anybody ever see a stock intake manifold casting look like this?? '90 454 MAG, looks weird around the front water passage, like it was cast twice?

Nevermind, saw a better pic this morning.

Looks like a FFU....factory f@#k up...

That's the high Dollar Quality Junk Mercruiser likes to pass on to it's customers..... It's nice to see they think there junk it worth gold and it is good enough for us.

My 1988 365mag engine, one had that problem. The casting was very poor.

after doing a little searching it seems this isnt all that uncommon... great!

You guys really not familiar with this?

This is a GM aluminum dual plane rectangle port intake with a "cast in" bronze water crossover. It's for corrosion resistance. The Dart HP500 carb intake is the same way.

Sure, that particular example isn't nested in there as "pretty" as some of them, but I've seen lots that look just like that. As long as they don't leak at the gasket area, there's nothing wrong with running em like this.

MC

I don't know about all...but I have seen HP500 dart intakes that have are not brass lined..

That's what it is. the black paint and all the black hoses hid it pretty well in stock form. When I added cam driven water pumps I could see it so I took some JB weld, smoothed it over like Bondo and re finished. It had run for 15 seasons before I found it.

On WARRANTIED products, Merc uses motor parts with either brass/bronze liners or hard anodized components in the aluminum that will be in contact with "hot" saltwater. There are two part numbers for the Dart intake, and while I don't know for certain, it might be that one P/N was bronze crossover, and the other (newer) P/N may be hard anodized.

MC