jeffies, that line drawing from an advertising brochure does NOT show any
anti-siphon valve at all. Duh.

btw, it also doesn't show the water injection system, which *is*above the water
line.

jeffies? why oh why do you have such a hard time understanding just what makes
a siphon viable or not?

the P30, it is clear the engine is completely below the
waterline,

no it is not.

That's odd, two diagrams of the P30 have been posted which show the engine
completely under the waterline, with the possible exception of the forward
corner. The exhaust manifold is completely under, and if the boat heels or a
large crew is in the cockpit, it will be several inches lower.


and this is a typical situation.

plainly, you have not actually looked at a P30 engine installation.

It would seem you never have. Your word isn't worth diddlysquat, compared to
the actual posted specs.



plainly, you do not understand the issues involved *IF* one is stupid
enough
to
put the complete water injection system below the waterline. NOT DONE,
jeffies, and if you can not see why just shut up so you don't look so
stupid.

It is extremely common, actually the norm for traditional designs (where the
engine sits pretty low) and larger boats. Just go to a boat yard and tell us
how many propellers are close to the waterline.


NOT DONE.

Funny, I was on a 41 foot center cockpit boat today and I checked out the
engine
room. The entire engine was at least 4 to 6 inches below the waterline. It
was
hard to see how a boat of this general design could have the injection above
the
waterline. It was a proper installation, with a siphon break and a high loop
in
the exhaust line. Remember, the ABYC standards require a siphon break if the
exhaust manifold is below the waterline, so even the unusual setup of having
the
elbow and injection well above the engine requires the siphon break.

Jax, installing the engine below the waterline is done all the time, probably
on
a majority of the larger boats. The Practical Sailor article says, "Most
sailboat engines are installed below the boat’s waterline. This means that
special precautions must be taken to prevent seawater from siphoning back
into
the engine, with potentially disastrous results."


btw, jeffies, have you ever even seen -- let alone read -- the instructions
for
installation of a water injection system? You have?

OK, I happen to have the Yanmar 20GM20F Installation manual; I have two of
these
engines, both of which were installed with siphon breaks. The book says:
"When
the water outlet of the engine is below the waterline: In this case attach a
vacuum valve to the elbow of the cooling water pipe." It then has a picture
showing a loop with a siphon break 300 mm above the waterline, and a loop in
the
exhaust, 350 mm above the waterline. There was not a single comment
indicating
this was an inferior installation.

What word didn't you understand?

Sound pretty clear to me, what part of it do you not understand?

I've shown the ABYC standards, the engine installation instructions, the
comments of recognized experts. None of them even hint that there is any
truth
to your claims. All you've done is to keep repeating your flawed advice. It
doesn't matter how often you repeat it, its still wrong.


no, jeffies, stop once and for all telling us you have an associates degree
in
liberal arts physics from some technical college. If you did, no way in
hell
would you post what you post. This is easy stuff, jeffies. easy stuff.


You soiled yourself pretty badly with this one jaxie; better go home to
mommie
and change your pants.