Larry Smith (Scarab) and Randy Scism (MTI) on diesels

[ECeptor]

...both were interviewed in separate magazine articles. Both mentioned diesels as the next wave of low maintenance, high efficiency for performance boats.
Scism had a big cat (38', I think) with twin Yanmars that ran 100+, burned 1/3 the fuel of blown BBCs, and had rebuilt intervals in the 1000's of hrs vs 100's of hrs for gas engines.
Smith in a separate article talked about the same benefits - lower fuel consumption, much longer service intervals and more reliability vs the current state of the art gas engines.
So, what does everyone think about diesels in high performance (non-race) boats? Anyone seen any +70mph oil burners on the water?

[HOSS]

Yeah, the Navy MK-V aka Mark 5. We had one at 78!

[Lightning]

If they offered a diesel engine I would seriously consider it. The only problem is lack of diesel fuel availability on the water.

[scarabrick2]

It's going to take a BIG boat to handle the weight of the diesel. Oh yah and a lot of HP/torque. maybe a coulpe of in-line 6's with 1 turbo each would be ok but it needs a lot of engine room. Diesels have a lot of torqe so the drive would have to be a surface drive(direct drive,v drive) we had a work boat with a diesel/volvo drive and man that thing ran forever. did great on fuel but was a$$ heavy with only one in-line 6! All you need is extra fuel filters and a manual priming pump and your good to go.

[Jordy]

The only problem is lack of diesel fuel availability on the water.
If you're on the ocean it's everywhere. On inland water, it would be easier to find than race gas, and if you're not burning as much of it, just fill up before you dropped it in the water and run all weekend.
Also, you'd be able to run red-dye fuel which is cheaper because it's an off road vehicle. ;)

[LHC30Victory]

Aren't the newer diesels lighter lately due to newer metals? If they keep working that angle, then between the higher torque output per displacement and the lighter structural components, it may become quite popular. Besides, a pair of straight sixes would free up a lot of engine compartment wouldn't it?

[HOSS]

Mark 5`s a jet driven.

[superdave013]

I was talking to a guy at the last PRI show about his diesel project. He's doing up the Duramax for a direct replacement for the 496. He says he can make over 1,000 ft/pounds of torque all day long. I asked how many hours it would live. I can't remember what he said to the T but it he is expecting way way more life then you'll ever get out of any blown engine putting out that kind of power. And yes, no race gas, no av gas, just fill it up with diesel.
It should be interesting to see what happens with it.

[scarabrick2]

Aren't the newer diesels lighter lately due to newer metals? If they keep working that angle, then between the higher torque output per displacement and the lighter structural components, it may become quite popular.
Besides, a pair of straight sixes would free up a lot of engine compartment wouldn't it?
I think we have a bigger sun pad with the diesels(longer than gas). Even room between the motors for a dance poll!!

[Jordy]

I was talking to a guy at the last PRI show about his diesel project. He's doing up the Duramax for a direct replacement for the 496. He says he can make over 1,000 ft/pounds of torque all day long.
Before I went the route I did with the whackers I was considering finding a Cig without power and throwing a pair of Duramaxes in just to do something different. The weak link with 1,000 ft lbs of torque would be the drives so it would have to end up with #6's or Arnesons to live. Started penciling some numbers and decided that it was too much of an undertaking for an experiment, but none the less, it would be cool to take off and leave a big school bus style cloud of black smoke behind. :D :D :D

[scarabrick2]

Direct drive with crash boxes is the way to go :D Reverse, we don't need no stinking reverse! Just turn the motors off and coast in

[ECeptor]

I was talking to a guy at the last PRI show about his diesel project. He's doing up the Duramax for a direct replacement for the 496. He says he can make over 1,000 ft/pounds of torque all day long. I asked how many hours it would live. I can't remember what he said to the T but it he is expecting way way more life then you'll ever get out of any blown engine putting out that kind of power. And yes, no race gas, no av gas, just fill it up with diesel.
It should be interesting to see what happens with it.
I've looked a little into availability and price of D-Max and P-Stroke crate engines and there is a gap between them and gas engines...for now. I certainly think there is a market for what this guys is selling!

[LHC30Victory]

it would be cool to take off and leave a big school bus style cloud of black smoke behind.
Wouldn't the required mufflers take care of that smoke or would that be a NEW regulation????? :boxingguy

[Dave C]

that sounds like an interesting project.... plus the black cloud would be a bonus.... :D

[Jordy]

Wouldn't the required mufflers take care of that smoke or would that be a NEW regulation????? :boxingguy
That would have to be a new regulation I'm sure. I've never known a muffler to supress smoke, only noise. Besides, running through a turbo would certainly quiet the engines down to a legal level if I had to guess. Ever been around the twin turbo ski race boats? Most of them are surprisingly quiet at idle because of the turbos. ;)

[jackpunx]

we all have a friend that is working on a secret project with these motors in them.. I was told you can tune alot of the smoke out..
about 3-5 months and we'll see one of these on the boards :)

[Riverkid]

My buddy is buying a Baia 63' Azzurra express boat. It's the same boat that was the start boat at Catalina last year. It's got twin 1300 MTU V-12 diesels in it and Arneson drives. They took a sea trial a couple weeks ago and he noticed up in Malibu they were outrunning cars on PCH... After filming the 35' high 150' long rooster tail coming off, he panned over to the GPS - 58MPH in a 63' boat...

[scarabrick2]

http://www.teamscarab.com/kona-perf-cruiser.htm

[Steamin' Rice]

I was able to go for a ride in the Larry Smith boat with diesel power a couple of year ago in San Diego Bay. It was a little strange riding in an offshore boat that sounded like a school bus, but it was impressive. I think there were about 8 guys on board and we hit about 75 MPH fairly easily. This was the same boat that made the run from San rancisco to Marina Del Rey.
http://www.scopeinfo.com/images/2003-San-Diego/100KONI-PICT0685_PICT0685.JPG
http://www.scopeinfo.com/images/2003-SCOPE%20-Poker-Run/DSC00620.jpg

[BADBLOWN572]

Jordy is right, the weak link is an outdrive. Especially when you put some power to the engines. A D-Max can put out some 500h.p. and an eaxy 850 ft/lbs of torque with minor tuning. The torque is something that will kill outdrives. You will need to step up into something above and beyond which is going to be pricey. That is the biggest thing that is the problem.
Right now people can get gas motors that will be a lot cheaper and will run faster than the diesels. When the diesels can be doen for the same price as the gas engines and run the same speeds, then people will start opening their eyes and considering diesels. I know I would.

[ECeptor]

Jordy is right, the weak link is an outdrive. Especially when you put some power to the engines. A D-Max can put out some 500h.p. and an eaxy 850 ft/lbs of torque with minor tuning. The torque is something that will kill outdrives. You will need to step up into something above and beyond which is going to be pricey. That is the biggest thing that is the problem.
Right now people can get gas motors that will be a lot cheaper and will run faster than the diesels. When the diesels can be doen for the same price as the gas engines and run the same speeds, then people will start opening their eyes and considering diesels. I know I would.
I think two other factors will help swing people in time - fuel economy and maintence. A diesel done right is bullet proof...will run for 1000's of hours without touching it. That, to me, would be worth a lot. But then again, I just spent 6 hrs today wrenching on my 454 so maybe it just seems more important now.
I do like that Kona with the twin 5.9 420hp cummins...nearly same engine that is in the Dodge trucks and tons of construction equipment. That is bullet proof engine for sure.

[Jordy]

p.s. Along with the Detroit Diesel/Allison side of things, we're also the MTU and Yanmar dealer around here. :D :D :D

[pixrthis]

The advancements in diesel pickups makes diesel performance boats seem like a reality. After having a diesel truck I'll never own a gas truck. If it translates to boats the same way I think it could be the future. Drives and props will probably have to go through changes in order to deal with the low end torque.

[Forkin' Crazy]

I have a friend that is putting a Cummins in a 30' Warlock with an Arneson Drive. Should be interesting.
I was in Galveston Bay last weekend at a restaurant and some guy pulled up to the pier with a twin diesel powered unit. It was very quiet and just made a little smoke. The newer "quiet" engines should take care of the "rocks in a washtub" syndrome.
I don't think I would use a Duramax. Compare the rod size to a Cummins and you will see what I mean.

[ECeptor]

I don't think I would use a Duramax. Compare the rod size to a Cummins and you will see what I mean.
I work for a heavy construction OEM and know exactly what you are saying. Automotive durability standards are very different that off-highway and over the road trucks.
Anyone know the max rpm you can push a 5.9L Cummins?

[burtandnancy]

One of the magazines recently talked about the IMCO splitter: One high torque diesel and two outdrives. Divides the power, still give you f/n/r and good docking, lower weight and fabulous fuel economy. The splitter works great in Prime Marines ski race boat, just won the worlds with it.
There is also a company in Europe which makes a BB Chev to diesel replacement right up to the electrical plug ins and motor mounts. Lets face it, oil burners are coming...

[scarabrick2]

scarabRIB boats ( See my last posts), They have a single diesel with two drives. Check it out. It believe I'm correct

[ECeptor]

To stick with the single engine single drive set up all you need is a speed up gearbox between the engine and the outdrive. Would be damn simple to do.
Start with this 420bhp @ 3000rpm engine - http://www.cmdmarine.com/PDFs/4081898_0505.pdf
That's 735ft-lbs at rated rpm and 908 ft-lbs peak at 2000rpm.
Use a 1.83:1 speed up box on the output of the engine to cut peak torque down to 495ft-lbs while increasing the drive speed to 5500rpm. I think a standard Bravo XR could hand the <500ft-lbs and the 5500rpm.
The gearbox design would be a piece of cake. Down sides are there would be one more thing to check oil in and the outdrive speed might be too high unless engines idle was turned wayyy down.