Volvo Penta Cooling system-gctid804650

[alanmoor]

I was reading up on the cooling system for my Volvo Penta 5.7 and DuoProp. I was always under the assumption that there is an impeller in the outdrive, but the Clymer's manual makes no mention of this - only the impeller mounted to the front of the harmonic balancer and the engine water pump.

The instructions for layup say to disconnect the source hose just inside the engine compartment and put a water hose in it and secure it, turn the water on (no mention of pressure) and then start the engine to clean it out I guess, then take the hose out and put it in an oil/water mix and let it suck it out.

The section on flushing says to use the muffs on the outdrive and warns not to use full pressure.

The instructions for layup seem to be the "safe" way to make sure enough water is getting to the engine. However, that would bypass the outdrive all together and burn up an impeller if there is one in there (that I can't find any reference to in the manual, whether it be the cooling section, or the outdrive/lower unit section).

I've used muffs in the past, but usually just to make sure the engine will start before going to the lake. It always made me nervous because I'm never convinced the engine is getting enough water (not because of any evidence, just because of paranoia).

So:

[ul]

[li]On the Volvo Penta DuoProp, is there an impeller in the outdrive?[/li]

[li]If not, is there any reason not to connect the garden hose inside the engine compartment rather than the hassle?[/li]

[li]What difference does it make if you turn the water all the way on or not? Eventually the pressure will be the same or, if not turned on far enough, the engine will be starved for water[/li]

[/ul]

[Pcpete]

Up front, I haven't had a Volvo in a long time. However, I did find a site that has the schematics for all of the Volvo models here. http://www.marinepartsexpress.com/VP...RANSMISSION%2F

What I do know, assuming I'm correct from looking at a random dp schematic, there is no water pump in the drive.

You could install a water hose connection, and there are kits available made for freshwater flushing motors. However I'm not sure if it's something that's made for use while the engine is running.

As to the reason to turn the water all the way on, IMO, it's boilerplate to cover any water systems in the worlds pressure and volume. My house has over 95 psi and a 1" line feeding it. At the same time my friend is on a well with about 40 psi and a 3/4" line. If I was making a general recommendation as opposed to a pressure/volume grid that someone is bound to misread and blame me.