Anti-syphon break

[Photo Chief]

I am currently refitting and repairing needy items on the Bristol 27 that I purchased in September. I came across the anti-syphon valve in the raw water circuit which is spitting water during engine operation. The metal cap seems to be broken inside causing the valve to leak a small amount of water while the engine is running. The motor is a BMW D12 diesel so there is no hope of securing original equipment. West Marine only has one overpriced cheap plastic replacement. I thought that the valve used on Yanmar single cylinder engines would probably work. Is the Yanmar valve metal? I need a 1/2" valve. Are the valves available from Yanmar or are they second party parts? What do Cape Dory owners think of the idea?

BTW. Who is the owner of the CD27 slipped at pier 7 at Cove Marina on Little Creek Amphibious Base? Named "Sea-renity".

[gkempin]

Rich,

I have a Vetus anti syphon valve installed on my D7. It is plastic but quite adequate for the job. It comes in two versions:
1. Air Vent V - this model has a pressure valve and is self contained but requires periodic maintenance to insure that salt doesn't build up and clog the valve.
2. Air Vent H - this model has a hose connection to the outside of the hull. There is a constant bleed of cooling water when the negine is running. It comes with a 12 foot hose (thin plastic as used with a windshield washer).

I recommend the latter since it is foolproof.

There is a copy of the Vetus spec sheet at http://groups.yahoo.com/group/bmwmarineengines/
in the photo folder.

You may have that type installed and missing the hose without realizing it - check it out.

Also check out Geoge Huxle's BMW site below for general D12 maintenance issues.

http://wavelength30.1l.com/BMWD7.htm

I do have my old anti-syphon valve that I replaced which I can send you if you insist on a metal valve.

Gunther

[Photo Chief]

Gunther,

Thanks for the info. I did some more research and found another source that stated the same info you gave me about running a small tube overboard. I like that idea and will use it. However, I did some quick mental calculations and determine I would need to do five circumnavigations to produce enough water from this valve to fill a one gallon bucket. That being said, why not run a shorter tube to the bilge so that the spit will not fall on the motor. Two feet of hose vs 10 to 15 ft?

BTW Gunther, "Catherine" is a beauty.

[gkempin]

Rich,

The important thing is to locate the hose so you can easily see it piddling water when the engine is running. When it stops you know you have a problem. The length of my hose from the valve is only 2 feet.

Gunther