HK wrote:

Serious question. I have no ownership experience with these modern, car
or truck gas engines in boats. What RPMS do you typically run them at?
My SUV V8 loafs along at 2000 rpm or so at highway speeds, but you have
to be running at what, twice that, in an I/O planing boat. What steps
are taken to build up these engines to take that sort of constant high
rpm stress?

Basicly there's not much difference between the automotive and the
marine versions of the engines. With exception that the I/O people
will select the heavier built engines that are used in pickup trucks
(thicker block webbing and 4 bolt main bering caps, Steel crank
shafts) but outside of that not much. Oh, the marine versions use a
different cam shaft than automotive and thats only to put the maximum
torque in a more suitable rpm range.

I run my 3.0 GM 4-cyl. at about 3300 RPM and the 350 GM v-8 at about
the same rate. Get up on plane than back it down to maintain the
plane. I don't run wide open. except to get out of the hole. But
both engines are capable of pulling 4000 rpm safely and sustained