ISB Marine Conversion

[zippinbye]

Check out this site (http://www.cmdmarine.com/PDFs/4081940_0205.pdf) for the spec sheet on the "Cummins MerCruiser Marine QSB5. 9 ES 230. " The engine is a said to be the same as a 2005 Dodge Truck ISB, mated to a Mercruiser Bravo II-X Drive (Mercury Marine's heavy duty stern drive with one prop). It is rated at 230 h. p @ 3000, 510 ft. lbs of torque. Seems to have some nice controls and features that take it beyond simply bolting a truck engine to a gasser outdrive (although the 1. 50 ratio is an available ration for gas engines). The spec sheet says the U. S. Navy is using it in a 7 meter rigid hull inflatable boat. Based on a ride on a similar vessel powered by 115 Yamaha, a CTD would make for an exciting ride! I digress. I'm more interested in powering a 27 to 30 foot trailerable family cruiser with a single 5. 9 sterndrive. Obviously the CMD Marine set-up would be great, but without even inquiring, I know it's out of my price range - I'd guess more than half of an entire 2006 Cummings Dodge truck. But a salvaged truck Cummins 600/610 paired with a similar-source Bravo II might be a cool drive system. Is anybody aware of any engineered marine conversion set-ups?Engine control, cooling, air intake and drive coupling are a few of numerous issues that make such a swap anything but "bolt-in. " I know of similar swaps with a Duramax and 7. 3L Powerstroke, but have never seen or heard of a Cummins 5. 9 in a boat that was not already a marine engine.



Thanks for any tips you could offer.

 

[BILLUA]

Do a Google under "boat gas to diesel repowering"... You will find several articles and real world experiences... One guy said it would take him 20 years to recoup the costs...

 

[JLEONARD]

There is an outfit in Texas, H&S Marine or something like that that sells a "marinizing kit" for the 6BT. It includes the cooled exhaust manifold, marine turbo (HX35M), aftercooler, etc. I think it sells for about $5k or in that ballpark.

General thought is that up to about 250 hp it will be reliable in marine application, but above that forget about longevity. The marine base engines have some design features that the truck engines don't have. The higher hp marine engines have even more.

Lots of the external marinizing parts show up on ebay from time to time, so check there if you are serious.

I repowered a boat 5 years ago with a new marine 6BTA at 270 hp (standard inboard setup). It was an awsum engine, quiet, efficient, easy to work on, etc.

Only real PIA was the location of the seawater pump... . in place of the power steering pump and very hard to reach in a boat's bilge.

Hope this helps. Have fun.

 

[boaterdan]

H&S Marine has a web site - www.hsmarine.com.



They mainly go into straight inboard applications. I would suspect they could accommodate a sterndrive.



I'm on the downhill run of a boat restoration that is going to have 2 24v engines with their kit. I'm hoping to have the boat in the water in the next couple of months.



Daniel