Car Diesel Motor For Rubberduck

Hi all,any one who has done this before,i would like some tips,want to install a 1900cc tdi volkswagen diesel round about 73kw or 99hp in a 5m rubberduck of +- 300kg and it can carry 6 people,my plan is to do a direct drive thus i have to make most of my available 4500 rpm,what size prop and what about marinizing the motor??

 

The first question is what HP will you expect the motor to run at at normal cruise?

99hp no chance about 50 -maybe 60 it should work.

FF

 

Hi fast Fred,yeh those ducks recomend 50- 100 hp im not gonna run it on wot all the time and mostly only 2 persons on bord do u think the 1900cc tdi volkswagen will do the trick?? the diesel got the torque low down to get it on a plane and these small diesels are real gems,im driving a 1500cc tdi and it is nice fast and alot of torque it is a renault megane and i ve kept it at 4000rpm easily, thanx anyhow what about marinazing?

 

The problem is at road speeds you are only asking for a few hp. This engine will give less than 25 HP per gallon burned in an hour.

So if you travel 75 mph and get 40mpg , under 2 GPH consumption, you are burning about 40 -45 hp worth of fuel.

To maranize you will need to search for a transmission and drive plate to fit the VW. They may have a water cooled exhaust manifold too.

If no manifold is found , thats OK as good enough heat insulation on the manifold will work.

The next decision is finding a heat exchanger , a used one from a gas marinization will do fine,

To cool the heat exchanger a pump will need to be added to the boat. Most common is an engine driven , but I have seen electric units work just fine .

Finally the exhaust will have to be decided.
Probably a dry stack even with muffler would be to hard to live with , so a "riser" will be needed for the exhaust , so the cooling water can be dumped into the exhaust , on the far downside of the riser , to calm the noise and cool the exhaust.

FF