I have a very low hour D722 circa 2000. It was in a small skidsteer but was way too much engine so I'm going back to a small gas motor and have this pretty much new diesel. I'm building a 26' dory for which I bought a new 4-stroke outboard to mount in a well. But with this little diesel in my lap, I would much rather have it in there.
So what should I expect to have to go through to put this in a boat?
The answer to your question somewhat depends somehat on the specification of the D722 in your skid steer, but yes, it can be done.
Beta Marine specification of a D722 is for a 'back plate' engine (no flywheel housing) The following are them some of the items we add to the base engine in the marinisation process.
Heat Exchanger / Water Cooled Exhaust Manifold Thermostat Housing Raw Water Pump Raw Water Pipework and Hoses Exhaust Elbow with Raw Water Injection Bell Housing (to suit a Marine Transmission) Flywheel + Inertia Ring Flywheel drive plate to suit Transmission Input Shaft Bracket to support Morse style cable fitting for Transmission Bracket to support Morse style cable fitting for Throttle Throttle Actuator Arm Engine Mounting Brackets Engine Mounting Feet Engine Mounted Fuel Filter Wiring Harness Instrument Panel
Also used, but dependent on installation clearances in certain boat hull, we use a shallow cast aluminum oil pan and use alternative dip sticks in different locations to aid engine checks.
We also change Inlet Manifolds, add Oil Change Pumps as required by our build specifications. So you can see, we start basically with a long block and build from there.
We can assist you in the marinisation of your engine, but we need to discuss the configuration of your D722. I would suggest you call us on (877) 227 2473 and we can discuss your needs and the associated costs.
I would also point out that the D722 will probably be too much engine for a 26' Dory.
Here's my take on the power, since this is a discussion board presumably:
Kubota lists the D722 (continous) at 16.3hp @ 3600 and 13.8 @ 3000. I like the 3000 just fine. I see the chart from Beta's site on the Kubota site as well. There is about a 3% loss in the gear unit and 1.5% per bearing. So we're down to about 13hp, continous at 3,000rpm. According to David Gerr's book that would push a 3,500# dory at 10kts with a real 14" prop. It's a Glen-L design and they say it will do 10kts lightly loaded.
I see where you are going, but be careful, working with the absolute nett output of an engine can be risky.
Our expertise is working with displacement boats, not planing types. When working with a diesel engine we concern ourselves more with the torque and the multiplying effects of a reduction transmission where the transmission ratio and the propeller size are more important than the horsepower.
I would suggest your best approach would be to refer to a 'prop shop' that has experience with this sort of application. Even then, expect to do a bit of 'tweaking' to optimise the performance.
