2 waterpumps

[vxtech]

trying to understand purpose of 2 waterpumps on inline 6 with i think R drive 1977 vintage does out drive waterpump feed engine pump and assist in cooling or does out drive pump serve different area-like just manifold, and do both waterpumps work separately in fresh water cooled ,engine- antifreeze, outdrive- sea water ,and are that any diagrams to illustrate such systems, -just trying to learn more of whats goin on back there
thanks to all chris

 

[Don S]

Re: 2 waterpumps

The pump in the outdrive is a pressure type pump and forces water into the engine and manifold/riser for cooling. The engine pump is known as a circulation pump and only circulates the water inside the block. It takes both to make the system work. The circulation pump does not create any pressure at all, so it couldn't suck water up to the engine from the drive or force it out the back thru the exhaust system.

 

[Bondo]

Re: 2 waterpumps

Ayuh,...

Basically,...
The Impeller Pump, in the outdrive in your case supplies the water to the cooling system...
The motor's Circulating water pump just circulates the water Inside the block, when the T-Stat is closed....
The Pictures are in Here,...

 

[vxtech]

Re: 2 waterpumps

thanks fellas for the great explanation , it is very clear what each one does and is for. thanks again chris