HI all. Thanks in advance for assistance on this issue.
My car is a 78 Corvette with the original L82 350 motor.
While looking for a water leak into my oil I found a mangled lump of stainless steel mesh in the inlet of my oil pump in the sump.
After pulling the inlet manifold and finding the water leak (broken inlet manifold gasket) I also noticed in the valley under the manifold four holes. One in each corner. Three of these holes had mesh but the forth hole was missing any mesh.
I have attached a photo of the front of the motor showing one hole on the left and a mesh covered hole on the right. I think this is where my mangled lump of stainless steel mesh came from.
Can anyone tell me what this missing mesh part is called and where I can get one?

 

That is home made and not original.

 

Kits are available to put screens in all the oil drain holes in the lifter valley.
I think the idea was that if there were a catastrophe in the top end, the screens would prevent debris from dropping onto the spinning crank or into the pan.
Most builders quit using them years ago.

I've seen thousands of pictures of engine carnage but never one of debris from a top end failure that caught in one of those screens.

If it were me, I'd remove the remaining ones.

 

 

Thanks guys. You have answered my next question which was do I remove the others.
I very much appreciate your knowledge and advise.
Thanks again.

 

When you say "the others" are you referring to the remaining one at the front of the engine, or did the previous owner also epoxy the ones into the rear of the block oil drains, too?

I had a set of these, a LONG time ago, purchased as a kit by Moroso. The ones in the front of the block were different than yours. The Moroso screens for the front, were somehow bonded to "rings", that were then pressed into the openings in the block, then you used a center punch to create a couple of "dimples" in the surrounding metal, which held them in place. The screens for the rear drains, were screens that were formed into a sort of "funnel shape". and they were slid into the drain openings, and held in place with epoxy.

OP, it you choose to remove your screens, you'd probably loosen the epoxy, which could then float around the engine. Unless your engine is disassembled, or at least the oil pan is off, you need to be really careful.

 

I personally know that my screens are secured with epoxy and the chances of getting it all out are minimal. Screens were a good thing in the early days of roller rocker arms as they had a bad habit of falling apart. I have screens in my 427 BB and the same guy who glued them in also painted the inside of the engine with Glyptal which seals the pores in the cast iron and makes the oil return to the oil pan faster.

I would only remove the screens if I were rebuilding the engine at this point. To many risks otherwise.

 

Best just to leave them alone if they are still solidly attached to the block. I personally don't see much purpose for them on a stock engine.
Yes, something can break in the upper area and those were designed to prevent large items from going deeper into the engine areas (oil pump at one end, timing chain at the other) but it just seems pointless for the most part. Any item that makes it past those filters will make it past the oil pickup screen in the pan as well and you can guess the rest.
Engine blocks are known to move or shift because of the continual heat heat cycles they endure so the epoxy has to be flexible enough to adjust to these core shifts. Although I would guess that the failure was caused by improper surface preparation more than anything else.
At least physically inspect the others while you are in there to make sure they are still solidly attached and not just hanging on with simple friction fit... good luck.

 

There are three more screens in my engine. One in the front and two in the back. I will see how solidly attached they are and if loose I will remove it. I do have the oil pan off at the moment so will be careful to remove all the loose epoxy.
Thanks again.

 

They should be rock solid but even testing them "hard" might break or loosen the surface hold. Test them but don't try to break them off or they might come off and in doing so introduce some nasty little pieces of epoxy into your lubrication system.

I have several screens inside my Big Block as well and they were put there in case my Comp Cams Roller Rockers arms decided to let a bearing loose. That was a concern for a 427 balanced up to 7000 rpm. We designed my 427 for abuse but 7 grand on the tachometer is a bit to much for a 427 BB with 12.25-1 compression. It pulls hard up to ~6400 rpm and goes fairly flat.

If you do remove one I would be sure that you get all the particles out by flushing oil over the area where the epoxy was and catching it in a pan under the engine. I have a Huge magnet attached to my oil filter but it won't stop JB Weld or Epoxy floating along in your oil. Any small loose pieces of RTV are a killer when loose in your lubrication system as well.

The only negative is that when the engine is cold you can pump so much thick oil up to the valve train that it can slow the thick oil from returning to the oil pan. For this reason I warm my engine up before putting a load on it. After this no more trouble.

 

Well, here's a thought.
Did GM ever install such things?
It sounds like there MAY be a sleight chance that they will help. But, seeing that 1 has already let loose and was traveling around, I would remove the rest of them.
Since you've got the engine apart, it's now or never.

 

Understand your point, but did GM install roller valvetrains in these engines, as original equipment....and did they design them to rev to 7000 RPM, as they came off the assembly line?

 

I've come to the conclusion that many, not all, aftermarket parts just aren't needed, are a solution to a problem that doesn't exist, or give minimum increased performance.
It does seem that a large percentage of problems come from using the wrong part or using a part that is not correct for the application--using race parts for a street car, etc.
Any more, I'm a minimalist. I don't use anything that will make it more complicated or potentially less reliable.
The OP has a 25% failure rate for his screens. So the question is, does he need them? What are the pros and cons? Will any more of them fail?
I doubt that there is a 100% correct answer as to remove them or not.
It probably doesn't make much difference, but, I'd remove them.

 

I'm not an expert by any means but if it were my engine I'd remove them. If one already came out and wound up in my OIL PUMP why take the change of another doing the same?

 

Just to add another element. Here is a photo of what I found in the oil pump inlet screen.
I don't really want the chance of another 3 of these floating around my engine.

 

The prevention of failure became the failure.

 

Now that is a good point. With respect to the topic at hand, those screens were designed for race engines, engines that under "normal" conditions, aren't used on a daily basis, therefore any "glue" that was applied to the interior of the engine wouldn't be subjected to constant heat/cold cycles. And secondly, the engine would be disassembled and thoroughly inspected at the end of each racing season. In this instance, failures of the glue holding the screens in place, would hopefully be caught before the screen became dislodged.

 

Curious....as the whole valley has been polished with an abrasive roll. This was a common thing in the 90's when a block was "race prepped"......the idea was to help oil drain back, along with the valley screens. All the big names abandoned this process as it was more work than the benefit it reaped...which was very little. The other thing is valley screens were installed specifically to catch pieces of a roller lifter when it exploded....to keep it out of the way of the rotating assembly.......not normally used on a block for a flat tappet application. Wonder why all of this work was done to this.....I also spy a Double Roller timing chain......you may not have the original block.....somebody has been in there doing a lot of work.

Jebby

 

Hello Jebby,

The path my engine builder/mechanic chose to go was building it like the other Race Engine's he was known for building. The guy worked on Can Am cars back in the mid to late sixty's and was familiar with a lot of little tricks he had learned. The man was the most Detail oriented and was meticulous in the way he build engines. When a person refers to "Balanced and Blueprinted" engine that is what my buddy did on my engine.

We did the build over a few months and many potential customers saw the quality of his workmanship and for his end of the year Christmas Party My engine was on a stand in the center of his showroom area. Several people wanted my engine but instead he sold orders and was building a bunch of Big Block Chevrolet engines for several new customers. As he finished my engine he built a Ford 428 Cobra Jet for a Frame that Carrol Shelby forgot about for 40 years. The Ford engine was a lot different than my 427. In the end I met the owner on the road one day and I was able to trounce him in a "New" AC Cobra. He could not corner or accelerate as fast as my 427.

You are absolutely right about Waiting to catch the pieces from a Roller, My engine was built in the early-mid 1990's and the reputation they had was not the most reliable and this was cheap insurance according the the builder. He didn't like the compression I put in my 427 so he had some Head Porting and Polishing. All gasket matched and when finished the engine was a piece of art that I would be pleased to display in my home (Maybe not my Wife's feeling).

Again as far as removing the screens, they have been in my engine for 25 years or more. They are secured well and none are loose. If and when I rebuild this engine again I will probably remove them only at that point.

The Glyptal is secure and not peeling either so I am going to leave it alone. The smooth surfaces inside the engine do help the Hot oil rush back to the oil pan to be used again. It makes sense and is an old trick like Jebby suggested.

My engine was designed by me with the help of my buddy. It was so nice to have the list of parts in this engine, we spec'ed out some nice parts. I could not find a good pair of aluminum heads back then for a Big block back then. The only affordable aluminum heads were used from an L88 or L89 1968 Corvette. The damage would require major aluminum repair as the coolant had eaten through parts of the heads. I would not spend $2k on heads with holes eaten through them unless I could repair them effectively and easily.

 

You can soften EPOXY with a Propane torch.... Smells TERRIBLE! but it will soften and not crack and then you can pull it out.

Unkahal