naive, that is absolutely no such force in nature called "suck", therefore the
exhaust gases can not such the water around the elbow.

have you any idea at all how a siphon works??

obviously not.

think about it, naive, just what in hell _pushes_ the water "around the elbow"?
When the engine is running the exhaust gases do, when the engine is not
running, what?

It's pretty obvious from that diagram that when the gasses in the
exhaust cool they will suck in water 'round the exhaiust loop which will
then try to fill the engine... without a siphon break... as I said.

Cheers


Jeff Morris wrote:

"JAXAshby" wrote in message
...

jefffies, you are spouting your ill-informed opinion.

having the water injection point anywhere near the waterline is forbidden
(not
to mention stupid) unless there is no other way possible.


No, you're wrong as usual. It is a definately forbidden to have the
injection
point near the waterline with the appropriate protection, such as a siphon
break. I even posted the ABYC guideline.

Given the geometry of the most commonly used engine (and most others), and
taking into account heel angle and an extra margin for overloading, there's
less
than a foot between the injection and prop shaft. Since one wants to
minimize
the down angle (15 degrees is the max, but under 8 degrees is better),
you'd
have to put the engine in the bow to ensure the injection point is always
above
the waterline.

Here's a diagram of the boat in question, a Pearson 30. Its pretty clear
to see
that even with an extreme angle, the engine is completely below the
waterline.
A siphon break is obviously required.
http://pearsoninfo.net/30/30.htm





This is total nonsense. It is quite common, even likely, that the
injection
point will be at or near the waterline. Even if its nominally above, one
must
add the result of heeling, and possible overloading.

The distance between the injection (with the elbow that raises the
injection
up)
on the new Yanmar YM series is 16 inches above the prop shaft. While this
may
work out on a newer small, fin keel boat, this will very likely be well
below
the waterline on a more tradition full keel design where the engine sits
deeper.
And, if you subtract some for heeling and overloading, its actually hard
to
imagine a setup (other than very small boat) where the injection point
isn't
potentially at the waterline.

BTW, my boat, and my previous boat, has a siphon break. I was on a 43
foot
cruising boat today with a Perkins 4-108 where we determined the injection
point
was just about at the waterline.

Once again, jax proves he knows about as much about boats as the Tidy Bowl
Man.



"JAXAshby" wrote in message
...

oxxy, it is forbidden to have the water injection point below the

waterline,

except the rare case when it must be. But that rare case was not the
boat
under discussion.


"Jeff Morris"
scribbled thusly:


You can backpedal and nitpick that the water injection line is not part

of

the

direct path of the exhaust gases, but its pretty clear that everyone

considers

it part of the exhaust system.




You're learning Jeff.
This is where Jocks will claim victory.
He'll be wrong as usual calling it the raw water system or some such
other but hey. that's Jocks.


Oz1...of the 3 twins.

I welcome you to crackerbox palace,We've been expecting you.