VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1933-1936 35 chev std rockers oiling volumes?

Hi there,
I have just had my 2 new rocker shafts and bushes from the filling station, assembled locally and refitted them to the car yesterday.
After starting the engine and revving it up, there was some oil coming from the TOP hole, but not very much, more like and Ooze than a dribble or a squirt. To me this is not enough to lubricate the valve stems and tips and on the other side, the push rods and below that the lifters?

Q1 : does any one know how much oil is supposed to emit from the top hole and do those parts get additional lubrication from MISTING in the rocker box, once the car gets running?

Q2 : Does the camshaft and lifters get its lubrication from the crankcase via misting or is it relying on oiling from the rockers above?

Q3 : I am using Penrite Chelsey oil about a 70 grade as recommended by Penrite. Because the engine is rebuilt and newish at this point in time, would i get better oil pressure up top if I used a modern multigrade oil?

I have also fitted an external oil filter system that takes its feed from the oil pressure valve that feeds the rockers via that small oil line going up to the top. The oil pressure before and after looks almost the same. I am wondering if it is reducing the volume and pressure to the top rocker feed?
All this conjecture depends on the answers to the questions above of course!

any opinions and advice gratefully received...

Peter

I think this interesting video will help you determine what is normal oil flow.With new rocker shafts that are dry, and dry fresh rocker arms, there is not a lot of high pressure and
high volumn oil going through the 1/8 oil supply line to fill that void immediately. As long as you are seeing oil delivery
I would suggest running the engine long enough to reach normal
operating temp, and give enough time for oil to fill all the cavities in the rocker shafts. We were taught to prelube the contact surfaces with assembly lube to avoid dry starts. Good luck; after a few minutes of operation normal oil flow should occur!

Can you be a little more specific regarding the oil you are using. I could not find it on their web site, and not sure what a "70 grade " of oil is. With a fresh engine I would be using a multi-grade detergent oil of 10-30.

Is Penrite 70 grade a SAE 70 weight oil? If so get it out of that engine ASAP. You need a SAE 10W or equivalent or 5W-30 or 10W-30. The low viscosity is necessary to insure flow to all parts including creating enough mist in the crankcase to lubricate the cylinder walls and piston pins.

With 70 weight oil it is surprising any oil is getting up to the rocker arms or any other place for that matter.
Bleeding of oil for a filter is not helping either. For sure the timing gears are starved also.

years ago the cars came from the factory with #10 oil. If I were breaking in a new engine today it would be with 5W-20.

hi there,

I phoned my engine restorer and told him of my concerns.
He immediately recommended , change the oil to at least 20/ 40 or 50.
this I did using penrite 20/50, I went to the shed to check the oil used in this exercise.....
started the engine and warming it up a bit looked for the oil at the top of the rockers....
the result was almost the same as before, very little oozing and nothing going down to the very important areas of tappet and push-rod lubrication...............??
what now?

My engine restorer said that to take it for a run and upon return, remove the rocker cover and inspect the area. He said that general misting would provide sufficient misting and overall lubrication, I am rather skeptical ......

Peter

thank you for the advice....

so many recommendations, what do I chose ?

If your engine restorer is recommending those oils I would find a new engine restorer. He does not seem to be familiar with older Chevy engines. I would be concerned that if he does not know the proper oil to use what else might not be correct. Following Chevgenes advise will be the best advice I can give.

Gene told you right on oil AND the oil filter. You must get that oil filter out of that oil line. It is killing both pressure (what little there is) and flow.

I am sure that ChevyGene will agree with the above. I sure hope that the engine rebuilder was more correct in his engine work than oil advise. High viscosity oils in those babbitt engines is a death sentence.

The Rocker arms don't reqire a lot of oil. The valve stems don't require any oil (I had umbrelas on my '34 to keep oil off the valve stems - 1948 and up had seals for that reason). The bottom of the lifters get oiled from the mist that is thrown-up by the connecting rods (Important -- that is why Chevrolet recommended a thin oil) . Any oil running down the push rods oils the lifter to push rod area (dosen't require a lot of oil ) and the faster the engine goes the more oil is supplied to the rocker arms.
The oil coming out of the hole on top of the rocker arm is fed by the grove in the bushing and the depth of the grove. The rocker arm oil is fed from the low pressure side of the oil pressure regulator whick also feeds the connecting rod pipes (important).
Perhaps you are expecting too much?

This question is related to something I've been wondering about--the appropriate oiling volume for the 1936 valve train.

When rebuilding the engine, I used a NOS valve oil routing assembly (goes in between the rocker shafts and routes excess oil back down into the engine).

My question: It doesn't seem like a lot of oil is going out through the rockers and coming out the little holes in the rockers--thus lubricating the rocker bushings, valves, and pushrod ends. This is especially the case towards cylinders #1 and #6. All of the parts are NOS/NORS--shafts, rocker arms (with new bushings), valves, and NOS head.

On all of the used rocker arm oilers I have (about 4 or 5), the tube routing oil back down through the head into the oil pan had been pinched to force more oil out through the rocker shafts.

Would it be wise, or would it hurt anything, if the NOS tube was pinched a little to increase the flow out through the rocker shafts and thus to the bushings/pushrod ends/valve ends? Or, perhaps try one of the used, already pinched tubes? I'm running 30 weight oil.

Thanks for any input!

I suggest you switch out the 30 weight oil for 10-W30 detergent, which is even more important with a freshly rebuilt engine.

Thank you all for the excellent advice, I did not realize that the weight of the oil was so important in a Babbitt type engine, and I guess many others to.
I will go into town and buy 5w-20 oil and again drain out the oil that I refilled the sump with yesterday.
I hope that I have caught it in time and will let you know the result.
Again thank you for all your help and support in this matter..

Cheers
Peter

I'm just about at the point of starting the rebuilt engine in the 33 & I was glad this discussion came along. I put the 5w20 in, put a drill on the oil pump shaft & spun it up. I had about 25 lbs. of pressure on the gauge & it was coming out of the rocker arm holes, which is a good thing. I just hope it doesn't have any leaks once I start it. Thanks, Joe

If the overflow tube is crimped more oil will flow to the rocker arms.
Must be the overflow tube after it gets past the rocker shafts.
If it were mine and I wanted to experiament I would work out some other ways to restrict the oil from coming out at the end of the tube- a way that does not mess uo the tube if you want to go back to original.
You could always hold your finger over the end and see what happens.
Remember prior to 1929 no oil was pumped up to the valve trains and required oiling only every few hundred miles....and they lasted for ever.

hi there,
I changed the oil again today, to 5w-20, and disconnected the oil filter prior to doing this.
The oil pressure was about 10 lbs and that is lower than before, I think because the oil is thinner.12 lbs was the before reading..

Oil was coming out of the hole at the top of the rockers, but only a dribble.
I reconnected the oil filter and the pressure was the same, no restriction....the dribble was the same.

So that is where I am at the moment, new rocker assembly, oil dribbling out of the top hole and thin oil in the sump to attomise in the required manner?

over and out..
Peter

As stated before, the rockers dont require a lot of oil so if oil is dribbling out the top hole of the arm there is plenty of oil there. If there was no dribble I would start worrying.
Tony

From your description you have plenty of oil at the rockers.

I agree also. If you could look under there runnung at 50 MPH with hot oil I am sure the oil would be flying in all directions.

Gene and others,

Thanks for the input! If I try anything on the 36, it may be putting back one of the used tubes that is already crimped. For some reason, this must have been a common fix for getting more oil out into the rockers.

I originally had a 10w30 oil in the car, but it seemed more noisey and held less oil pressure (it runs about 10 lbs pressure with 30 wt oil at speed when hot).

At first I feared that one of the rod bearings may have had too much clearance, but when re-checked they all had around 1.5 thousands clearance. My speculation is a valve or pushrod--sometimes there is a pecking and then sometimes it will disappear.

One item that has never been replaced is the oil pressure relief valve (it has a NOS GM oil pump). If the spring in that is weak, would it cause lower oil pressure? Is that common?

The normal oil pressure for a 1936 with a vane type pump will be about 12 pounds at 50 MPH and about 2 pounds at idle.
#30 oil and 10W-30 oil should have about the same viscosity when hot.
The gear type conversion pump I had in my 1934 had about 3 pounds at idle (which is a 1939 pump and that is also the pressure my 1939 shows) and 17 pounds at 50 MPH.
In the case of heavier oil giving a higher pressure only means the oil pump is working harder to push the oil through the main bearing oil gallery.
The higher pressure and greater capacity of the 1939 pump is an advantage in the 1935 and 1936 engines with the pressure stream connecting rod oiling. However the 1936 vane pump is sufficent for normal driving.

For you folks interested in max. output from your engines, just remember that more oil pressure requires more horsepower (goes into the pump and not out the crankshaft). It may be a fractional HP loss but when you only have 60-70 to begin with it can make a difference. Will effect the gas mileage by a fraction as well. As a wise person once told me "You can have 2 out of every three things you want. You pick two and I'll tell you what you get with the third."