plumbing flow question(s)

[Chris Kouba]

On a 302 with a V belt rotation water pump, what direction does coolant flow through the two 5/8" ports?

I know the top one is the bypass inlet, which I presume flows water INTO the water pump, so that one goes in.

Does the other (lower) one draw coolant in or push it out?

Another member was kind enough to post this diagram, which makes sense to me:

However, a different set up was recommended to me which has that lower port connected (5/8" hose) to the bottom of a high-mounted expansion tank with a 3/8" bleed line from the rad connected to the top of it. The expansion tank has a pressure cap which feeds an overflow.

This second system is up and running successfully on multiple cars, I just don't understand the flow of coolant and how it's doing its purging of air.

Thoughts?

Thanks in advance,
Chris

 

[Jac Mac]

Both 5/8" hose fittings on the water pump - the flow direction of both is into the pump- this applies to both CW & CCW pumps.

 

[EGLITOM]

Chris

As jac pointed out all connections on the waterpump suck.
Take a look at the "waterpump theory" thread.
It is correct to put a big enough exapnsion tank on the highest point. run a 5/8 from the bottom of this tank to one of the inlets of the pump and defenitely run another 5/8 from the thermostat bypass to the pump.

In terms of purging the air out of the system. run a AN3 line (max) from the top of the radiator into the expansion tank and another AN3 line from the rear of the engine to the expansion tank. you could also "T" in another AN3 line from the top of the thermostat housing into the AN 3 line coming back from the rear of the engine or do what others and me have done. drill a 3mm hole into your thermostat as far outward as possible and locate this hole in 12 o clock position whent mounting it.

Where possible avoid 90° elbows in your main cooling line ( although i have done it) upfront.

Reco is also to choose your WP drive ratio that way that WP is running app 80% of crank speed.

you can see how i´ve done it here

TOM

 

[Chris Kouba]

Thanks Tom and Jac.

I will poke around a little more regarding the size of bleed line from the rad. Worst comes to worst, I will turn a restrictor and stick that in the nozzle to impinge the flow.

I did take a look at the water pump theory thread as well... Interesting reading. Thanks for the direction Tom.

Chris