Do I need an Anti Siphon valve?

[Bold Rascal]

I didnt want to hijack a very recent thread on the subject so...

When I relocated my heat exhanger higher and closer to the engine, I also installed a new hot section on the exhaust to gain some additional available height and achieve the recommended 8" between the raw water connection and the (Vetus type 2) waterlock.

All my hoses now run downhill from the vertical heat exchanger to the raw and cooling water connections without any other high points. (MMI FWC)

My discharge end of the raw water connection back into the exhaust is at least 3-4 inches above the waterline. Do I need an AS valve?

I'll try getting some photo's this weekend.

Thanks
Mike

Ps: Nice looking Install Rick..

[Kurt]

Based on your description, your set-up sounds pretty standard. Even with that set-up, you should have an anti-siphon valve installed. These are VERY simple to install - I posted some pics of my custom installation something like a year or so ago. That being said, my boat spent its entire life until a couple of years ago without an anti-siphon valve with no apparent problems. As far as I see it, the anti-siphon valve is an added security measure that should be used on your engine (and your head too!).