Mercury I/O Diesel

Slow Roll · 09-23-2003, 12:46 PM

Found this awhile ago thought is would be an interesting upgrade/retro for those who are looking. Don't know if it is on the market yet or not.

Popular Mechanics

This article gives a comparison between a gas I/O, gas outboard and a diesel I/O.

Just some food for thought.

Paul B.

Steelhead Hound · 09-25-2003, 12:34 AM

WOW!!! I HAVE NEVER HEARD OF THAT BEFORE....I DON'T THINK IT'S ON THE MARKET YET.....

Sea Jypzee · 09-25-2003, 05:19 AM

Very interesting. Looks like they're definitly moving in the right direction with this.

Master Baiter · 09-25-2003, 07:25 AM

This engine has been available for a couple years...

Orca · 09-25-2003, 07:32 AM

When I was at Winchester Bay a few weeks ago, diesel was 1.339. When you aren't paying all the road taxes, the price is pretty good. That is why I can't figure out why gasoline at the dock is so dang expensive. Somebody (the ports, and cities?) has their fingers too deep in the pot.

Gregotis98 · 09-25-2003, 07:57 AM

Seems like 170hp diesel turning 4,400rpm is a little much. My dream boat is about a 28ft walkaround with an inboard diesel with at least 200hp and is still trailerable for about $15,000 [img]graemlins/dork.gif[/img] .

I keep thinking of ways to adapt a reasonably priced truck or auto diesel into a boat. If only the Mercedes 5cyl diesel from the 80's spit out more than 140hp.

fish assassin · 09-25-2003, 08:30 AM

Gregotis,

Heh! Don't want much, huh? :grin: :grin: I've got the 250 hp MerCruiser diesels in
my boat and each of the engines with outdrives cost close to $20k *each*! ... And
those are the VM engines (built by an Italian subsidiary of Detroit Diesel), not
the higher quality of the 120hp Cummins ... BUT, a good dream, none-the-less!

Miss B Haven · 09-25-2003, 08:32 AM

Gregotis- most all marine diesels are marine conversions of truck/auto/tractor/equip diesels.
Cats/Detroits/Cummins/Volvo/yanmar/Lugger (John Deere blocks)/John Deere/etc etc etc.

The bad news is that 15K proly won't buy you the conversion parts let alone the boat/base engine. Heat exchanger/marine tranny/tranny cooler/wet exhaust manifold etc etc.

PS- I don't consider these small displacent, high speed diesels as real marine engines. My cats are fairly high speed (2800 rpm top). Although they only put out 300 hp, they are close to 900 foot lbs of torque. Compare that to the torque on these high rpm engines of the same hp.
These high speed diesels won't last much longer than a gas engine, wear and tear at 4400 rpm is way more than double running at 2200. I woudn't expect to get more than a couple thousand hours out of the high rpm motors (compared to 5 or 6 thousand on a low speed before rebuild). (IMHO)

fish assassin · 09-25-2003, 08:46 AM

Mel,

The biggest difference between engines like you have and (say) the Volvos that
run at higher RPMs is that YOUR engines are 4 stroke diesels and the Volvos are
2 stroke diesels. The 4 strokers will last longer at the same RPMs than the
2 strokers, the way I understand it. BTW, my 4strokers are actually a high
RPM engine with a top end of 3600 RPM. However, I usually don't run them over
28-29 hundred so they will last a little longer (I hope).

That was one of the main reasons I went with the MerCruiser (VM) engines instead
of the Volvos. Expected longevity before a rebuild was better. Guess I'll just have
to wait and see how it all works out. So far over the past two seasons I have *only*
logged about 950 hours. At that rate I figure I probably only have 9 or 10 years
left before I'm going to have to go for a rebuild!

:smile: :smile:

Miss B Haven · 09-25-2003, 08:50 AM

FA- I wasn't aware that ANY of the diesels these days (since the old Detroit smokestackers) are 2 strokes. As far as I know they can't make emission requirements for road use. However- those little volvos they sell do have blowers on them as well as turbos. Blowers are usually a two stroke thing. Never really considered that. :whazzup:

Sensei-san · 09-25-2003, 08:56 AM

Fish Assassin, I don't think the Volvos are two stroke. The only two strokes are the Detroits and they have formed a partnership with MAN to get four stroke technology to replace the two stroke engines.

All of the more modern diesels have to meet IMO standards. That is why CAT dropped the 3208. They couldn't get it to pass the IMO standards. even more strict standards are coming. California passed a catalytic converter rule for diesels and marine gas engines last year.

But diesels are the way to go for marine power. Diesel fuel has a higher caloric value than gas and is far less explosive as a fuel than gasoline.