bad oil leak on brand new motor

[Copperhead]

I just fired up a "new" rebuilt Magnum motor, a 408 stroker built about 4 years ago by a local guy who isn't in the business anymore. The motor sat from the time it was completed until I got hold of it a few months ago.

The problem: once the motor starts running, oil starts pouring out around the filter, almost like the filter isn't sealing.

Steps I've taken so far:

- the oil filter that was on the motor was replaced, and that seemed to make things leak less. I noticed the old filter was lacking the internal spring. The new filter is a K&N, and it has the spring.

- I replaced the large and small ring gaskets under the adapter plate. That actually seems to have made the leak worse.

I'm at a loss to know how to proceed. So what is going on here?

[Dick]

There is supposed to be a gasket under the adapter plate. It may have been left out during the rebuild.

[Copperhead]

Both the large ring gasket under the plate, as well as the little ring gasket that goes behind the threaded tube, were there. I replaced them just to be safe, and it didn't fix the problem.

I guess I should also ask if anyone has an image of the proper install just so I can double check my work?

[cudabob496]

Seems there should be steps to take before starting a motor that has sat for 4 years! Like priming the oil system, and maybe some oil on the rings, but I ain't an expert in this issue.

[DAHEMIKOTA]

I don't think he has a problem getting oil pressure. What may be the problem is the plate that is under the filter. There are two differant types. The older ones used a center gasket. Sometimes the gasket was one piece where the outer and inner gaskets were joined by three legs of gasket material. The newer plates have a depressed center and do not use the little center gasket. If you use the center gasket with that plate it will keep the plate from sealing the outer gasket. Try removing the little one and see if your problem goes away. Dan

[Copperhead]

Outstanding! Thanks, Dan. I will give that a try and post the results.

[John Kunkel]

In most cases the filter plate has to be pried off during a rebuild and this warps them enough that they will never seal. Try a new one.

[cudabob496]

Originally Posted by DAHEMIKOTA

I don't think he has a problem getting oil pressure. What may be the problem is the plate that is under the filter. There are two differant types. The older ones used a center gasket. Sometimes the gasket was one piece where the outer and inner gaskets were joined by three legs of gasket material. The newer plates have a depressed center and do not use the little center gasket. If you use the center gasket with that plate it will keep the plate from sealing the outer gasket. Try removing the little one and see if your problem goes away. Dan

You have more expertise than me on this one, however, had the motor been primed before running, that would have caught this leak. Also, there is other damage that may have occured, that is not presently apparent, when starting an engine after 4 years of sitting. But I hope that is not the case.

[Copperhead]

Originally Posted by John Kunkel

In most cases the filter plate has to be pried off during a rebuild and this warps them enough that they will never seal. Try a new one.

I'm picking up the new plate today, and I also ordered a new ring gasket. My supplier told me that I should be able to reuse the last gasket since I had just installed it, but I want a new one to be safe.
While we're on the subject, what is the proper material to secure the gasket? It looks like a layered paper gasket, which makes me think some kind of hi-temp RTV would be proper, but others tell me CopperKote would work. I have no idea what was on the old gasket, but it leaked. I used Copper on the recent gasket, and it leaked. I didn't use anything on the little gasket, just held in place by the center tension.

[Copperhead]

Originally Posted by DAHEMIKOTA

If you use the center gasket with that plate it will keep the plate from sealing the outer gasket. Try removing the little one and see if your problem goes away. Dan

I forgot to mention... the previous install used a thin center gasket that seemed to be some kind of MLS, and the plate leaked pretty good. When I installed new gaskets, the center ring was about twice as thick as the original, and this thing is a gusher now, so I'm thinking you're right about all this stuff. What John said about the plate itself was echoed by something my local supplier said. He mentioned that there was a run of the new-style plates a few years back that were warped and wouldn't seal.

So, new gasket, new plate, I'm hoping to get this thing running today.

[JVMopar]

Don't use any sealer. The gasket is for sealing. Just put the large gasket in and DO NOT use a gasket in the center.

The only reason to use a sealer like RTV is where gaskets meet other gaskets and on pitted or excessively rough surfaces.

[aarracer]

Question? Without the center gasket(of some sort), won't the oil bypass the filter altogether.

[John Kunkel]

The factory parts manual doesn't show a center gasket between the plate and the block, any leakage there is so miniscule as not to matter.

Same thing between the SB oil pump and the rear main cap, the factory used no gasket but many aftermarket suppliers include one which starts the debate.

[Copperhead]

I just got back from my shop. The operation was a success. Here's the details:

I removed the oil adapter plate and cleaned everything up. I didn't have any plate glass handy to check the new or old plates individually, so I took the old plate and the new one and compared their sealing surfaces by putting them face to face. No gaps were noticed and I indexed them several times to be sure. So if either of them were out of plane, it had to be so slight as to be unnoticeable.

I then stacked them together. I noticed that the new plate would nest perfectly on top of the original plate, but when I stacked the original plate on top of the new one, it stood off a fraction of an inch. About the thickness of the little center gasket, incidentally. Now I could see exactly what Dan was talking about. The later style oil plates are deeper and will join metal-to-metal at the block - unless - there is an inner gasket in there messing up the works.

I wiped everything down one last time, took the original plate and a new outer ring gasket, and screwed it down with the threaded filter tube. The truck started right up, and I let the motor "cook" up to operating temperature for about 20 minutes. No leaks, anywhere.

I have to thank Dan and John for their advice on the plate, and JVMopar for letting me know that I didn't need sealer on the gasket. I installed it dry, and its working perfectly.

[nhdriver]

Success! Thanks for letting us know what worked.