I have a boat with 2 each 380hp 454s, a 7Kw Westerbeke genset, and air
conditioning. (no consumption jokes, please)

I run this in Fl. salt water. Because of the waterlift muffler systems
on the engines and the gen, I can't use the Mercruiser fresh flush
inlets on the engines. They need to be run, and fresh water must
replace salt water at the pump intakes. Same for the air conditioner
pump.

I'm thinking about rigging a water tank in the engine room that would
have hoses attached and then have them Y into the water pickups,
probably after the sea strainers, with a Y valve, or gate valves.

I would only run one engine at a time, and only long enough for it to
push fresh through the system. Outside of just trying it with a
bucket, or something, what's the easiest way to calculate the
anticipated water consumption for this engine at say, 900 RPM, and for
the Westerbeke? The A/C will be a sub set, for sure.

The tank could be refilled between engine flushes, but I'd rather get
one that could accomodate everything. Another angle would be to tap
into the ship's 70 gal fresh water tank, but that's across the vessel,
and the runs would be long.

(C. Sadler) wrote in message om...
I have a boat with 2 each 380hp 454s, a 7Kw Westerbeke genset, and air
conditioning. (no consumption jokes, please)

I run this in Fl. salt water. Because of the waterlift muffler systems
on the engines and the gen, I can't use the Mercruiser fresh flush
inlets on the engines. They need to be run, and fresh water must
replace salt water at the pump intakes. Same for the air conditioner
pump.

I'm thinking about rigging a water tank in the engine room that would
have hoses attached and then have them Y into the water pickups,
probably after the sea strainers, with a Y valve, or gate valves.

Maybe I am missing something here, but why not just hook a fresh water
hose in at this point instead of trying to feed it with a tank?
Scotty

Are you shure you cannot use the LATEST flush kit by Merc.?


"C. Sadler" a écrit dans le message de
m...
I have a boat with 2 each 380hp 454s, a 7Kw Westerbeke genset, and air
conditioning. (no consumption jokes, please)

I run this in Fl. salt water. Because of the waterlift muffler systems
on the engines and the gen, I can't use the Mercruiser fresh flush
inlets on the engines. They need to be run, and fresh water must
replace salt water at the pump intakes. Same for the air conditioner
pump.

I'm thinking about rigging a water tank in the engine room that would
have hoses attached and then have them Y into the water pickups,
probably after the sea strainers, with a Y valve, or gate valves.

I would only run one engine at a time, and only long enough for it to
push fresh through the system. Outside of just trying it with a
bucket, or something, what's the easiest way to calculate the
anticipated water consumption for this engine at say, 900 RPM, and for
the Westerbeke? The A/C will be a sub set, for sure.

The tank could be refilled between engine flushes, but I'd rather get
one that could accomodate everything. Another angle would be to tap
into the ship's 70 gal fresh water tank, but that's across the vessel,
and the runs would be long.

What you're missing is that I don't think a garden hose will feed a
454 on the inlet side of the water pump while running. Maybe I'm
wrong. Just not sure how to predict that. I can't just use the
manifold flush built in to the engines because these, and the genset
have Vernalift water lift muffler systems, which REQUIRE the engine to
be running in order to lift the water from the cannister. Using the
inlet without the engine running would flood the cylinders, and
running the engine without replacing the seawater pickup is obviously
not going to accomplish anything.

since I have 2 engines, a generator, and an air conditioner pump, why
not develop a system that could flush all of em with the least amount
of fuss?


Maybe I am missing something here, but why not just hook a fresh water
hose in at this point instead of trying to feed it with a tank?
Scotty

"jean" wrote in message . ..
Are you shure you cannot use the LATEST flush kit by Merc.?


"C. Sadler" a écrit dans le message de
m...
I have a boat with 2 each 380hp 454s, a 7Kw Westerbeke genset, and air
conditioning. (no consumption jokes, please)


From the Mercrusier installation/operation manual (these are 1998
engines)
WARNING: Do not use the flush fitting if you have a water lift muffler
system.

My assumption is that you must have the engine running to create a
lift with the exhaust. If you do not run the engine, as these fittings
were designed, you will fill the muffler, and water will back into the
engine. If I run the engine, I will simply be mixing more salt water
in with the fresh.

Are you aware of a kit specifically designed for water lifts? I'm
guessing that it would be replacing the water flow at the intake of
the raw water pump, either through strainer adapter fittings (hose
fittings on the sea strainer lids), or some other way of injecting
fresh water in place of salt.

I'm skeptical that a garden hose can flow 10 gallons a minute at 10psi
from a 5/8" hose to a 1.25" hose. (and that's at 900 RPM). Am I being
over cautious?

C. Sadler wrote:

From the Mercrusier installation/operation manual (these are 1998
engines)
WARNING: Do not use the flush fitting if you have a water lift muffler
system.

My assumption is that you must have the engine running to create a
lift with the exhaust. If you do not run the engine, as these fittings
were designed, you will fill the muffler, and water will back into the
engine. If I run the engine, I will simply be mixing more salt water
in with the fresh.

Are you aware of a kit specifically designed for water lifts? I'm
guessing that it would be replacing the water flow at the intake of
the raw water pump, either through strainer adapter fittings (hose
fittings on the sea strainer lids), or some other way of injecting
fresh water in place of salt.

I'm skeptical that a garden hose can flow 10 gallons a minute at 10psi
from a 5/8" hose to a 1.25" hose. (and that's at 900 RPM). Am I being
over cautious?

A 5/8" garden hose will deliver about 10 GPM at a pressure drop of 6 PSI
so with the engine pump pulling and the water system pushing you should
be pretty safe.

--
Glenn Ashmore

I'm building a 45' cutter in strip/composite. Watch my progress (or lack
there of) at: http://www.rutuonline.com
Shameless Commercial Division: http://www.spade-anchor-us.com

Glenn Ashmore wrote in message news:fpszb.77476 A 5/8" garden hose will deliver about 10 GPM at a pressure drop of 6 PSI
so with the engine pump pulling and the water system pushing you should
be pretty safe.

Now you're talking. That makes me less leary of the Perko inline flush
kits.
If only they weren't plastic with a spring......
Had a friend lose one of these between West End and West Palm as it
split in half, but that's another soggy story.

BTW,
My local MarineMax dealer is speaking of a "new" flush kit from
Mercruiser that is compatible with lift sets.

Time to talk to MC.