Air cooled inboards

[Peter Jacobs]

Thinking about inboard engine possibilities for the Folkboat: There seem to be some small lightweight air cooled diesel engines available.
http://www.hatz-diesel.de/index_e.htm
http://www.islandnet.com/~pjacobs/1b.jpg

What I'm trying to avoid is having an outboard hanging off the stern, and having all the water cooling paraphinalia of a regular inboard. A little noise would be OK on an engine that will run about 10 hours a year.

What thoughts on this one?

-Peter-

[ 06-08-2002, 12:37 AM: Message edited by: Peter Jacobs ]

[Aramas]

A lot of people have done it. The cost and weight is a *lot* lower than a marine diesel. The main design problem is shared with turbines, ie. getting a high volume of air through the engine bay without letting water in. Also, like any aircooled engine, large doses of water can be catastrophic.
They're popular on asian 'longtail' riverboats, that that's not much help for a folkboat.
You would need to seal off the engine compartment to control noise and heat, then build 'Dorade' vents for both the intake and outlet. Additional blowers may be required depending on how effective the standard air cooling is. You can eliminate the waterproof intake by taking air from the cabin at the expense of added engine noise. Dry exhausts are not really a problem, and have been widely used on fishing boats for ages.
I guess you'll have to weigh the not insignificant additional labour of an air-cooled installation against the added expense of a water-cooled system. Good luck smile.gif

[Ian McColgin]

My Deutz is air cooled. I have ducting leading from various places in the bilges to the intake side. The outlet is ducted to a louvered vent outside the cockpit. Given Grana's size, this has never taken hard water, but I do have a fittes snap on cloth cover to seal it against driving spray and rain and snow, though given the layout of all the venting and the materials, I've never worried about water damage. That, however, might not be true for your unit.

There is no way to make an air cooled engin very quiet - engin noises come out that vent. I've thought, when I rebuild the boat, of making a combo exhaust and hot air exhaust verticle stack that's sound insulated on its walls and is high enough to shoot the noise straight up. Figure to have the engine and cooling come it at right angles and have a kind of drain bowel to an overboard (above water line) so's not to worry about the rain, though I'd have a tampon to stick over the stack when not in use.

G'luck.

[Amber1]

Looks like you could easily unbolt it and take it home for the winter like an outboard. The specs from Hatz list the required amount of airflow. You could easily meet the airflow requirments with a properly sized bilge blower. I think the Coast Guard may be ok with air cooled deisels.

[Paul Scheuer]

Anybody got any pictures ? And what are we talking pricewise for enough to power a 23 footer, presently ok with a "Sailmaster 8" outboard. Others have used Yanmar 1GM10. . . .

[Downwind]

I installed a Mase generator in my boat which is an air cooled Yanmar one cylinder diesel driving a generator all enclosed in a sound shield. The air is recirculated and passes through a small sea water cooled radiator within the sound shield. It works like a charm, is quiet running and when the engine finally goes, I will simply unbolt it and go down to the lawnmower parts store and get a new one!

[Peter Duck]

G'day Peter, The only contact that I have had with an aircooled diesel on aboat was on a fishing boat operating here in southern Oz. The engine was a Lister,which drew its air from the cabin, and blew it out through ducting to a vent just in front of where the helmsman stood. He was one lovely warm fisherman! You could also duct it through a drying locker, given that it's easy to get your kit wet when you're on a boat. In a cool climate it has a lot going for it; you might even end up using your boat for a little more of the year because of it!
Peter.