The Stovebolt Site Forums The Shop Area Engine Shop 235 Under The Valve Cover

Replacing the gasket on my 235 before painting. If you don't know me, I have never worked on cars before let alone seen an engine. So here's a shot from under the valve cover. What's up with the corrosion? Normal?

http://i.imgur.com/Su6ZW89.jpg
http://i.imgur.com/tQ4nBB8.jpg

How often was the oil changed? What type of oil are you using? Seems to me that once the oil gets up to temp it will absorb the moisture still present. The rust may dissolve in the oil if it has a high detergent package to it. I'd probably be diligent about oil and filter changes though the rust is probably from condensation and the possibility that the engine was ran cold too often. I have had engines that had steam type vapor come from the breather until the engine warmed up. 

Just a thought

I would say condensation causing that, but you do need to clean it up and open up the oil holes that look to be blocked. In the second picture, the rocker arm in the front you can almost see the hole for the oil so come out of on the left side of the center of the rocker. All of the holes need to be open.

It isn't exactly normal, but not unheard of. You need a lot of time on the highway (like 2 hours) in cold temperatures (like 20°)to evaporate all the condensation up there, correspondingly less time as the ambient temperatures increase. Many years ago I had smashed the little louver/vents on the valve cover shut in an attempt reduce dust intrusion. Well, they were put there for a reason. I eventually had chunks of rust falling off the valve cover. I ended up getting a nice shiny aluminum valve cover, which will get some corrosion I'm sure, but nowhere near the extent the steel cover did.

Probably a result of the engine sitting and not being run for a time. Pull the rocker assembly off and clean things up and you will be ready to fire it up.

OK, do I "open the holes.?

How do I pull the rocker assembly and clean them? Wire brush?

Take pictures from many angles.
Loosen up the bolts which hold down the rocker arms.
Remove the entire rocker assembly.
Take some more pictures of it while it is on the bench.
Disassemble it being careful to organize the parts so they go back where they belong.
I use a wire wheel on a bench grinder to clean up the rust (and to scatter small parts into the deepest recesses of my shop ).
Check the rocker arm shafts for galling, and the rocker arm tips for notches where they contact the valve stems. The tips can be carefully polished smooth.
Wash parts in solvent without mixing up the parts.
Make sure to clean the crud out of the inside of the rocker arm shafts.
Reassemble.

Here's a diagram of the arm shaft dissassembled from Tim's (tclederman) website. 52Carl just listed the order of the procedure.

The whole assembly will lift of the head as one piece, and you can separate it for cleaning on a bench. Be careful to keep everything in order.

Brad

Is it going to f-up the engine to run it while the tops of the rockers are rusted like this?

Rust is hard and sharp. It gets everywhere. Bearings are soft and smooth. Mixing them is a very bad idea.

Since you already have the valve cover off, it is a good time to go over the rocker assembly. They all get gunked up and can lead to serious wear of parts that no one makes anymore.
Carl

OK, pardon this dumb question but is there any safe way of cleaning these tops without removing the whole darn thing and most likely doing far more damage?

No, take the darn thing off and clean it up. Take your time and lay things out as you take it apart.

Here's a VIDEO of a '51 216. Hope this helps. This is actually part 2,of a 3-part video. The first one doesn't show much. blob:http%3A//www.youtube.com/57b4b637-0854-4ddd-a370-8ad14496781d

Only one problem with the video, he put the shafts on upside down. The rocker oil supply holes go down.

Yeah,but he gets the idea that it's not as hard as it seems. That's MY point. He does have some good tips about cleaning the journals,though.

Elect a Wire Gauge Twist Drill which will match the Diameter of the little Oil Holes in the Rocker Arms.


Twirl the Drill Bit with your Fingers to clean the blockage out of each Hole.

Test that all the little Holes are then able to pass OIl alright by turning the Engine over with the Starter with the Ignition 'Off'...and after a dozen or so turns you should start seeing Oil gurgling up through the little Holes.


I think the corrosion we see here has accrued for a long time. This did not happen over night or in one season I don't think.


If the Engine is run and not run long enough to thoroughly heat up...it can not evaporate Condensation in the Crank Case.


And yes the best way to really clean all this Rust up, is to remove the Rocker Arm sub-assemblies.

And if removing them, best make some sketches to aid you in knowing how to re-assemble it in exactly the same way it is now.

Each Rocker has a little Part Number on it, and there are two Shafts.

Keep these two Shafts seperate...( or even just remove one dismantle and clean, set aside with a Note as for which one it is...then, remove the other ) and note the Order of the Rockers as per the orientation of each Shaft.

Or I suppose you could leave it on...and Plug all the Oil Drain Holes in the Head with twists of Paper Towel.

And use an Electric Drill with a Wire Brush Chucked up in it...and remove all the old Corrosion that way.

Bearing in mind you want to make sure none of it ends up being able to be carried down the Drain Holes where it would get into the Oil Pan Sump...

So Plug all those pro-tem and Plug them good...and figure to also manually clean the general area once done Wire Brushing all of it...

You can clean with any Solvent or Kerosene or Aerosol Carb Cleaner and Paper Towels or Kleenex...make sure all is really "clean".

And then remove the pro-tem Twists of Paper Towel 'Plugs' in the Head's Oil Drain Holes.

If you are careful I think you can do it and do a nice job of it even, leaving the Rocker Shafts on and abiding the cautions stated above.

Even for people familiar removing and completely dismantling the Rocker Arms, it is kind of challenging to keep everything noted somehow or other so it all goes back EXACTLY as it had been with no substitutions or goofs.

So leaving them on and cleaning them in place would be enormously less difficult.

Thanks all. Having read what everyone wrote and knowing what I know about the engine (bought Nov. of '13 when it ran and ran well) I thought I'd see if this was just rust from condensation from the very hard and wet winter during which the engine sat on a tire in an unheated garage. So before I took a wrench to it I took a rag. Here it is after:

http://i.imgur.com/IAdAWL3.jpg

Nothing came off in chunks and there was no solid debris anywhere in there.

Now, what do I need to oil before the cover goes back on and what sort of oil is correct?

And yes, I'll open the oil holes on the rocker.

What good news!

I had really assumed the worst!! Lol...

You do not need to Oil anything.

But just for your own satisfaction, consider to turn the Engine over a few times till you see Oil coming up out of the little Oil exgress Holes you will have cleaned out, in the Rocker Arm Tops.

And check your Valve Cover to see if it's Mounting Holes are 'dished' from prior tightenings or over-tightenings, and if so, gently tap them back into being 'flat'.

It was a huge load off.

Can't start the engine yet but this will be what I do when I get everything assembled and ready to run. Valve cover is new so no dishing.

While we're on this top, what is the mod I see where an oil line is fed from a T in the oil pressure stem to the other side of the engine to get oil on top of the rockers?

I think it is the "216" which has that.

you really need to get a shop manual, available from many of the standard vendors. Or at least go to "old online chevy manuals" They have nearly all the manuals downloaded.

My 48 216 had a bad condensation problem in the front of the valve cover this past winter. I went to a hotter thermostat (160 - 180), blocked off the vents, added an open PCV system to no avail. I probably had that valve cover off atleast once a month for the entire winter. While I had it off I'd wipe everything down so my valve train looks pretty good.
You need to remove your valve train and clean it up. All that rust and corrosion took more than one winter to accumulate. That crud thats built up on the rockers is going to flake off, circulate in the oil and eventually damage your bearings.
I don't know what the ultimate fix is for topend condensation but an occasional valve cover removal and wipe down is about the only suggestion I can offer in the winter. I have zero condensation problems in the warm seasons....
Good luck
Dave

Just curious if a block heater would help keep the condensation away over the winter? Im not sure if the heat would rise up through the motor into the valve train?
Mark

look on the bottom of this page linked earlier
http://www.1954advance-design.com/W...l/1948-63%20rocker-arm%20oil%20tube.html
it shows the sealed tube like you have



here is a good way to check the oil passages from big tonkas web site

https://picasaweb.google.com/113636046886857960240/New235?noredirect=1#5748527603210399186

Nice. Questions: one lead of the oil gauge goes to something in the top where I just have a hole. What goes in here? What does the other lead go to?

What does he have attached to the drill? Is this the pump that's part of the distributor?

The oil gauge "sender" line is usually attached to a fitting on the lower rear of the driver's side of the block. Other attachment locations for the oil pressure sender line might be used.

If you have a by-pass oil filter, the oil pressure sender line is usually attached to a T-fitting on the lower rear of the driver's side of the block, with another line from the T-fitting going to the in-flow port on the oil filter canister.

It looks like you did not get a clear and complete answer to your question: "While we're on this top, what is the mod I see where an oil line is fed from a T in the oil pressure stem to the other side of the engine to get oil on top of the rockers?" That line from the driver-side of the engine to the middle of the passenger's side of the head is a cob-job attempt to get more oil to the rocker arm assembly. This "adaptation" might be found on 216, 235, 261 engines.

looks like hes using an old distributor on his drill,
a large cut off flat blade screwdriver will work also.

oil gauge is mechanical, line comes off gauge to the port on the block. if you pause his video near the end you will see where its attached.

Yes, at the end of the video you can see where the gauge is hooked up at the low side of the block. But there is another lead off the gauge that is going to the hole towards the rear of the engine right next to the valve cover. What's this?

Thats the temperature sender screwed into the head
steve sr.

If it were me I would remove the rocker arm assembly. Clean on the bench and reassemble. Change the oil and filter(if you have a filter). Reinstall the rocker arm assembly and start her up and go. But that is just me.