Lifter Valley Oil Splash shield on 502 carb??
 

Do i have to run one??

putting the intake on my gen 6 502 stock with a gm dual plane intake and wondering if people are using an oil valley splash shield in there motors? I really dont want to use it because i dont like how the gaskets/ intake sits on the heads with the splash shield. The tabs on the shield hold the intake up, so i tried to modify the intake gaskets to clear the shield tabs but its didnt work so good as i need to remove to much material to make it work.

Did the carb 502 come with the splash shields??? I am converting a 502 MPI to carb so the MPI had the shield, but i dont want to re-install if i dont have too.

you can assemble without the shield,but it is made to keep the hot oil from the underside of the manifold.

I would use the shield. Notch the gaskets to clear the tabs. It will help keep the intake cooler.

I did notch but the center tabs make it so i needed to knotch the center of gasket and when i notched it it made it so that oil can now fill up the little pocket under the exhaust cross overs.

did 502 carbs ever come with this shield and what gaskets did mercruiser use.....none of the parts fieche show a oil shield..

That shield was used on all Gen V and Gen VI motors, carbed or EFI.

Oil Splash plate trick
 

I'll give you one of Raylar's and other engine builders little secret tricks to also make sure the oil splash shield stays in place on a GM hydraulic lifter engine such as the Gen 5 & 6 454 -502 engines.
We use three longer bolts with bushings that hold down the lifter retainer plate and they sit just touching the bottom surface of the splash plate when its installed. Many have sometimes found that with the hard hits high performance boats take when running that the splash plate can come dislodged and drop down and come in contact with the pushrods and when it does it makes a hell of a lot of awful noise and can also create a bad condition in the lifter valley especially at high rpms. This extended bushing and bolt trick will support the plate in such a way that it cannot come loose and create problems.

Best Regards,
Ray @ Raylar

So do you just cut and remove the tabs that are suspose to hold it in place and just use the bolts?? I just can believe that merc/gm doesn't have gaskets that are designed for the tabs so it does keep the intake pushed up creating a leak..


If the gen 5 and 6 came with them then then i should have the right gaskets, but no provisions for the tabs and they will leak if i install the gaskets with the tabs under them.

I was thinking about notching the left and right tabs and removing the center and then doing the bolt trick??

I have had both gen V and VI apart and never seen one from the factory....have run them though...can't hurt..Rob

I have always used Merc gskt sets and they easily clear the tabs.

What intake gaskets are you using???

27-805722A1 and its going on a gen 6 502 415hp carb....now most gen 6 are mpi and this use to be and it did have it in the motor when i took the mpi off. Maybe if i use the gaskets for the mpi on the carb intake...what is the difference in gaskets, shouldn't they be the same...i think they have didferent numbers though.

Here is what I would use--

27-805403A1

what are those for? what gen/ carb or mpi? And you say that you rune these with a splash shield?

Tried to find a pic of gasket and only found one on on ebay (searched 27-805403A1) and its hard to tell if the center has a notch for the tabs...it appears that the left and right have a notch for the tabs...looks like its has the exhuast crossover blocked and has the rubber rings around the ports.

Why do they only list these for the MPI 502 and list the other gasket that i already had for the old carb 502...

I dont need to run the exhaust crossover open right?

the splash sheild, in addition to what's already been mentioned, helps with oil leaks that are common in the lifter valley area.

See im in salt water and i have had a hell of a time finding gaskets that seal up good on the brass lined cooling ports, all the ones that have rubber rings on the gaskets dont fit, they seal half on the brass nad half on the aluminum and i know that will just leak in a year or so....

That gskt is for Gen V and VI for MPI, but I think it is a good choice for anything. It has good sealing properties and I always put Ultra Black on the gskt at the areas that seal around water ports. I put a very thin layer on both sides.

Worked awesome!!! Got it today and just installed the intake with the splash shield thanks!!!

And there you have it !!! Glad to help !!!

Smitty

You need to leave the splash plates in to keep the hot oil off of the underside of any intake on a Gen 5 or 6 engine. It keeps the intake charge cooler and helps power development and cuts down on possible hot air charge and detonation issues.
Do not cut the tabs off when using the bolt stud trick. Just use the correct gasket set that when properly installed has enough material taken off or missing to clear the tabs.

Best Regards,
Ray @ Raylar