I'm using a Meziere electric water pump on a 526 stroker big block (street car). The pump as well as the fan is triggered by the temp sensor.

The question is:can the thermostat be eliminated AND should I install a restrictor plate to slow down the flow through the system?

[quote=Stanton The question is:can the thermostat be eliminated AND should I install a restrictor plate to slow down the flow through the system? [/quote] That is one of those you need to try it to find out if that will work on your car or not

I would think you would want that pump running non stop to keep the coolant circulating and eliminate hot spots in the block

As far as the thermostat / washer goes testing it is the only way you'll know. I would encourage doing so with a thermocouple and digital meter
unless you're having heating issues I'm not sure what the benefit would be

I have a PRP electric pump 75 B-body stock radiator, gutted thermostat 400 race only, rarely goes over 180, rad fan on temp switch, I turn off pump to warm up engine quicker

I would run the pump all the time and the fan on the thermostat.

I personally don't subscribe to flow restrictors. As much flow as I can get.

Any reason why you are running a electric pump? Might want to convert to belt driven pump and a t stat. Waiting for the coolant in the block to heat up before the pump comes on doesn't sound so good. Temps will be up and down and won't stay at a constant operating temp.

Only time a flow restrictor makes sense to me in a cooling circuit is when engine is way over cooled and/or flow is so fast cavitation bubbles start to form, which in a closed system are near impossible to detect, but any hot spots will assist their formation. Basically, they are indications of low temp localized low pressure boiling IMO.
High pressure cooling reduces many potential issues.
I am toying with going to a 55gpm remote electric cooling system. The -20AN is rather pricey it seems.
A variable speed pump would be optimum.

what ever works best for you, with my system (race only) I can control what temp I stage at, which makes my ET's very consistent, pump stays on once I leave pit

This "too much flow through the radiator and it won't cool" is a bullstuff myth that has been around forever. You can't have too much flow. Well, unless you have too much cooling as stated by JCC. But then, a thermostat would fix that.

I wonder who started that myth? Whatever, it will never go away.

I run an electric Meziere WP105SHD water pump in my 528 Hemi on the street with an aluminum radiator with dual electric fans and a 160 degree t-stat with no issues. In fact this car runs cooler with more than double the horsepower than any of my other more stock type cars run temp wise.

Not saying you can't, but the instructions w/ the Meziere pumps say not to run a thermostat.

I am 99.5% in agreement with you.
But I still have a concern of fast moving water flow cavitating around say a tight internal corner and creating a localized hot spot, because it is getting reduced contact with a liquid, but in the big picture it would not show up on a temp gauge. I am curious how much effort design time is exerted on the water jacket for the heads.
Which gave me this idea for a test with an inject an x-ray tell tale ( much like a heart stress test nto the coolant fluid of a benched sealed head and super x ray the head under flow to see what turns up as visible voids in the fluid. Of course an x ray thru a CI head would be rather hefty item, alum a bit easier?
Maybe I have too much time on my hands.

Cavitation is very unlikely to occur in the pressurized side (downstream) of pump, and “excess” flow encountering restrictions would further increase the pressure, which would make cavitation even less likely…..

I think any "hot spot" couldn't get too bad since heat transfer to the nearest water contact would "smooth" that out. But I also think cavitation because of flow would have to be some awesome flow. And since flow and turbulence cool better, I bet it would cancel out.

In any case gang, don't think that slowing flow is a good idea.

Based on what exactly? Boats experience cavitation all the time with say 8' of head (11 psi?) and at low speeds. Not sure that is a fair comparison, but it is one.
The main point I am making, we don't precisely know I suspect.

how long have you been hot rodding?
I've had that experience you say won't or can't happen, water flowing to fast through the cooling system without a thermostat, Been there, done that
That car would cool fine 150 F to 165 F around town with no thermostat at low speeds (under 45 MPH), it would get over 230 F at cruise speeds above 55 MPH on the open roads of SO CA, the faster I drove it the hotter it would get
I put 160 F thermostats in it and it would run from 160 to 175 regardless of speed and time of day or night
that was a 1959 Dodge Coronet with a 326 C.I. Poly motor in it.

Where does it occur? On the front of the propeller is most likely. Inside the cooling system of an engine, the inlet portion of the impeller is the most likely part to experience cavitation.

I hate to disagree with you, but its not ME saying this. This comes out of the Heat Transfer study from the University of Minnesota. I have to add, U of M engineering has been studying heat transfer since 1880's and leads the world in this field. Now, as such, there is 3 possibilities to water not cooling when going fast:

1. Something else unforeseen is happening, pump inefficiency or something. Hose collapsing, some restriction.

2. The physics in your radiator are different than other radiators on this planet, and universe. (this should be examined by some scientist because this would really be something)

3. The U of M has made continuing mistakes for the last 150 years of study.

I myself stand by the results of 150 years of experience.

I wonder what item UOM was studying for their finding.

God only knows how many drag cars have restrictors in their cooling systems to slow down water flow.
My little alum-head 368" SB, small alum radiator, separate ATF cooler, electric fan & pump took quite a while to get 120 on its mech gauge from room temps.
75-deg day, pump & fan on, 120-130 in the water box, would have about 170 at return-road turnoff.
I think it may be a more complex equation than their finding, when applied to internal combustion engines...complicated further by different cooling architectures.

Hmm

Wonder why?

Flow rate is the number one variable affecting thermal transfer in a cooling system and no internal combustion engines are not a special case.

Think about how a thermostat functions and what it is designed to do.

It is designed to set the MINIMUM cooling system temperature and it does it by restricting flow, to the point of stopping it below it's opening point. Furthermore, the thermostat is NOT an on/off switch either. There is some, albeit limited in the case of a mechanical thermostat, regulation of water flow. In the case of an electronic thermostat that flow rate is computer controlled and more precise.

Flow restrictors came about, not because of cooling issues, but rather because "drag racers" were far exceeding the designed flow rate with high rpm blasts cause cooling system issues. A larger water pump pulley, or smaller crank pulley, would have fixed that issue more appropriately. But hey, monkey see monkey do, right?