As a long time former I/O guy, I get the desirability of a big block sound, but for me and being that we do all of our boating in saltwater, the reliability of outboards wins over the sound.

Haven’t seen an OB cat do 140 yet, lots are close though. Probably out there already.

The 64 degree bank angle means they don’t exactly have the classic sound.

Interesting info from everyone. Thanks.

I wonder if Merc would ever use the outboard blocks to build I/O motors.

i just watched a video from a captain coach or coach captain on a run he did to move a 40 plus foot valhalla from irc Miami to marco island
it had four mercs on the back and at 47 to 50 it was burning on the range of 61 gallons per hour
it was something
https://youtube.com/shorts/hLRTritv6-I?feature=sharedhttps://youtube.com/shorts/hLRTritv6-I?feature=shared

It would be too expensive. The benefit of I/Os is that you can use ancient, simple, GM automotive engines built at high volumes and low cost, paired to a drive.

Back in the days when Volvo still had a car division, they used GM engines instead of their modern in-house 4 valve engines for I/Os.

False,
Before the OMC merger/ acquisition, there were thousands and thousands of Bayliner Capri’s just to name a few, that were equipped with 4 cylinder cylinder Volvo engines.

But weren’t those the seventies B20/B21/B23 4 cylinder designs?

Brunswick, not OMC, acquired Bayliner in 1986. Volvo’s 4/5/6 cylinder 4-valve engine platform was launched in the early nineties. As far as I remember, those engines were not marinized. Volvo Penta used GM V6 engines instead.

Funny what threads bring the lurking OG's out to post, good to see you're still around...................I say long live the IO's