I just did a quick web check. The boat cable I found is only rated to 105 deg C. http://bestboatwire.com/catalog/default.php/cPath/23 Is that high enough? I would guess not for all locations in the engine, especially in the wiring located right on the engine. Is there a higher temperature spec for boat wire than this?

One of these days I am going to rig my thermocouple reader to monitor engine compartment temperatures at various locations so I can see just what is going on in there. I am just enough of a nerd to do this, too :-P I live in a hot climate so this is a more challenging application than, say, for someone living in the northeast.