Anyone have a solution for sealing the four screws that secure the valve cover on a 1955 235? I'm using a flat machine screw head, external star washer, and the stock spreader washer. Lately, I've been getting some oil in the external ridge of valve cover that finds its way to the rear of the engine. Here's an old pic, zoom in and you can see what I'm talking about. Would an o-ring solve this leak?
Wondering why the gasket is not sealing this area? Pull the cover and inspect the gasket around the bolts. When you re-install turn the v/c over and place a 1/2 inch socket under each hole and using a ball peen hammer, work each hole to get a slightly domed shape. When you re-install the cover the bolt will have a bit more pull down room. You can, if you want, put a dab of gasket sealer in each hole before putting the bolt in. Just some suggestions, I’m sure others will have some too.ðŸ›
Martin '62 Chevy C-10 Stepside Shortbed (Restomod in progress) '47 Chevy 3100 5 Window (long term project) ‘65 Chevy Biscayne (Emily) ‘39 Dodge Business Coupe (Clarence) “I fought the law and the law won" now I are a retired one! Support those brave men/women who stand the "Thin Blue Line"! Hug a cop! USAF 1965-1969 Weather Observation Tech (I got paid to look at the clouds)
If you use washers at all, try dead soft smooth copper ones, like the ones on an oil pan plug, and use blue LocTite to keep the screws from backing out. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
My take on this is the last place a valve cover gasket would leak would be at the compression points. You say "the screws are leaking", I can't see by the picture, but are you really saying the valve cover leaks?
One common mistake is over tightening, Seen it many times. Done it myself. Get a new gasket, use pan head screws with spreader washer. The star washers may have encouraged you to think they are lock washers and you needed to crank down. They are to be slowly tightened to snug. Crisscross pattern. They may need to be re-snugged a few times. Very carefully.
We don't know the history of this leak, that would be very helpful to determine cause. I.E. Out of shape cover or holes that need work as Martin describes. That would be if it has always leaked. Do check the cover, per Martin, for surface flatness and hole perimeter distortion.
If recent a leak........ over tightening/gasket over squeezed, no compression left. Gasket too old...........etc. Looks like you are using a good name brand gasket. Just be sure it's thick enough. Cork has always worked.
There are good gaskets and there are bad gaskets. There are different thickness gaskets. The cover, done properly, will not leak. I would not use any sealer except if the gasket comes out of the package non linear and won't stay on the cover in the right place, it may need a super light tiny dab at the bad spot. Tape it until it stays with screw in the holes. Gasket to cover only.
Why do your screw heads look so white?
Andy, I've seen your posts before. You know what you are doing. My post is just basic stuff, a refresh or a idea jogger. Not trying to be an instructor.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
I believe the oil was finding its way up through the screw holes and screws in the valve cover. There isn't any sign of a leak between the head and the valve cover since the oil collects in the lip/trough/side of the valve cover. It's probably done this for a while and has gotten progressively worse over time. When I put this engine in the truck, I carefully worked the valve cover holes and ended up with a good mating surface. It's likely the screws were 'snug' but not over tightened. I think the oil just worked through the gaps in the external star washers since that's where the oil is collecting. When I put the 7/32" valve cover gasket and spreader washers on, the original bolts were too short. The valve cover bolts that I removed had star washers on them, so I figured it must be a good idea. Not! There is no sign of oil coming from the oil fill cap. Here's another pic taken this evening. I'm using stainless steel screws and the available light makes the screws look white in the old picture.
Bartamos, thanks for the vote of confidence. I appreciate all the input and advise I get here on the Stovebolt, it's what keeps us all coming back time after time.........
You may want to run the engine with the cover of to make sure that the rockers are not over oiling. It is also very easy to make small gaskets to fit under the head of each screw.
That's an interesting idea. Recently, I added a spin-on oil filter and added the 1/16" reducer in the outlet port for my 235 with a bypass oiling system. Could that have caused this problem? I've noticed my start-up oil pressure and warmed-up oil pressures are slightly (about 5 psi) higher than before the filter was added. An open PCV valve system was also added a while ago.
I plan to pull the valve cover and check to see if the rockers are over oiling. How is that checked, at an idle or higher RPMs? If they're over oiling, how is that corrected?
On a 1955 engine the center oil connector should have a over the top loop to dump excess oil back towards a drain hole in the head. If a 1959 connector is used, or the drain loop has been pinched off, that can cause over oiling.
Oil should just lightly flow from the rockers at an idle.
Okay, thanks Dave! I ordered a new valve cover gasket, it should be here tomorrow morning. In the meantime, I got to thinking about those small gaskets. Armed with my hollow punch set and some 1/64" gasket material, I made some of those gaskets with the 1/2" and 3/16" punches. The gaskets thread onto the screw and fit quite nicely under the spreader washer. I figure if it stops the leak, the valve cover gasket must not be sealed around the screw holes. I'll check the oil connector when the new valve cover gasket gets installed. BTW, I did find some good YouTube footage of 235 rocker oilers at an idle.
If the oil is some how getting to the threads and migrating up the threads and thru the gasket, then just coat the threads with high tack, or something. Adding a fiber washer would not stop it if that is what is happening. If that is what is happening, you need to seal the thread. Jerry said locktite way back in the post. I lean away from needing locked and toward needing sealed. Locktite may seal but I don't like it on those particular screws.
There is not much pressure in there. If there is, maybe you created a problem with some recent PCV action you took? Does the cover have any "openings"? If so what type? Was any "opening" recently changed? I did read about the spin on filter..............But not super clear on what all that was.
I don't know what's so bad about over oiling a motor and I don't think 5 lbs extra oil pressure is a big deal. I now am forced to lean towards a non flat cover or bad gasket. I've never seen oil migrate up the threads of a valve cover. I would like to know if it is both sides, and how many "screws" are leaking.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
I did put some sealer on the threads when I added those small gaskets. When I removed the star washers, all four screws had evidence of oil creeping or leaking. Today, it appears that the DS were not leaking and the PS were definitely leaking. Yes, I've added a spin-on oil filter and a PCV valve, but I can't imagine those being the problem. The engine has bypass oiling so a 1/16" reducer is in the outlet side of the oil filter. The PCV valve was installed in a modified draft tube and is an open system. There aren't any vents in the valve cover; however, the oil fill cap is vented.
This gasket has been in place for around three years. Recently, I noticed the oil accumulating in the lip of the valve cover. I do not find any evidence of an oil leak between the gasket and the head. I'll run it again tomorrow. Most likely, the gasket has just failed or I didn't have it sealed very well in the first place.
Yes, gaskets would take a "set" after three years. As we tighten a little each time they finally have nothing left. I'm hoping and betting on a new gasket. Good job Andy. You won't need those washers you made. Be sure the fill cap is actually venting.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
Okay, I put just over 35 miles on the '47 this afternoon. With the gasket washers in place, the four screws are basically dry. After driving the last 200 miles or so, the lip around the valve cover would be full of oil and running down the side of the block by the starter. It's not today; however, it appears I'm also getting some oil from the oil fill cap. This is a vented fill cap and it is venting. The gasket is loose and is quite worn. I have another fill cap, so I'll give that a try. The new valve cover gasket is on the workbench, just in case.......
At least I know there's oil in the engine, right?
BTW, I pulled into my garage after this 'test ride' and a guy followed me right up the driveway. He offered me $15,000.00 for the '47 on the spot! The '47 is still in the garage, don't tell my wife, LOL!!
my '57 235 used to do the same and I fought it with sealers and new gaskets, cork and synthetic. pulled the cover and checked for flatness and was surprised how bad it was from past sins from who knows when. When it had leaked in the past I think previous owners must have continued to tighten the screws until there was no way it would ever seal.
Larry Old man᠁Old truck᠁neither one goes very fast. All you need in life is TIME, PATIENCE and MONEY. If you are missing one component, you'll need an abundance of the others two.
Using some 3/16" thick aluminum, I built 4 spreaders and my rocker cover has never leaked a bit since. Make a template out of cardstock, use a saber saw to cut the aluminum and bend upward slightly in the middle. Good luck.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
Jon, that's a great idea, thanks for sharing it with us! The next time I'm fiddling with the valve cover, I'll have to make some of those spreaders.
As I look at my valve cover, I think the leak was coming from the oil fill cap the entire time. I guess I just never saw the trail of oil from the cap, down the side and pooling in the lip of the valve cover. The oil must have just migrated toward the rear of the engine (natural slope) and collected on each side of the valve cover. Since I put the gaskets on the screws and replaced the oil fill cap all is well.
