Reverse rotation engine fresh water pump connections reversed?

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boattown
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Reverse rotation engine fresh water pump connections reversed?

Post by boattown »

I am rebuilding a pair Chrysler 318s and I did not take notice of the plumbing of the fresh water cooling system when I was disassembling the motors. Now that I am replacing all of the hoses, do I have to switch the inlet and outlet on the reverse rotation motor?

Both motors have non-directional pumps.
Joe
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Re: Reverse rotation engine fresh water pump connections reversed?

Post by Joe »

Hello, First the hoses are the same. The pumps are the same. One pump body will be 180 of the other. Look and see if the pump body doesn't show the direction of flow. Them figure out which way the belt is turning. I hope this make sense. The hose on the bottom is intake, the hoes on top is out put. Joe
1988 sedan flybridge. Black / White. 318 240 hp Aluminum aft deck hard top. Louisville Ky . Tartans landing. " KNOCKEFELLERS"
boattown
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Re: Reverse rotation engine fresh water pump connections reversed?

Post by boattown »

I am not sure that is the case here. Here are photos of both the port and starboard engines I took before I disassembled everything and the orientation of the pumps are the same. Any ideas?
Attachments
port 4.jpeg
port 4.jpeg (36.42 KiB) Viewed 10882 times
stb 4.jpeg
stb 4.jpeg (37.77 KiB) Viewed 10882 times
Fastjeff
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Re: Reverse rotation engine fresh water pump connections reversed?

Post by Fastjeff »

I'm gonna try to upload my sketch of which way everything goes. This site has tight restrictions on file size, so it might not work.

Here goes...

Jeff
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Impeller Orientation.JPG
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boattown
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Re: Reverse rotation engine fresh water pump connections reversed?

Post by boattown »

This is a diagram of the raw water impellers, right? I am talking about the fresh water pumps bolted directly on the engine block.
barkleydave
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Re: Reverse rotation engine fresh water pump connections reversed?

Post by barkleydave »

Yes. Hoses are not reversed. Direction of vanes are.

Follow Jeff diagram it is perfect.
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boattown
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Re: Reverse rotation engine fresh water pump connections reversed?

Post by boattown »

The fresh water pumps on marine engines are not directional (same pump for regular and reverse rotation motors). The vanes are straight. A car water pump is directional, though. See the images
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boat pump.jpeg
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car pump.jpg
TinLizzy
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Re: Reverse rotation engine fresh water pump connections reversed?

Post by TinLizzy »

Although he says fresh water pump, I believe he is talking about his raw water pump. But as always, I could be wrong.
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