engine flushing...or closed cooling

[tn shenanigans]

Hi
My boat was a fresh water boat until 10 months ago and as I consitently read about the risers and manifolds failing I am ready to bite the bullet and and have manifolds and risers replaced

My question is considering the expense and reoccuring nature of replacing riders and manifolds is it beneficial or feasable to a conver the raw water system to a closed water cooling system....

If not is there any value to a neutra salt or super flush system

Does any one have experience with either and if so what are the expenses associated

thanks

Scott

 

[BahamasBlair]

Search the site for engine flushing. There are some big threads with photos and how tos. I just changed all 4 exhaust manifolds due to their failure. I am modifing the intake hoses to allow the installation of a T and a water valve to allow me to attach a fresh water garden hose to flush the engines after every cruise. The T will be located right beside the raw water filters. All you have to do is attach the garden hose, close the seacoks and run the engine on idle for two or three minutes. Leave the seacoks closed until your next cruise. With this rig, your exhaust manifolds, Kool fuel system and heat exchanger sit with fresh water rather than salt water. Down here in the Bahamas, our ocean water is almost 90 deg F . Combine salt with that and you have a very nasty mixture.
This isn't my idea, I found it on the site. I think if you search for Hampton, he may have written it.
I can send you a photo after I get it installed.

 

[trit21]

The problem I ran in to when changing from raw water to fresh water are as follows:
1) even though you have a heat exchanger, the exhaust manifolds from Mercury are still raw water cooled, the only thing fresh water is the block. From what I have seen, most failures are the manifolds

AND

2) I was told when you change from raw water to fresh water (heat exchanger system) you also have to change the ECM, a very expensive part.

Obviously your system may differ from mine but just wanted to tell you what I was up against when I tried the exact same thing.

 

[BahamasBlair]

Here is the thread that explains exactly what you need to do.
http://clubsearay.com/forum/showthread.php?t=8878&highlight=engine+flushing

I'm doing it on my 340DA next Saturday. Just don't have the parts yet.

 

[fwebster]

Scott,

There is 1 other factors to consider here..........

Most risers fail because of corrosion but it isn't where you might think. Even boats with freshwater cooling require replacement of the risers. The manifolds seldom fail on their own, but usually due to water dripping into them from the riser that has failed above it or because of a bad riser to manifold gasket. The reason that FWC won't eliminate the risers is because most of them rust from the exhaust passage into the cooling jacket not the other way around. This is because the exhaust port is open to salt air 24/7/365. Moist humid salty air is in the exhaust system all the way up to the valves in the heads and even into the cylinder if the exhaust valves are open.

Freshwater cooling will, however, stop the accumulation of rust sediment in the engine block skirts and that is going to about double the life of your engines. Although, most 7.4's die a needless early death when they get full of sea water because someone neglected to check their risers regularly.

A flushing system is going to help but will not remove the exposure the engines have to salt water, and every time you run the boat, you accumulate some rust sediment. With flushing, the engines are left with freshwater in the blocks so you form less rust, but you don't eliminate it.

 

[tn shenanigans]

grat info... thanks

 

[mark guthrie]

I just purchased a 280 with 4.3s and alpha drives. I am looking at superflush. what did you decide? do you have bravos?

thanks,

Mark
St. PETE, FL

 

[mark guthrie]

Anyone have input specifically for the Alpha drives? I am buying a 280 and need to install a flush kit. I'm looking at superflush? Any comments?

 

[Bucit]

Anyone have input specifically for the Alpha drives? I am buying a 280 and need to install a flush kit. I'm looking at superflush? Any comments?

From what I have read and been told you cannot put a flush system on the Alpha outdrives. The impeller is in the leg and needs to have water run over(through) it or you will burn it up. The Bravo's have thier water pump in the ER and thus can get away with a flush system. Trust me, my 280da is lift kept and it's a pain in the ass using the muffs. BTW, where are you located in St. Pete?

 

[SteveRuss]

Superflush can be used with any engine/drive set-up except those with special mufflers. I installed it on my 215EC with a 5.0 Alpha Gen 2 and have installed two on my current boat's 5.7 EFI B1s. This is the easiest flushing system to use because it is done with the boat not running, in or out of the water with a simple garden hose hook-up. The principal is simple water fills up the block and exhaust system on both sides of the T-stat by running hoses with fittings to the block and manifolds using the drain plug ports. (replace drain plugs with special fittings and hose barbs). The superflush bullit pulses water through the system to dislodge salt and scale while flusshing. The original system was $199 about 5 years ago and had brass fittings and quality ss hose clamps. The system is now $299 and everything is plastic and cheap. I had to change out all of the plastic fittings with brass ones after an exhaustive search and changed all of the hose clamps to top quality ones. Still works great but not worth $300. Customer service at superflush is non-existant. There are benefits beyond flushing though, winterization is a breeze with this system. I pull the lower hoses to flush the bulk of the water and then replace then pump anti-freeze into the superflush port with a hand RV water system pump until it comes out the exhaust. Takes about 5 minutes per engine with the motor not running.

 

[saopm]

Anyone have input specifically for the Alpha drives? I am buying a 280 and need to install a flush kit. I'm looking at superflush? Any comments?

I haven't done it yet, but I think I figured out a way to add a flush kit to my Alpha 4.3s. My engines have the single point drain system so I was going to cut the two drain hoses that go to the bottom of the engine block. I will cap the ends that go into the drain manifold and plumb the hose that go to the block to a fresh water tap. I will not be able to run the engines while flushing, but it should flush everything out just fine and exit the exhaust. My old Four Winns had this setup and it work well. I can't see why it would work on the Alpha setup.

 

[Fonkster]

Steve where did you end up finding the brass brass Male to female fittings to replace the plastic ones that broke on your super flush system?

Superflush can be used with any engine/drive set-up except those with special mufflers. I installed it on my 215EC with a 5.0 Alpha Gen 2 and have installed two on my current boat's 5.7 EFI B1s. This is the easiest flushing system to use because it is done with the boat not running, in or out of the water with a simple garden hose hook-up. The principal is simple water fills up the block and exhaust system on both sides of the T-stat by running hoses with fittings to the block and manifolds using the drain plug ports. (replace drain plugs with special fittings and hose barbs). The superflush bullit pulses water through the system to dislodge salt and scale while flusshing. The original system was $199 about 5 years ago and had brass fittings and quality ss hose clamps. The system is now $299 and everything is plastic and cheap. I had to change out all of the plastic fittings with brass ones after an exhaustive search and changed all of the hose clamps to top quality ones. Still works great but not worth $300. Customer service at superflush is non-existant. There are benefits beyond flushing though, winterization is a breeze with this system. I pull the lower hoses to flush the bulk of the water and then replace then pump anti-freeze into the superflush port with a hand RV water system pump until it comes out the exhaust. Takes about 5 minutes per engine with the motor not running.