4.3 liter Mercruiser cool down period

[Jimwhall]

So, inboards are new to me. For my outboard I'd let it idle and/or cruise around for a bit after hard running; I.E. going from tubing to hanging out at the beach. I am trying to do the same for the 4.3. I did notice, however, a couple hours after pulling the boat the engine compartment was still warm when I opened it to check on things. Is that an issue, or are these engines pretty durable.

 

[JASinIL2006]

Those blocks hold a good bit of heat. Perfectly normal.

 

[H20Rat]

About the only thing you don't really want to do is to go from hard throttle to shut off without a bit of idling. Some 4.3's in particular like to diesel if they are shut down without a little idling, and there is a risk of water ingestion if that happens.

But yeah, lots of iron and a couple gallons of water in the engine that hold heat, and although the engine compartment isn't sealed, there isn't going to be much passive ventilation either to cool off the engine.

 

[Lou C]

Not an issue at all 500 lbs of cast iron will retain heat for quite a while. In fact the temps inside the cooling system will rise slightly right after the engine is shut off.