Cavities on my360 Intake Manifold?

[CaptainGlenn]

I have two cavities, in the center, one on each side of the intake manifold were it meets the head. Is this normal? I seam to be getting oil blow by from the starboard side cavity.

 

[Tahoerover]

It's a exhaust cross over. Sounds as if your gasket has failed and crankcase pressure is pushing oil out the frailer. Remove the intake and replace the gasket.

 

[fastjeff]

And when you do, don't omit these little metal plates that come with the gasket set.

Jeff

 

[CaptainGlenn]

Here are a couple of pictures, I almost looks like it's the wrong intake? Does this look correct?

 

[Tahoerover]

It looks correct.

 

[CaptainGlenn]

Thanks again.
The gaskets Jeff is showing is all I need? The gasket alone is all that covers the cross overs?

 

[Tahoerover]

The cross over is for automotive apps. In a car or truck there is a valve in the passenger side exhaust. When the engine is cold the valve will close and it routes the exhaust from the passenger side up and over to the driver side of the engine. No valve in a marine install so the cross over has little pressure on it.

 

[JJDebeers]

I have the same situation with one of my 318s. I'm wondering if it's worth replacing the crank case vent also. Is it possible that the vent isn't venting, causing the pressure to blow by the cylinders?

-JJ

 

[fastjeff]

Your motor must have a functioning PCV valve circuit or it WILL blow gas out and not remove moisture from the oil, resulting in acid build up and sludge.

Jeff

 

[CaptainGlenn]

Thanks again all, I ordered a gasket set today.