft when shut down.

I am doing some head work right now and was looking at my tube. It doesn't look like it does in my manual. The manual sounds more like what you guys describe. Mine comes straight up and above the rocker shaft it's squeezed closed. No loop over the rocker shaft.

Tony, Guys would do that to ensure enough oil to the rockers, when the little holes in the shaft get plugged, you need more pressure to get through, so the overflow is pinced to provide full pressure.

The tube on my 62 235 are the same way.

*Thinks* Ya know thats funny...

My '60 235 motor had the pinched off looking feedpipe. I thought at the time that it was factory-done.... This motor was a bone-stocker with 1/2 inch of goo stuck to all internal parts and walls.

Tony M, aren't you the one with a '56 head on a '54 block? Maybe the guy carried the later-model feedpipe over with the head swap??? Any signs of improper oiling or other rocker assembly damage?

chip

Chev made a major change in the way the rockers are oiled in 1959. Up to 58 the oil was supplied from the rear cam bearing through a 1/16" restricting fitting, then through a steel tube, then up around the head bolt, then to the oil distirbutor fitting between the two shafts which has the loop up and over like you have been talking about.
Starting in 59 chev changed to a pressure oiling system where oil was supplied from the lifter oil gally straight up a new cast-in rocker supply gally in the center of the block, up to the same head bolt as before where a new larger 11/32" orifice is used, and then to the oil distributor fitting between the rockers. The oil distributor is pinched off with no loop over the top. The rockers were also changed. The oil groove on the inside was moved 1/4" off center so the oil hole in the shaft was not lined up with the groove so as to pressurize the whole system.
Sometimes the early oil distributors were pinched off to help oiling but not from the factory.

Chip, the rocker assembly seems to be in very good shape. No slop or anything. I am wondering if it was changed with the head. Things were real gummy and dirty in there but I saw no evidence of heat or excessive wear. When I put it back together I will see how the oiling works up there before I close it all back up. I think this head has not been on there long.