The Stovebolt Site Forums The Shop Area Engine Shop 216 valve oiling

Gentlemen,

Some background- My first car was a '38 Chev back when a kid could afford one for a first car, followed by a '49 convert, then a 61 (6) station wagon. Had the heads off all of them and set the valves as required. Now, I've got a '50 1/2 ton pickup and, honestly, don't recall what the inside of the rocker cover should look like. Seems to me that there should be oil all over the place, with puddles in the valve retainers and pushrod cups. What I see with this one is oil oozing very slowly out of the rocker holes, and oil in the pushrod cups. Valve retainers seem dry. I've loosened the line to the rocker shaft and oil comes out (no flood).

Does this sound normal or should I pull the rocker shaft? I've had the pickup for a while and it is a monthly driver that I'd like to make daily.

Thanks, Bill

Bill,

What you nicely describe seems like your engine has adequate lubrication of the rocker arms and around the lifters.

If you want to take the rocker-arm asembly off and clean the insides and holes on the two rocker-arm bars, you will then be certain that it is clear/clean inside, end-to-end.

If you have a low-pressure 235 or a 216, do not expect high pressure (and/or high oil flow) through the assembly. If oil is reaching each rocker-arm and each lifter, it is OK. These engines had an oil-fliow divider/diverter/distributor-valve behind/under the middle of the exhaust manifold. Many Shop Manuals have a drawing of this part of the engine lubrication system.

Soon after the high pressure 235s (and 261s) came out, GM drilled the block so that oil also reached the lifters directly through a journal in the block (assuring enough oil for hydraulic lifters).

You're working on the wrong end of the system. Try to get the oil distributor removed and give it a good cleaning, followed by flushing the through-the-block oil line with carburetor cleaner. The oil distributor restricts oil flow to the head until the lower end bearings get at least 15 pounds of pressure. If you're dealing with a tired engine with sloppy lower end clearances, there will be little, if any oil flow to the head, especially at idle. Once the engine speed comes up out on the road and the oil pressure rises, there will be more oil flow to the head.
Jerry

Thanks for the replies. Guess my concern comes from not seeing the valve spring caps wet and allowing stem and guide oiling. I had hoped not to have to attack the oil distributor or pull the rocker shafts, but will if some road travel does not show more oil in the rocker box.

Did notice that at fast idle there was a steady drip from the open tube leading down from the oil connector casting to the center oil drainback hole in the head.

The engine is a Forberg rebuild of about 25 years ago with about 10k miles on it. No sludge or funny noises and compression, warm, plugs out and open throttle is just under 120 PSI +/- about 2 pounds.. Idle vacuum (800 feet above S.L.) is a steady 20 inches. Only complaint is popping thru the carb on fast throttle up- one pop per push, but its a big one if the push is fast. (Looks like a good squirt from the pump but???)

Bill

If there is oil flow out of the overflow tube then it doesn't sound like anything is wrong. Only a small flow out of the vent holes on each rocker is correct.
Chevrolet never sent much oil towards the valve end of the rockers. At higher RPM's some oil mist does find the valve stems.
In fact 1932 was the first year they put the vent hole on top of each rocker. Before that they only sent oil to the pushrod socket through a felt wick.

Pop through the carb might be a vacuum advance proplem. Sometimes they go bad.

Late ignition timing and/or poor accelerator pump performance can result in a backfire on quick throttle movement. Alcohol-added gas is rough on accelerator pump plungers.
Jerry

You don't want more than a dribble out of the holes in the rocker arms at idle. If you have any more than that, you will have too much oil in the top end which will end up getting sucked into the valve guides.

The bottom end of my 49 216 is nearing the end of it's serviceable life w/an estimated 119K miles on it. The head was totally rebuilt with approximately 19k miles on it.
Gauge oil pressure at operating temp at most all rpm is 7-8 psi. 12-13 psi when cold.
The oil line from the oil distributor to the head was replaced and the valve train fully cleaned out.
It can take 1 to 2 minutes before I see oil weeping out of the rocker arm holes but i get a good steady stream of oil out of the rocker shaft center connector directed back down into the engine. Once warmed up I get a good continual flow of oil to the rockers, so much so that I have been unable to completely stop the various oil leaks I get from the valve cover gasket, especially at the back side (the lowest spot in the head).
The head drains very well so theres very little residual oil left in the head after shutdown.
This has been pretty consistent for 19k miles.
If yours is similar your GTG. if your oil pressure is higher your very GTG LOL.

Should one re-check/adjust valve lash after removing rocker shaft for cleaning? This project is on the list for this weekend.

Don't see why anything would change, but I probably would anyway just because I'm paranoid.

Yes.

You might as well retorque the head bolts, install the rocker arm assembly, start the engine and warm it up for 30 minutes.

Then, turn off the engine and adjust the valves. There is a procedure in the Tech Tips (similar to this valve lash adjustment procedure).

Re-torque head bolts?

There is no absolute need to re-torque the head bolts, but, there is no reason not to torque them, if you have the rocker arm asembly off.

Wait to see if others say to "leave well enough alone"?

Thanks again guys. Will close up the rocker box until I've had some road miles on the engine.(after brake work, but that's another story.)

Volfandt, my oil pressure pretty much matches book figures, but here in SoCal the temperatures never drop low enough to peg the gauge during warmup like my previous stovebolts used to.

Quick story: Back when I was in my last year of high school in Trenton, New Jersey, driving my '38 business coupe, my Air National Guard unit was federalized during the Korean war. I had done well in the qualifying exams and was sent to Wright Pat AFB. The Chev was about to meet the Pennsylvania Turnpike, which then had a speed limit set at 70 MPH. Naturally, I had to try it. At the first Howard Johnson stop , I gassed up and checked the oil- 2+ quarts low with much of it on the firewall. I slowed down to about 60-65 and still spent almost three bucks on 35 cent a quart oil getting to Dayton. Was later told that stovebolts would run forever at 60 but last maybe three hours at 65. Good thing I had a fast speedometer like most cars of that day. Was back and forth on the Turnpike at least four times (at reasonable speed) with no problems.

Bill