Engine flushing while tied to a wet slip

[crawdadric]

1985 Sea Ray SRV300 with twin 5.7L Mercruisers and alpha I outdrives. Sea water cooling without an engine mounted sea water pump (water pump in Outdrive).

This might be a little long, please bare with me. Currently my boat is dry stored and this spring I will be keeping her at a marina in a wet slip.

I'm looking into an engine flush system that uses three ball valves. The valves use a "T" connector and installed inline with the hose from the Outdrive supply to the engine thermostat housing. One valve cuts off the Outdrive supply, the other cuts off supply to the engine and the third valve allows supply from a garden hose.

When flushing (engine running) you connect the garden hose and open its valve then close the valve coming from the Outdrive. This will flush the engine with tap water. Then you shut down the engine and close the engine supply valve and open the Outdrive supply valve to back flush the Outdrive.

My question is - when you run the engine and cut off the Outdrive supply valve, will this cause the water pump in the Outdrive to fail because of pressure build up?

 

[Haut Medoc]

Re: Engine flushing while tied to a wet slip

I don't know for sure, but I would think that pressure needs to go somewhere.....
The cheap way would be to make up a "T" between two muffs & put them straight on the drives, IMHO......

 

[zzzzz]

Re: Engine flushing while tied to a wet slip

actually,you don't need to go through all the plumbing...we install a Perko brand mechanism that is similar to a ping pong ball between 2 springs-the ball blocks off the water from the drive(prox 4 to 6 lbs pressure)with the force of the garden hose water(prox 10 to 12 lbs pressure)and thus provides your freshwater flush while still in the water...for 1" hose(from drive) it is Perko #0456DP6 and for 1 1/4" hose it is Perko #0456DP7..prox $90...we've installed many of these for our customers that keep their boats on a lift8)

 

[crazy charlie]

Re: Engine flushing while tied to a wet slip

I reach down into the water to my drives with muffs.As long as the drives are up all the way it is not too tough to do,

 

[crawdadric]

Re: Engine flushing while tied to a wet slip

zzzzz - I was looking at the Perko also. My concern was the supply loop from the outdrive. Because you are not using muffs, that part of the drive does not get flushed with the salt away. The Perko design also cuts off the outdrive like the manual ball valve, so I guess the impeller would survive turning against pressure. The Perko is about half the price of the ball valve assembly, so I might go with that.

Haut Medoc and crazy charlie - On my trailer boat, I do the muffs every time, no problem. But on this Sea Ray, which will be at the slip, I was looking into flushing in the engine compartment because it would be easier for me then to reach over the swim platform. I know one day I would fall in and the video would end up on the internet or America's Funniest Videos - LOL.

 

[Fishermark]

Re: Engine flushing while tied to a wet slip

Not to argue the point, because I really don't know the answer, but it seems to me that it would be bad to simply block the flow from the impeller in the lower unit. Out of curiosity I looked at that perko unit online, and note that it is for inboards. It talks about blockinng off the flow of water from a hull fitting - not from a "pumped flow" from an I/O. It would work with a Bravo, but I doubt it would work with an Alpha 1.

But then again.... I've been wrong before! d

 

[zzzzz]

Re: Engine flushing while tied to a wet slip

Hey Mark ! it most definetly works with an Alpha...stop by Gulf Coast(EL JO) and I'll show ya'...PS-now we're tied on number of posts !8)

 

[Fishermark]

Re: Engine flushing while tied to a wet slip

I didn't notice the number of posts... I guess this makes me one up!

Back to the subject at hand... I wonder if it truly blocks the water from an Alpha, or if it mixes it?

 

[zzzzz]

Re: Engine flushing while tied to a wet slip

my guess would be that it blocks it due to having twice the pressure8)

 

[Fishermark]

Re: Engine flushing while tied to a wet slip

Okay. You win!

I also suspect you are just trying to up your post count.
8)8)