flushing question

I think I once saw a post cautioning about pressurizing the water intake line during driveway engine testing. I think I have read through all of the recent posts on flushing, etc. I cannot use a fake-a-lake because of the location of a trailer bunk. The only other technique I saw that would not pressurize the water intake hose was the one about filling the bilge with water and then allowing the intake hose to draw water from there. If there is no problem with water pressure, the easiest way seems a T in the water intake line just downstream from the hull intake with a petcock between the T and the hull intake. Any advice would be appreciated.

I Use 79s technique. I tried using a hose to a large bucket and allowing the raw water pump to pull it but the flow was way faster than I could keep the bucket filled. Now I hook the hose up to the intake hose where it connects to the hull, then when I am ready I have my kids turn on the water just befor I crank the boat. My concern was not with pressure but with the wet exhaust filling with water and running back into the heads and pooling when the motor was off. Water pressure should not be an issue on any serviceable hoses or components on the engine.
Just my .2$
Dallas

My only problem with filling the bilge is that I KNOW I would go do something else while the bilge was filling and forget to come back to the boat....presto, a sunk boat on the trailer. Don't laugh, I did it twice to my old wooden Chris Craft!

I personally use a fake-a-lake ( I know, Waterlover can't) and turn the hose on and walk back to the boat and start it. Two things here: 1. If the impellar is in good shape, I figure not much water is getting past the rwp. The water that does get past is simply going to flow out of the exhaust. The exhaust manifold design would not let it flow back into the engine via the exhaust valves unless the exhaust hose is plugged or blocked.

FWIW, there are automatic flushing valves available for this purpose.

if your houshold pressure is low and it is not flowing water at the maximun rate for the size of the pipe it's flowing through then the RWP will change the rate at which the water flows. Now it will still be less than what the RWP can flow due to the difference in dia on the RWP 1.25 to say a .75 for your house.

ya I'm doing it right now, it's easy when you have dual monitors

Do NOT use that device, it will destroy your engine! Just to ensure you are not tempted, you should remove it and send it to me immediately







Just kidding, use it with no worries.

First time flusher here. Looking at my 1992 manual, on page 4.9 they diagram a "fresh water flushing" illustration. This instructional is for flushing your engine if the boat has been in salt water. Is this the same approach for running your engine out of water for cooling purposes? Also, it references a relieve valve which prevents excess pressure to the engine. Gotta love "newbies" eh?!

One thing I've noticed using the fake-a-lake, is you don't want the water pressure wide open while the boat is not running, the seal in the pump if worn can leak, maybe damage it. I don't think it was designed to hold back against that kind of pressure.

Well, not really other than one important difference (I believe). With a fake-a-lake, any excess water pressure will leak/escape from around the fake-a-lake. By connecting the garden hose directly to the RWP suction hose, you are introducing pressure to the pump which I suppose could damage the shaft seal (but really do not know). My thought is that otherwise it does not really matter as any water that gets pushed through the cooling system simply exits the exhaust pipes. Given the design of the exhaust manifolds and risers, it cannot enter the engine cylinders. With that said, I only have experience with exhaust systems with risers. Some of the older engines do not seam to have the risers, but Somehow, the theory must be the same or engine damage would surely be the result.