has anyone considered 12v or 4bt in boats?

[DerekW]

Hey I was just curious has anyone considered or performed a 12v swap into a boat? what kind of outdrive could you use? think about it you could add HP with the engine still in the boat. turbos, fuel plates, injectors, etc.



I have been achin to fab up a boat built around a 12v to play in the rivers around here. any ideas? anyone considered it? what kind of outdrive could you use? got any feedback?

 

[Allnew2Me]

I believe that TDR member SNOKING has a boat with twin Cummins but I don't remember if they are 12v or 24v.

 

[Bob4x4]

There have been Cummins powered boats for years,that's where we got many hi-po parts back in the day.



Bob

 

[PToombs]

JLeonard is getting parts to do a 12v swap into his boat. I don't know what it is, but I think it's a larger boat. He's a boat guy, and may have the answers for you.

 

[JLEONARD]

In 2000 I repowered a 34 ft single screw Mainship... from a 160 hp Perkins T6 to a brandy new 6BTA at 270 hp. Nice setup... made a whole new boat. 10 knot max speed to 18+.

Now I have a 40 ft trawler with a single Ford-Lehman 120 hp (natural).

I have a 6Bt out of an 89 pickup that will go in in a year or so. Right now I'm gathering marine parts/peformance parts. I don't want much power out of it... only about 200/220 which should be a piece of cake. I have a "jacket water" after cooler for it (antifreeze cooled like they put on busses) that will make it so 220 hp won't hurt longevity. (my 270 also had a jacket water aftercooler). I also scored a new set of 220 marine injectors for $100... . it pays to be patient.

The issue with marine aplicatins is the duty cycle. If you want any longevity you need to be conservative. I has to be correctly propped s it is not overloaded. Otherwise it will die a quick death. The pyro must be monitored... they do post turbo in a marine engine... the exhaust manifold is antifreeze cooled so there's nop place for a probe until after turbo... 800 ish is considered the practical limit. You can look up specs online and you'll see what I mean.

My boats have all been straight inboard... I really don't think you'll find an outdrive to reliably handle the Cummin's power. Inboard is simpler and sturdier anyway.

Try reading up in SERVER BUSY great forum for diesel powered boats of all brands... the Cummins threads are particularly good.

If you have any specific questions e mail me off line -- email address removed -- I've been around marine diesels for quite a few years.

Have fun with the project.

Jay

 

[mberry]

I have tried getting my friends to do a Cummins swap into a boat. One of them is considering a DMax for his boat. They are into jet boats, so power isn't really an issue for them for their drives.

There are several drives out that can handle the power and torque if you are conservative as JLEONARD pointed out. The Bravo 3 is one, and many IMCO versions can handle it too. My preference would be a 3 stage Hamilton jet or something similar.

My dad has a Boulton jet boat and I've been trying to get him to convert it to diesel power. I'll try and get the name of the company, but they build those types of boats with up to 6BT powerplants from Cummins-Mercruiser, Yanmar, and some others I can't remember.

 

[Canadian Cummins]

Cummins marine

Check out thier web site, Cummins has been in partnership with Mercruiser for some time with small diesels to huge marine diesels,

This link will get you to the QSB9. 5 series

Marine Live-Cummins Marine

There are other drives that are on the site one is a twin, thru hull z drives with joy stick control for 360 digree sterring control.

Like it was said before cummins has a lot of go fast goodies from the marine side, one thing to think about is to change the camshaft if ur going to be upping the HP as the truck engine power band is built to cover a wide rpm range, a marine engine usually is made with most power at the cruising engine speed not much on low end. made to sit at 1900-2000rpm all day.

CC

PS I am a certified boat builder of wooden boats but now work in the aviation industry, from on the water to into the air;-)

 

[pvanwig]

Diesel Baywatch

Our 30’ rescue boats carry two 300 hp 6Bs direct drive with a 4B for the fire pump.

These are heavy wood boats not light fiberglass.

We started building diesels in 1990 for Baywatch 16 and re-powered the older boats so that all are done now except one that requires too much modification to do for such an old boat.

The change raised our top speed from 20 to 30 knots and cut our fuel cost to half. With great towing power

Baywatch 19 has new 24 valve common rail 6. 7L motors to be installed but waiting for $40k for new trans, struts, shafts,props & mount changes

 

[m1ashooter]

the QSB5. 9 and Hamilton 274 is a popular combo in tour jet boats, most diesel boats are Yanmar powered. There was a 23' jetdrive, 4. 2 CXummins, the one mercruiser sells coupled to a Hamilton 213, was the first one of it's kind, but it went to the great boat yard in the sky after the insurance totaled it last fall.



If you are interested in reading more, Precision Weld jet boats and Bentz jet boats are the high end players in the PNW market for diesels...

 

[EDankievitch]

I'm just about to start my next Diesel boat conversion. I did a Volvo D3 in a 21 Trophy with the SxDp outdrive. The boat was a home run 20 knot cruise burning less than 5 gal per hour and very quiet. If any one is looking for a great boat it's up for sale. Drop me a line at -- email address removed --. For my next project I'm looking at a 29' Fountian Sport Fish, I'd like to instal a 5. 9 Cummins with the Bravo drive. I'm looking into sorceing parts and an engine. Should be a fun project. I'll post pics when it gets rolling...

 

[MAD JAX]

"Arneson" is the answer ; )

The Bravo's will not hold up to Diesel Power/Torque... but the Arneson Surface Drive will easily, and they're less expensive than any "Bravo" style drive that may otherwise.



I've got a '80 Formula 302 I've been working to retro a Single Duramax into, and I'm using an Arneson ASD-6s (Actually the original "Stepped" Model #1721 Borg Warner)



Check 'em out here:



Arneson Surface Drives



Notice the "Bravo Conversion"... You'll be needing it if you're to put any measure of Diesel Power into a boat that's only got a Bravo on it ; )