Water pump question-reverse rotation

driftwood · 07-19-2009, 11:15:22 PM

I was wondering if there is any reason I can't run a reverse rotation waterpump such as used late 80's on? Seems to me having the coolant go to the heads would be a better way of cooling and GM must have had a good reason for it.

I have a moroso electric waterpump drive so all I would have to do is reverse my polarity. Is there anything else that I am overlooking?

Thanks, Joe

Jer · 07-19-2009, 11:28:24 PM

Thermostat

GetMore · 07-19-2009, 11:30:51 PM

How about the biggest issue with just spinning it backwards, which is the fact that yu will be trying to pull coolant from the top of the radiator instead of the bottom.

Next might be the thermostat, not sure how that would react to pressure from the other side.

Another issue is the possibility of cavitation. The system is designed so the pump pressurizes the block. It pushes coolant. If you try to run it backwards you will be sucking the coolant, lowering the static pressure in the block, which can cause cavitation at the pump and an increased possibility of the coolant flashing to steam.

Now, all that being said, I think there is a way to modify the system to run reverse cooling. I haven't got a clue what it takes, but it can be done.

FWIW, when GM went to reverse cooling they made more changes than just pumping the coolant in the opposite direction. It's not that simple.

Todd80Z28 · 07-19-2009, 11:53:12 PM

As noted, reverse rotation does not equate to reverse flow.

hhott71 · 07-20-2009, 09:55:50 AM

The Reverse rotation pump spins backward because of the belt set up. The serpentine belt routing makes the water pump spin in the opposite direction as was normal. The impeller and corresponding internal shape witch compliments the CCW rotation still has its out put ports flowing like the standard rotation pump.

tom3 · 07-20-2009, 10:46:34 AM

Have to go with the late LT1 type pump to get actual reverse flow, not an option for the early engines. Good plan in theory though.

driftwood · 07-20-2009, 05:53:18 PM

Guys, thanks for setting me straight.I feel like a tard now.

I was thinking of "flow" when reading "rotation", this is where I got into trouble down the wrong path.

So then I can run a reverse rotation pump with the electric drive reversed and will have normal flow... correct?

Note to self-think before leaping!

Joe

GetMore · 07-20-2009, 08:38:39 PM

Yes, you could. Don't know why you'd want to.
I'm guessing you just wanted to check and see if you understood how it would work?

driftwood · 07-20-2009, 10:27:25 PM

Quote:

Originally Posted by GetMore

Yes, you could. Don't know why you'd want to.
I'm guessing you just wanted to check and see if you understood how it would work?

I actually was wanting to use reverse "flow" not "rotation" so the coolant would go to the heads first in theory cooling the hottest area first. This all stemmed from me being in the midst of installing my engine and having a reverse rotation pump on hand, thinking of using it.

However, I wasn't thinking clearly/thoroughly and mistated the question. I also did more digging and now understand the reverse flow better. Through the help here, I found my answer and will just use the reverse rotation pump which I know fully understand will not affect direction of flow(where I originally went wrong).

So thanks to all who chimed in, I appreciate it.

Joe

Lowend · 07-21-2009, 12:23:24 AM

In a word - don't
not worth the hassle

MEAN79 · 07-21-2009, 12:36:34 AM

You could always buy a setup. that mounts under the water neck that has two lines running out of it. And you drill and tap the heads and run the line to the heads. It will help cool the heads better.

Just a thought