Engine Cooling

Steve, I read with marvel at the thought that you put into your systems. I also spend far too much time thinking about systems and I know of nobody in the industry that has it to your level. I’m just surprised about one thing…engine cooling. You go to great lengths to cool your AC and
refrig. using the “internal keel coolers” in order to eliminate all of the saltwater usually associated with it, but what about the engine? Why not
keel cool that? I have always felt that the weak point of these engines is
the belt driven rubber impeller pump and all of the intakes, strainers etc.
associated with it. I know that you are going to say that it adds heat to
the engine room, but my Nordhavn 40 was really quite cool with a keel
cooled dry exhaust engine. With an aluminum boat, you could even cool
through the skin.

An even better solution comes from the late Phil Bolger. He once drew a
unique boat that used an oil/air cooled Deutz engine. If you are not
familiar with it, these engines don’t have antifreeze as their coolant.
They curculate their lubricating oil and air cool it in order to cool the
engine. To me, it would be the ultimate…get rid of all of the usual
things associated with heat exchanger cooling and even eliminate the
complexity of a keel cooler….heck, they even eliminate an entire
fluid…antifreeze. Are you familiar with these?

One other unique engine that could be nice for the new 64 is these Steyr
engines that have an integrally mounted electic motor/generator. During
normal operation that generator could supply all of your DC needs without
needing an additional belt to drive it. In an emergency, it could be
driven as an electric “get home” motor powered off of the generator. I
think this could be a nice solution for a single engine boat.

Allan Salzman

Hi Allan:

We have given the wet exhaust Vs. keel cooled lots of thought, and go into this in detail elsewhere on t he website. The bottom line is that there are maintenance trade offs with both systems. Wet is quieter, gets rid of condensation issues, eliminates hot stack fire risks, and is much cleaner. Part of the answer is having an easily accessible gear driven raw water pump, dual large capacity strainers, and a system for easily clearing debris from the raw water  intakes. If you replace the raw water pump every 1000 hours (and then rebuild it) you are ahead of the maintenance cycle. The Steyr engine with genset built in is interesting, but we much prefer the Deere engines for their known qualities and world wide service.

Posted by Steve Dashew  (December 10, 2009)

3 Responses to “Engine Cooling”

  1. RayG Says:

    Yanmar now lists a between the engine and transmission generator set (230VAC 50hz) for their 3JH4E (39mhp) or 4JH4-AE (54mhp) diesel engines. http://www.yanmarmarine.com/index.cfm/go/Accesoires/
    Too small for FPB’s. Maybe it would fit on or they will come out with gen sets for a large enough engine. But 54hp is a good sized sailboat engine.

    FPB 64 John Deere 6068TFM w/ZF 280 trans, Yanmar lists ZF trans, as does Steyr. Wonder if you could put the Yanmar or Steyr gen set between the JD and it’s ZF trans?

    Fair winds and may the God that calmed a storm with a few words watch over your voyages,


  2. Steve Dashew Says:

    The Yanmar and Steyr in line genset is a fascinating concept for sailboat systems as you have noted. For the FPB 64, given the need for 100% reliability, and the higher AC power requirements than most sailboats on wash day, the output is a little low and the hardware too new. Our approach with the big Electrodynes, traction batteries, and inverter stack costs a small fortune, but has proven totally reliable. The 64s have the 11kW genset as well for high load periods at anchor.

  3. Joshua Kout Says:

    Is it possible we are interchanging a Diesel/Electric Series hybrid system with the term generator? Ive not looked too close but it seems the Steyr rig is designed as a hybrid drive. (not diesel/electric)