Rbesola

My question (and not saying i want to do it) is has anyone really played with putting diesels in a performance boat? Wether it be a light duty motor or heavy duty. Would the the stringers survive the weight and torque? I've alwasys thought built 450ish HP 6.0L Powerstrokes in my Top Gun would be wicked. Or a couple 550+ HP 6V92TT screamin Dertoits. Maybe 3208T Cats? Just seems like they would be the answer to fuel economy and reliability and speed mated to some variation of surface drive? Able to run an air/water IC with endless cold water. Throttle response isn't needed. I've built a few HP Cummins and theyre just so simple to diagnose and fix its crazy (although I've yet to have to).

ondtip

Weight is a big problem. Also most diesels don't rev as high as gas engines. With that small of an RPM range it is really hard on the drives.

1987pachanga22

It seems to be fairly popular European countries. I also know of a Nordic 21 heat running a cmc diesel and duramax transmission but that is not realy an offshore performance boat.

mcollinstn

There have been plenty of diesel installations in 42' plus performance hulls. They are indeed stressful on drives, and usually end up running rugged surface drives (or in a couple of boats I've seen Merc Six drives behind a diesel). You definitely DON'T get the same power to weight ratio, but you do reap the benefits of the more economical diesel and incredibly long design life.

For some, RANGE and reliability is more important than absolute top speed, and diesels excel in that arena.

Tell me the last time you saw a 55' sportfishing boat with gasoline motors. You won't see it. 800 to 1200hp diesels is the norm in those babies, and some of those boats run well over 40mph.

High performance diesels are expensive, though.

I saw a few pallets of marinized DuraMax diesels on the floor at MTI a couple of years ago that were due to be installed in a customer boat. I believe they were somewhere in the 600+ hp range and were going to be feeding some Merc sixes. They were NOT Banks motors, but Banks does offer a marinized Duramax in flavors up to 575hp. I never heard of how that boat ran, but it was supposed to run around 120.

Fountain sold a good number of 48'ers with Yanmar diesels and surface drives (420-450 hp). I knew of one that had a little "tuning work" done on it that would run 70 and delivered almost 50% more range and fuel economy than a gasoline powered version with a similar cruise speed.

As far as hotrodding your own diesel, the 5.9 Cummins has been offered in marine flavors up to 480 hp. I assure you, though, that this motor has different internal components than the 5.9 you would pull out of a Dodge 3/4 ton. HEAT is the big equalizer. Since a boat has unlimited cooling options, you can get rid of heat in a boat easier than you can in a truck. BUT you still have to figure on higher volume oiling systems, large oil coolers, giant heat exchangers for the coolant, giant aftercoolers, giant waterjackets on the turbos, giant watercooled exhaust elbows. Internally, you have upgraded oil squirters on the undersides of the pistons, different injectors, and other beefed up hard parts.


Marine diesels in the upper hp ranges are well engineered, and well thought out. Turning up the fueling curve and boost pressure on a 4x4 truck motor won't really net you as good of a result than starting with the correct marinized package and then doing some upgrades.

But don't plan on trying to make a Bravo live behind a warmed up diesel. You'll be smelling gear oil and paddling.

MC

Unlimited jd

iTrader: (5)

Don't ever consider a 6.0 power stroke for a reliable engine. Might as well mate it to an alpha and take turns guessing which will leave you stranded first!

MILD THUNDER

iTrader: (3)

Well at least fixing headgaskets would be easier in the boat!

I know everyone loves the diesel stuff these days with all the chips and programmers and stuff. However, in a boat, idling down the river with thru hull exhaust, I dont think i'd wanna be smelling diesel fumes blowing in my face while im trying to drink my pina colada and eat some pineapple. Not to mention the limited RPM band, you have to run such tall props or gears, the setup kinda just sucks for a offshore boat. Diesels work great in big cruisers, low rpm workhorses.

Personally, rather than a couple cummins motors in my top gun, I'd take a set of 600CI big blocks with Roots blowers making 1000+HP a side anyday with dry pipes for a cool factor. 1000+ft lbs all day, that 6.0L powersmoke will puke it guts all over your bilge trying to withstand that for 50 miles straight in a poker run. The EGT's would probably melt the cylinder heads and exhaust pipes.

You boat down on the River, Hook up with Mike Tkach down there next summer, and have him take you for a ride with his twin 1200hp whipple blown 588's in his 38 Fountain. If you like torque, those will put you in your seat. Stringers hold that 1200FT lbs just fine.

keith2500hd

realize that diesels make lots of torque, don't get hung up on hp numbers and work on continuos power ratings. i would look at arneson drive and duramax with allison(eaiy to tune and load control) PPE has setup in nordic, go to their site. look at european boat builders they run lots of diesels. mercury, cummins marine diesel(cmd) list various engines. the smaller engines are VMMotori(sound familiar to engine banks working on) stay away from old heavy engines unless you desire durability. a company out of st louis bought old tommybahama boat put 2 6-800hp duramaxes in it. made lots of nice parts(dry sump pan) last time i saw news they were waiting for hugh 36x6 surface props to try and load engine. i had customer that had CMD 4.2 200hp in hugh 26ft x9ft plate boat with cabin, it would go over 30mph with groceries(midstream supply boat). the 4.2 is similar to 5.9 in appearence and picked by BMW for their drive package in early 80's. Iveco and Isotto-Franchetti also ran race boats here in early to mid 80's. new Variable Vane turbos can be adjusted to cleanup exhaust, a benefit of newer diesels. good luck.

Sydwayz

iTrader: (1)

There is already a very long thread on this. Perhaps someone could bring it to the top?

Rbesola

Only reason i bring up diesels is Pier 57 has or had a 2003 42 Skater with 720hp Seatek's they claim 90mph cruise at 4mpg?!?!?!? Sounds way too good to be true. At that point I'd have to consider giving up the big blocks. Don't get me going on the 6.0L. Lol. I wouldn't trade mine for anything on the market today.

Rbesola

I searched.Maybe ill have to look harder