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flushing out the salt water

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gunkholer

Member
I have 454 crusader engines and I've just spent a fortune getting all the crap out of my salt water side of my engine cooling systems (heat exchangers, trans cooler, exhaust elbows) on both engines, that were completely clogged up. So I'm thinking I'll flush out the system each time I return from an outing from now on.
My plan is to put a T into the raw water line going to the trans cooler ( the first component) from the salt water pick up line coming in from the intake on the bottom of the hull. I'll put a ball valve in that raw water hose just before the trans cooler . On the other part of the T fitting, I'll put another ball valve. That ball valve will have fresh water coming in from a new hose I'll install from a fitting on the side of my boat that a garden hose can screw into. From that fitting I'll hook up a garden hose to the freshwater supply on the dock.
When I get back from an outing, I'll hook up a garden hose from the dock freshwater supply to the inlet on my boat that will lead directly to that ball valve I just mentioned. Then I'll shut off the salt water ball valve, turn on the tap on the dock fresh water supply and then open the fresh water valve. Then run the engines for 15 to 30 minutes. That should be enough time for all the salt water to be pushed out of the trans cooler and exhaust elbows and the heat exchanger and it will leave fresh water in all those parts once I turn off the engines, until the next time I head out. Obviously it would be essential to remember to reverse the ball valves direction on both engines before I head out again.
Does all that make sense or am I overlooking anything?
 
missnancy said:
That should work though you don't want to run it up in the rpms because the hose wont keep up.
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I agree missnancy. I've given that some thought because the hose I use for washing down the boat is one of those types that shrivel up to about a third of their length when not under pressure. Those types of garden hoses are known for not producing as much pressure. So I think I would get a hose dedicated to just this purpose. Preferably one inch in diameter and as short as possible. I've read that the 454 crusaders like to idle at about 1500 rpm. Perhaps 30 minutes is more time than necessary. Maybe closer to 10 minutes might be enough. During the winter months, in the past I've generally fires up the engines every 30 days for 30 minutes when the boat is not in use. However this might not be a good idea for that short of a time frame ( 10-15 min) on cold engines.

There is a brass fitting that comes off the bottom of one of the 8" riser on each engine. A small hose leads down to the stuffing box from that fitting. That fitting has a drain plug. I'm thinking I could unscrew that plug ( it's above the water line) and take a sample of the water in the elbow after each time. Shortening the time frame each time, until I sense a salt water taste. I'm thinking that should give me a good sense of time required to get rid of all the salt water.
 
Thanks RicardoMarine for suggestingthat option. I googled the product and found a pdf instruction sheetthat would come with the product.
https://www.perko.com/images/catalog/pdf/flushpro.pdf
They mention that a you still need toinstall a seacock before the unit to insure the raw water is shut offprior to using it if the boat is in the water. Also it seems thatone would have to unscrew the fresh water intake and recap it eachtime. Otherwise raw water would flow back along that fresh waterintake. No big deal though because the water hook up on the side ofmy boat has an o-ring seal cap for it anyways. But if I have to getin the engine room to shut off a raw water intake anyways, my methodis only a matter of turning one more ball valve and saving theexpense of 2 of those units. The internal automatic valve thatactivated under pressure would be a real concern if it shouldmalfunction while under way and close off the flow of raw water.
They also mention not to exceed theengine past 1100 rpm. So I'm guessing that if the rpm is greater, theaverage fresh water pressure from a garden hose won't keep up.
Also it did mention that 5 to 10minutes was enough time to flush out the salt water, so that's goodinfo to know.
 
Opps sorry for what looks like a ton of spelling mistakes. This forum obviously doesn't like copy and paste. I created my post in open office to insure I didn't have spelling mistakes but it backfired. I should have double checked before posting. Sorry.
 
I use 1 inch nylon reinforced hose...I only run the engines about five minutes when on the hard (engines are fresh water cooled but prior to launch in the Spring I want to know all is well in the engine room)

ScreenShot001.jpg
 
I USE SALT A WAY at winter lay up time and several times during the season. Plain fresh water the other times. Got 11 seasons out of a pair of OEM MERC dryjoint elbows and they were still VERY usable when I took them off.

Re: a garden hose to your hose bib. I'm not a fan of pressurizing the input to a raw water pump for a number of reasons.

1) "Timing"... I would not want water running into the inlet of the pump when the engine isn't running, nor would I want no water when the engine is running.

2) The raw water pump "meters" the water per the engine demands, that said, I have a short (3 ft) length of hose ( same type you use so I can see whats going on) that connects to the flusher inlet with the other end stuck in a 3 to 5 gal bucket on the deck. I let a garden hose free run into the bucket.
a) This lets you check to see that the raw water pump actually sucks water,
b) Prevents pressurizing the raw water inlet and...
c) Gives you a means to run anti freeze into your system easily in the fall. My MERC 5.7L 260 HP with mufflers mounted inside the transom, takes about 2.5 gal of antifreeze before it flows freely out the exhaust ports. It also allows easy use of Salt a way. I use 2 oz per 4 gallons water. I run until the pail is ALMOST dry and let it sit for 20 mins.

Importance of flushing... My boat's previous owner flushed the original RAW water cooled engine every time he used it. I have no idea as to the age of the manifolds or elbows, but after 37 seasons in salt water, the block was still OK.
 
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All good food for thought sandkicker. However I've had the raw water pump apart when I changed the impeller. It's pretty basic and I don't see how pressure from a garden hose could damage it if it was standing still so to say, for a period of maybe 2 minutes, given time to get to the start button at the helm. It's just an impeller in a confined space driven by a shaft connected to the pulley which is driven by the belt. Are your concerns about the water pressure breaking the seal and seat (sierra 18-3168) around the pulley shaft. I think the bearing also has a built in seal as well, but I can't remember for sure.
 
The way I understand it if you run water under pressure thru the raw water side of the engine with the engine off the water will circulate and fill the elbows with water and it will then flow into the engine thru the exhaust valves resulting in hydro lock and water in the cylinders. If the engine is running the exhaust gases force the water out of the elbows preventing this from happening.
 
hottoddie said:
The way I understand it if you run water under pressure thru the raw water side of the engine with the engine off the water will circulate and fill the elbows with water and it will then flow into the engine thru the exhaust valves resulting in hydro lock and water in the cylinders. If the engine is running the exhaust gases force the water out of the elbows preventing this from happening.
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I don't know about "...water and it WILL then flow..." I'd say "....water and it COULD flow into the engine..."
To me , an unacceptable risk.
 
Regarding the use of Salt-Away to flush the system, the company recommends leaving a quantity of the solution in the engine and not flushing it out. It is supposed to protect the metal with a fine coating of whatever is in it. There is a procedure on their web site but it very hard to locate. I load the liquid into the little bottle and turn on the valve to the fresh water position. Then start the engine and run it as long as you prefer, Then switch the valve to the Salt-Away position and cut off the engine and turn off the water about 30 seconds later. There will still be some of the solution in the bottle, which you can use to rinse off the drive and other metal areas.

As for whether the hose attachment can cause water ingestion into the engine, Mercruiser did modify their procedure to raise the engine RPM while operating on the hose so as to minimize that possibility. I think it was raised to 1100 RPM.
 
I am having my elbows and risers changed on my fresh water 454 crusaders this winter, this is what I am adding to the strainers to do a fresh water flush after I run them

https://www.groco.net/ssc-1250

From what I have been hearing its when the salt water sits in the hot engine is the problem.
 
I had a Crusader mechanic winterize my boat the first year so I could watch him do it. When he attached his sea strainer cap with the hose fitting, it told me you have to watch how much pressure you have coming through your garden hose. At idle the water coming through the hose with pressure is more than the engine needs and this causes water to get pushed back into the engine. He recommended the bucket approach mentioned above or a flush kit so the water is not pressurized and the engine draws only what it needs. I made my own flush kit with a sea strainer cap with hose fitting, a 12 gallon plastic drum (Hard to find), and some clear hose. I can run 12 gallons of salt away treated water through and then the 6 gallons of anti freeze for each motor. Works great.
 
matta0413 said:
I had a Crusader mechanic winterize my boat the first year so I could watch him do it. When he attached his sea strainer cap with the hose fitting, it told me you have to watch how much pressure you have coming through your garden hose. At idle the water coming through the hose with pressure is more than the engine needs and this causes water to get pushed back into the engine. He recommended the bucket approach mentioned above or a flush kit so the water is not pressurized and the engine draws only what it needs. I made my own flush kit with a sea strainer cap with hose fitting, a 12 gallon plastic drum (Hard to find), and some clear hose. I can run 12 gallons of salt away treated water through and then the 6 gallons of anti freeze for each motor. Works great.
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Very interesting matta0413. Did you find that 12 gallons was the right amount? How long did it take to use up that 12 gallons? Just in theory I'm thinking if it was determined how long it took to use up the 12 gallons. Then experiment filling the drum with fresh water supply from the garden hose with the tap half open or a third open or whatever, so it would fill the drum in the same amount of time. Would that not accomplish the same results?

On my 37 Trojan the sea strainers and the seacock on the hull bottom are very difficult to get at unless you lift the floor. Almost impossible to squeeze between the back of the engines and the genset feet first and backwards in a lowering motion and then avoid all the hoses and cables to get your feet on the hull bottom and then twist your body in a manner to be able to reach the seacock handle. Maybe if i was 5 foot tall and in my early 20's it might not be an issue. lol
My method would allow me to turn my ball valve at the front of the engines where there is much more room, but this would omit the sea strainers. Which I don't see as being necessary to be flushed out.

If using the garden hose from the fresh water supply on the dock with the tap open whatever amount less than full, is still too much pressure. I think I could build a custom aluminium fresh water holding tank and mount it just above the exhaust muffler or bellows or whatever that fibreglass box is called that the exhaust goes into from the 4" rubber exhaust hose, just before it exits through those 7 holes at the waterline into the ocean. My point being the marina wouldn't allow me to keep a 12 gallon drum on the dock and it would be too big to stow on the boat anywhere and a bit of an ordeal setting the whole thing up each time.
 
12 gal tank? stick hose from water pump inlet in to a 3 gal pail and let fresh water hose w/saltaway adapter run free into it for the recommended 30 seconds (after you first see salt away come out of the exhaust...its obvious) . To winterize, if you REALLY need to put 6 gal per engine into the system, just keep refilling the 3 gal pail ( don't let it run dry) until you get 6 gal in???
 
Sandkicker, you are correct. I used to do it with a 5 gallon pail but with my boat the cockpit lifts up to get access to the engines so I was constantly climbing up and down and it was a real PIA. So I now use the drum. It gives me a lot more time and can do everything with only having to climb over once. i am the type of person that does things by myself because I hate depending on other people. Help is always welcome but I don't want to have to wait for them.

Gunkholer, I have not timed it yet. I have only used the drum once as I have just replaced the 5 gallon pail system I used to use. But your point is accurate. When I used the 5 gallon pail that is exactly what I would do, adjust the water pressure to the point where the 5 gallon pail would not loose or gain water.
 
I think I'll experiment with the 5 gal bucket until I have a bench mark as to how fast one engine uses up the water. Then like you matta0413, I'll figure out just how much pressure to use from the tap to just keep the level constant. But I like the concept of a reservoir so to say and I think I'll build that holding tank above the exhaust muffler. Just by eye I think I can get a cylinder maybe 10 inches in diameter by 5 or 6 feet long, mounted on it's side. I'll bet somewhere on line there is a table that would tell me how many gallons that is, but I think it's going to be enough to do both engines. Plus I'll add water slowly from the tap and top it off at the end of each running of the engines.
Like you matta0413, I'm very independent, plus I like things to be convenient and professional looking. I already have the hose fitting adapter mounted right on the side of the superstructure so it all makes sense. The only issue I have is since the fitting is such that I screw the male fitting on the hose into it, the same as if you were joining two hoses together, then I'm going to have to add a vent to the tank to allow air to escape. I'm also going to have to figure out some sort of way to know when the tank is full. It shouldn't be too difficult with a couple right angle fittings off the one end. One above the other with a clear hose connecting them.
 
GaryDouglas said:
To reduce the tap water pressure to your engine, how about using a regulator like this one?

https://www.amazon.com/Renator-M11-...1N7JZTYX/ref=cm_cr_arp_d_product_sims?ie=UTF8
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ummmm, I'm not sure if that would be of any advantage to me GaryDouglas. Once I know what amount of flow of water through the garden hose is necessary or required, then it's just a matter of remembering if I have the tap cranked open a half turn or full turn or whatever it needs to be. Although since I can never remember where I put my keys these days I'll probably forget the tap position too, so maybe one of those regulators would be a good idea after all. Now all I have to do is remember what we're talking about here. haha
 
gunkholer said:
ummmm, I'm not sure if that would be of any advantage to me GaryDouglas. Once I know what amount of flow of water through the garden hose is necessary or required, then it's just a matter of remembering if I have the tap cranked open a half turn or full turn or whatever it needs to be. Although since I can never remember where I put my keys these days I'll probably forget the tap position too, so maybe one of those regulators would be a good idea after all. Now all I have to do is remember what we're talking about here. haha
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The advantage of using this device is that you can take it anywhere and get the same reduced pressure, since it is already adjusted to your pressure setting.
 
I've been flushing my FWC 454's since I bought my boat nine years ago. I installed the Groco SSC's inline with the seacocks. After I'm done for the weekend, I connect dockside water and run the engine for about 4-5 mins. I came up with that time because it takes a little less than that for me to run about 6 gals of pink when winterizing so I know that's the full capacity.

In terms of pressure, I keep the shutoff valve at around 3/4 open. I also tapped off my FW plumbing and added a spicket right in the engine room so that I can flush w/o connecting to the dock. I do that on the occassions when maybe I'm flushing but not washing the boat or maybe somewhere where it's not convienent.

Real world results..... My 5 year old risers/elbows looked almost new, at least from what I could see (always a risk and unknown) so I changed them anyway. I will definitely go longer this time around. I always flush at the end of every weekend but will sometimes skip it if going out consecutive days. When we travel, I always flush if staying for more than one night. So, probably give myself a 90% rating.
 
This is what we ended up adding when the risers and elbows were done. I like the idea of suction from a pail (same way i winterize) that way no worries about pressure, also I could just add some salt-away to the pail. I do have a fresh water source in the engine room so this should work out good...

flush valve.jpg
 
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Brownie289 said:
This is what we ended up adding when the risers and elbows were done. I like the idea of suction from a pail (same way i winterize) that way no worries about pressure, also I could just add some salt-away to the pail. I do have a fresh water source in the engine room so this should work out good...

View attachment 19730
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So in the picture the hose on the bottom looks like it is picking up raw water. The hose on the top looks like it's going to the raw water pump. If that's the case, I'm curious what boat is this in? My raw water pick up is aft of the engines right against the aft engine room wall and it's literally impossible to get to the on/off valve on the saecock without removing the salon floor. I thought about repositioning the seacocks and sea strainers just forward of the engine, just like in your picture but I was advised by several people on a Trojan forum that Trojan probably put them aft of the engine for raw water flow reasons and perhaps if I moved them fwd of the engine I might create turbulence or disruption of water flow and perhaps draw air at certains RMP. I have a 37 Trojan. If you think about it, it's so obviously advantageous to have them easily accessible fwd of the engines, just like in your picture. So one can only think that Trojan put the raw water pickup aft of the engines for a specific reason. ???
 
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