Undersized Motors?

PickleRick

I am currently exchanging emails with an outfit in Germany that produces the marinized exhaust manifolds for the om606 mercedes 3.0 diesel motor.  In a marine app these are best run 3500 rpms or less for life span and kept tuned 200 or less hp.  They are 3.0, the turbo versions have oil squirters and parts beefy enough internally to handle 250+ hp in street form(hp comparison to a 4bt Cummins but with some 300 lbs less weight and a broader torque range, the shorter stroke allows more rpms)  im looking at a marine hx40 turbo counterpart from a Cummins to install on it. Not ready to pull the trigger just yet but im brain storming.  The chipped ecu will allow me to make adjustments to get optimum performance and mpgs out of the set up based on my final turbo and exhaust set up.

What rpm are you diesel guys with stern legs running at crusing speeds?  Say @25 mph?

Ideally youd like to cruise sub 3000 rpms, say 2800 rpms but that is trawler rpm and if i wanted a trawler id have bought an old 2670 bayliner explorer not a get there fast if you want to rinker.  I've heard many complain about no steering or squirly steering at idle no wake speeds but even with a busted off skeg i get none with trim tabs all the way down.  The only exception is after a hard rain my bilge fills, my rear bilge is auto only now and its not wired for a manual pump so she'll hold several maybe 10 gallons before activating the forward engine compartment bilge(2 bilge pumps in my engine bay because i don't care about c8 vetts) 

I will wire in the manual switch this winter. Was 95 degrees yesterday, still too hot for crawling around in the engine hatch and snaking wires around.

Liberty44140

Hey Paul, any update on your performance issues?

zaverin1

I am going to try and see Paul this or next week.
if engines are tuned up and everything is serviced it could be just weight distribution.
i mean it could be the bottom or the props lol but I can start with the basics.
he has mpi engines with bravos and I had carb twins with alphas.
my 280 never had any issues but mind you I am a freak when it comes to maintaining everything I own.
i had 9 adults and she would still plane and go.

PickleRick

If i have 9 adults aboard any of my boats its time to make a few walk the plank...unless they look good in a bikini.