Fresh Water Cooling

[Para]

In years past, for salt water operation an option called 'fresh water cooling' was really popular. It involved a bit more mechanical complexity, but the reward was that the 'core' of the engine was not exposed to salt water.....I assume you all know what I am talking about

In newer ads for boats I do not see much mention of this anymore. Have the engine manufacturers gotten so good with corrosion resistance that fresh water cooling is no longer neccessary?

[spareparts]

Closed cooling used to be common, when the epa got involved, they raised the engine temps to get them to burn cleaner, when they did that, they reused the old heat exchanger and left the manifolds out of the circuit, so now its only the long block, vs the whole engine. Manifold failure is the number one cause of engine failure in salt water, so if you are not cooling the manifolds, then why waste the money on saving the block, especially when a few years ago, long blocks from GM were pretty cheap to the marinizers. Some engines like the 8.1 and the 3.7 come from the factory with closed cooling because of extensive use of aluminum in the engine assembly. Crusader does a really good job on their closed cooled engines, they cool the long block, manifolds and part of the risers in the closed circuit. With other manufactures, you have to inspect the application to determine what parts are included in the closed circuit, there's no hard fast rule about what has what.