First of all a Happy New Year to all of you! Then concerning my topic: I have 3 different high volume water pumps (ea 69 11-bolt style) to choose from for my (already with a stock 69 water pump equipped) 68 Firebird:



All three of them are aluminium high volume, using exactly the same casing made in Japan (although the one in the middle from FlowKooler has the "made in Japan" grinded out - but they forgot to grind out the part´s number on the inner side...)



On the far left side you see a Milodon High Volume WP bought from Classic Industries (part# 16281, I paid USD 99.95, now 89.99).
Here are closer pics of the rotor (I was told that´s the really important part of the WP):





In the middle it´s the FlowKooler Performance WP bought at AmesPerformance (AP part#FN258AL, FK´s own part#1649, USD 129.00!):





Finally on the RH side it´s a high volume WP bought from R.A.R.E. (part# AWP-1, USD 89.00):





So -- big question for the experts: which one´s the best??

Funny thing btw - when you look closer (could be you first have to copy and paste the pics in an extra folder to see them larger) you´ll notice that the Milodon and the FlowKooler water pumps are exactly the same (!!) except an additional welded-on inner closing plate on the FlowKooler pump. Not sure if this justifies the 40$-difference...?

I´ll use one of them together with an stainless water-pump backing plate I bought from R.A.R.E., too (part# SSWP-1, USD 35.00).

For the moment I run - as told above - a regular 11-bolt WP on my (professionally restored and slightly upgraded) 68 400 YS (GTO) block. I run a RodneyRed aluminium cooler and temperatur is borderline so I´d like to upgrade to a high volume WP together with the according thermostat.

Concerning the thermostat AmesPerformance recommends a heavy duty thermostat opening at 180 degrees (part# FN255W, USD 10.00) but ClassicIndustries recommends the MrGasket High Performance thermostat, opening at 160 degrees (part#16400, USD 14.95).

Again: Who´s correct?

Any suggestions would be highly appreciated!

This is the perfect opportunity for some experimentation. Try each of them and tell us the results. I've been wondering how these pumps perform, too. I have a concern for what happens at high RPM's, if they start really dragging on the power. You might be trading low RPM pumping efficiency for high RPM performance.

I do know the cast ones will last better than the stamped one (on the right)whick can rot out earlier causing flow issues. With that in mind, I would have some concerns of the welded on plate eventually rotting and coming loose....however with proper coolant maintenance perhaps not such a big issue....

Be interesting to see a 3 pump test tho...

People say the stamped steel impellers are to be avoided. My pump is stock with the cast impeller and I run a 160 degree thermostat. I'm very happy with that setup in Wisconsin. Somebody from Arizona may have another perspective.

I would have confidence in both the pumps you show with cast impellers. Send back the one from R.A.R.E..

Thanks for your input. Okay, two left... Now, better to choose the plain Milodon or the FlowKooler with extra closing plate? Do you see any (dis-)advantage using this closing plate (except being more expensive)? It´s very accurate welded onto the rotor and I will use the correct coolant so rotting won´t be of any concern...

I'd certainly try the one with the closing plate....however I have the cast one and it runs cool even at 36c (100F)

I have the FlowKooler in mine. If I remember when I bought it. It was suppose to help water flow above 3500 RPM. Something to do with the water direction. Ive had no problems with mine. .02

I bought the Flow Kooler a year ago, very happy with it.

The welded-on plate will cause less cavitatition, and improve cooling..

I think on chevy pumps, it's as much as 20 or 30 F cooler with closing plate vs. stock pumps..

I would use the one with longer fins.

Okay, most votes are for the FlowKooler... So I will try this one, too. Thanks again for your input!

Cheers

Thomas