The Stovebolt Site Forums The Shop Area Engine Shop 54 235 Rocker Arm Oiler Assembly

Hey gang, someone "modified" my original rocker arm assembly oiler, and I'd like to replace it. I've checked with my local supply guys and they cannot help. I looked in several catalogues - no help either. Anyone have any ideas?? It ran okay (I guess) with it as modified, but while I've got her opened up I'd like to do right by her.

Thanks!!

It is not modified. It is supposed to be squeezed shut like that. It looks funny I know.

The '53-55 1st series 235s had the squeezed shut looking oiling connector. The later 55-62 engines had a loop to dump excess oil back on top of cylinder head.

chip

So now you ask!
I've collected a bunch of these things, I had so many laying around I'm losin' 'em.
So the squeezed shut ones are '53 to '55 1st. series huh?
Question: Does this mean then that the oil pump pressures are different and will one get into trouble using the "dump-loop" type oiler tube on the squeezed shut type motor? Does that question make sense? It seems the "squeezed" type wpuld have to be used on a motor with lower oil pressure and the open dump-loop one would be for a higher pressure motor. Will there be a problem switching them or do all the oil pumps from 1st to 2nd series have pressure bypasses? Anybody know?

Good question.

We've discussed this in depth, I wish some other old timer here could dig up the thread. Basically it has to do with an oil feed restriction in the block, later years were redesigned with better oiling supply, so the dump tube returns excess lube from the top end before it travels down the rocker shafts.

Its a interesting story about a removable oil line, hydraulic lifters, calibrated orifices and a special "grooved headbolt" that is listed in the books but has never been found in a motor.

perhaps somebody here feels like typing the backstory.....

The 1960 truck shop manual I have gives a good discription of the new rocker oiling design.

Starting in 1959 the oil restrictor was inlarged from 1/16" to 11/32" to allow more oil to the rockers. At the same time they moved the groove inside the rocker 1/4" off center so it did not line up with the supply hole in the shaft.
Also they pinched off the rocker connector overflow tube. All combined, this pressurized the rocker system.

Pre 68 Dave you are saying the opposite of what was posted earlier...namely that the squeezed or pinched off tube was from 59 on whereas the previous post states 54 and 55. Either way my 56 motor with hydraulic valves has the dump tube oiler on it. G*d willing and a quick carb overhaul kit delivery should see the thing running for the first time since the rebuild: will be interesting to see what kind of pressure I get out of it.

I wonder if any of this matters, do you guys know where this restriction is in the block? The 261 in my 37 truck is a 59 block,a 848 head pulled from a 56 car.The rocker feed was pinched closed at the end.I made an attempt to restrict the rocker oil supply by squeezing the little pipe close some near where it fits into the head.I don't know if it made any difference, the engine has about 20 K miles on it, oil pressure hot is 45 running and 35 at a 600 rpm idle using 15-40 motor oil.

Tony, The oil restrictor is the fitting that screws in the block at the back that the tube screws into, up till 1958.
In 1958 chev did away with the tube and made a new galley up the center of the block from the lifter galley. On that design the restrictor is part of the block, it is the size chev drilled the passage way behind the plug you will find in the center under the side cover.
I'm wondering why you would pinch the tube before the rockers? Did you feel you were getting to much oil?

Dave ,it was one of those brainstorms I get,looked like too much oil to the rockers to my way of thinking,keep more for the main bearings. So I tried to restrict it the easiest way possible, grab the Visegrips!.Made a slight difference I guess, you never know what'll happen until ya try it.

Tony, As I mentioned earlier starting in 1959 the restrictor size was increased to 11/32". If you are using pre '59 rockers with centered grooves and the connector overflow is pinched off, you will get too much oil to the valves. Also if you are using after market shafts with a flat spot ground the full length on a 59-62 engine you will also get too much oil.

Chevrolet had a way of overcoming the use of pre '59 rockers on later blocks by having you plug the oil passage in the block and installing a special head bolt drilled with a 1/16" hole through it, that the oil would now flow through to replicate the early flow requirements.

I have found for me the easiest way to do the same thing without the special bolt and plug is to braze closed the oil connector supply tube where it fits in the head and then drill it with a 1/16" drill. Sort of what you did by crimping it.

In the interest of reducing confusion, I double checked some old parts:

Pre'68 Dave is correct. The 53-55 motors had the loop, the 55-62 motors typically had the pinched-off feedtube.

With that said, I don't even remember what I have in my engine... '54 head on '60 block with new valvegear and I think the pinched-off tube & no restriction. Still got 30 PSI @ idle hot.

Hmm ok, I have the 54 block and I have to recheck the year, but a newer 848 head. I am pretty sure I have the crimped tube. And, my hot oil pressure aint great. Any ideas?

How's the oil pump and cam brngs?

Until you mentioned low hot oil pressure I assumed it was the cam bearings.

Hot oil pressure at idle isn't impotant so long as it's at least 5-10 psi.However it should jump up to around 35 at normal engine speeds.But an engine with 25 psi will be ok if you don't push it too hard.
A good 235/261 will have 30 or so at an idle and 40-45 running down the road.

When hot I have very good oil pressure the second I blip the throttle. This is mostly after getting off the freeway. Regular city driving doesn't really get it hot enough. But on the standard gauge it seems to drop to near zero at idle when that hot. I am known to keep the rpm up a little at the first light after getting off the freeway to keep the pressure up.

i have 235 out of a 62 chevy pu and it shows to have very little if any oil pressure at idle when it is hot but solid 30 when running down the road. i was hopeing it was just the gauge - no smoke or oil consumption that i can tell.

TonyM- You got solids or hyd in that 54 block? My 54 solid lift motor did use a restriction in the oil line in the pushrod cover. Keeps from pumping too much oil up top. But unless you've got oil flooding and spraying everywhere up top, its prolly a bottom-end thang....

Now its your turn to make an improper "bottom-end" reference.....

My plan for the motor is to get a cam from Patrick and then have someone change the cam bearings for me. If that fixes it I can put on the dual carbs. I am also still running multi grade oil. I was gonna try straight 30W and see if it makes a difference.

Could there be enough oil pumped to the top to starve the bottom enough to drop oil pressure? It would make sense I see that after sustained high RPM driving such as freeway driving. I see no drop in pressure after city driving even when up to temperature. But the lower rpms might help keep the oil in the bottom?

Oh, btw, they are solids.

Also, you say the restriction was inside the pushrod cover oil line or is it a nipple it is screwed into? I replaced my oil line because I messed it up taking it off.

My 261 has a pinched oil tube. I think the restrictor is actually part of the head.

On my 54, it was a brass fitting that screwed into the lower 1/8" passage. Then the oil line screwed into that. Then the oil line connected to the upper 1/8" passage at the center of the block, under the pushrod cover. The brass fitting had a smaller hole in it, didnt realize it was a restriction till our original discussion. If I can find it I'll let you know.

The question is, how much oil can be removed from the pan before the pump sucks air? And how much oil can be pumped into the rocker cover/pushrod cover at one time?

My 235s have always shown lower oil pressure after freeway driving. Ive always thought it was oil viscosity and clearance changes due to oil temp. Remember, the gauge shows water temp, not oil temps.

My motor is getting too much oil to the head, but I don't know what to do about it. I'm wondering if its contributing to my high oil burning.

How do I slow down the flow of oil to the head- '60 block, solid lifters, '54 head, '60 valvetrain, pinched rocker tube. 40 PSI running down road, 27-32 PSI at idle hot.

chip

Chip, are you using rocker shafts with the flat spot ground the full length? If so that will create a path from the shaft oil hole to the groove in the rocker allowing to much oil to pass. I just ran into this on a 61 engine recently. On that job I brazed the oil connector tube closed where it goes in the head and then drilled it with a 1/16" drill to make it more like the pre 59 flow design.

I'll have to look one day. I don't remember what the shafts look like. I bought the whole rocker assy new from NAPA. Lets just say its not starved for oil. Gonna bring car to machine shop soon that did the work. They said if I could get the car to them they'd figure out what my oil consumption problem is for free.

Okay gang, I guess I got this topic going but didn't get an answer...Does anyone know where I can buy a new (drop on the head type) oiler part for the 54 235??? My excess oil line (that supposedly drops oil onto the head) was cut and crimped and my oil pressure was around 60 before I tore her down. If someone has a good picture of whaqt it should look like that will help as well.

Thanks!!!

All the posts answered your question starting with the first one made by moi. That is what the tube normally looks like...

Bruce, If you e-mail me I can help you out.