Farymann diesel engines

[Gerry S.]

My sailboat's auxiliary engine is a 12 HP, one cylinder Farymann diesel. The boat is now 20 years old, and this is the original engine. The engine, which has an aluminum block, was designed specifically for raw water (i.e. sea water) cooling, and this is the way it has always been operated. It is still running fine, but I am beginning to wonder what the life expectancy of a raw water cooled engine like this is. I sail out of Vancouver, BC, and the boat is in the water 12 months per year. Our seawater temperatures are reasonably cool all year, which will slow down corrosion somewhat, but definitely not stop it. Has anyone had any experience with this sort of engine installation? I am developing a morbid curiosity regarding the proximity of the inevitable demise of my engine. The model of my particular engine is the A30M.

Thanks in advance.

[John Meachen]

I know nothing specific about Farymann engines but the aluminium based engines I have encountered have had anode protection.Does yours?For peace of mind it would be a good idea to turn all seacocks off when leaving the boat.Not a bad policy with any engine actually.

[Dan McCosh]

likewise don't know anything about a Farryman, but it would seem that an aluminum block could be engineered to last more or less indefinitely with proper anodic protection. Even cast iron lives 15-20 years or so with raw water cooling.

[Stu Fyfe]

I've had two Farymanns over the past 20 years in Redwing. I currently have the K34. It's a single cylinder, raw water cooled 5 1/2 HP engine. I've taken it out and rebuilt it once. I've also done routine maintenance that seems to keep her happy. A few things I've noticed. Every couple of years you should take the head off the cylinder and flush out the raw water ports. They accumulate sediment over time and restrict water flow. I would recommend that you degrease the valves and ports every other year. When you do this, be sure to replace the head gasket, rubber seals and compression fittings while you're in there. The K34 doesn't have any anodes. The zinc on the shaft must be replaced every year. I expect to get at least another ten years out of her, but I'm also keeping an open eye for a replacement if a suitable one should cross my way. By the way, my Farymann has a magneto instead of a generator. It hasn't worked for over five years now. So rather than replace it, I keep two batteries below and switch over as soon as one goes. Charge it up and start over. I'm considering a trickle charger next year.

[Gerry S.]

Thanks for the suggestions, Stu. My A30M doesn't have an anode either, but it is bonded to the prop shaft via a shaft brush. I replace the shaft zincs annually. My engine seems to be running cool enough at present, but if it shows any inclination to heat up under normal load, I will go through the procedure that you recommend. I always keep the seacocks closed when I am away from the boat.

My engine has an alternator. Stu, why don't you just put an alternator on yours? It shouldn't be too difficult to add another pulley on the front power take-off of your K34?

[Stu Fyfe]

There isn't any exposed area to put a belt.
http://farymann.com/15w-p.htm

[ 09-30-2004, 09:52 AM: Message edited by: Stu Fyfe ]

[Bob Adams]

Solar panel?

[Ex-Oceangoddess]

Just curious - what sort of boat, and what's her name?

[chergui]

I just put a 6HP Farymann 18W in my boat and launched again on the weekend. Just a beautiful little engine, I love it. I don't have any zincs currently, not even in the water because the shaft is too short. I plan on bonding the boat though this winter to make up for it. The engine is amazingly quiet for a single cylinder and there the rubber mounts soak up most of the vibration so that the wooden mount it is bolted to takes practically no vibration. Can't really answer your question but I plan on adding zincs as others have suggested here.

[Dan McCosh]

Re: "zincs". Aluminum itself is a sacrificial anode material, and to provide anodic protection a more active material than zinc should be used--since the aluminum itself is more active than zinc. Dunno what this is, but I think it is magnesium. The sacrificial protection logically would be inside the cooling passages, with an electrical connection to the block. A zinc on the outside of the hull would have no affect on an aluminum block. I suspect the aluminum lives simply because the loss of the large mass of the block is small to any nearby materials such as bronze or iron. I would look at something like a bronze discharge seacock, though. Actually, this is something the folks at Farryman or another aluminum-block manufacturer would know about. Many outdrives are also made of aluminum, and basically are dealing with the same galvanic problem.

[Gerry S.]

Ex-Oceangoddess asked about my boat (at least I think it was mine he was referring to). She is a cold-moulded, raised deck, Bermudan cutter by the name of "Jolitee". LOD 28.5 ft., B 10.5 ft., draft 4.5 ft., displ. about 13,000 lb. She is very commodious, and sails well. The design is by Robert B. Harris. Someday maybe I'll have a good picture of her under sail, and I'll be able to figure out how to post it.

Re. sacrificial anodes for aluminum, I've found that magnesium works best on immersed aluminum structures at my workplace, but from personal observation, zinc also has some ability to protect aluminum.

[Dave Fleming]

Hmmmm, I was under the impression that Copper and its alloys ie. Bronze were no-no's near Al.?

Somebody want to clarify that for me please?

[Dan McCosh]

The galvanic scale would imply that aluminum would be "lost" to nearby bronze when both are imersed in salt water. A sacrificial anode uses this to let the anode erode, thus saving the bronze. If you want the aluminum to stay intact, it shouldn't contact bronze.