O.K. CRD Owners:

I received a more detailed reply from Jerry at Meziere Enterprises. I will start with my e-mail to him, (sent Saturday, June 19, 2021), asking for more detail, and follow up below with his more detailed reply, (sent Monday, June 21, 2021)...

JEFF BAUER:
"Thank you very much for your prompt review and reply to my concerns. I am always trying to learn more and do right by my customers by manufacturing the best product possible.

I had never considered any kind of pressure other than the static pressure an enclosed cooling system develops as a result of the heat that it absorbs from the engine when it is running. I believed that Pascal's Law was the only principle at work in cooling systems and that any pressure generated in a cooling system would instantly be transferred to the entire volume of coolant in that enclosed volume. I previously dismissed discussions regarding dynamic pressure developed by the water pump because I thought it was a myth, backed up by what I had found out online and by my own understanding of the differences between a positive displacement pump vs. a volume pump. The following is what I pulled up on GOOGLE...

"Water pumps are not positive displacement pumps. The water pump is a centrifugal pump that can move a large volume of coolant without increasing the pressure of the coolant. The pump pulls coolant in at the center of the impeller."

In reading over the BangShift.com article I sent you previously made me reconsider my previous beliefs that pumps are almost entirely volume OR pressure, (to be precise, my previous belief was that a positive displacement pump was approximately 90% pressure and 10% volume and a volume pump was approximately 90% volume and 10% pressure). It now seems that either type of pump can create a considerable amount of both volume and pressure, although the positive displacement pump is specifically designed to create pressure and a volume pump is specifically designed to move fluids.

Please provide feedback to what I have written above... am I much closer to the truth now? Accuracy in providing information to my customers is important to me, as well as admitting any mistakes I have made. Please also pass this correspondence to other technical support people at Meziere Enterprises for their feedback as well. Specifically, can you and your colleagues, (perhaps Mr. Don Meziere himself?), tell me if I finally have my facts straight, especially about the following...

1) PLEASE RESPOND TO THE FOLLOWING STATEMENT: Both types of fluid pumps - positive displacement and volume pumps - create significant significant amounts of both pressure and volumes of fluid moved. However, the specific design of positive displacement pumps is for the primary purpose of creating pressure and the specific design of volume pumps is for the primary purpose of moving fluids. The secondary purpose of moving fluids in a positive displacement pump and the secondary purpose of creating pressure in a volume pump are a natural outcome of the design mechanisms and are necessary for either type of pump to be identified as a pump. Each type of pump has its strengths and weaknesses and are used almost exclusively for their primary purposes. Please comment on this if you can; let me know if I finally nailed the basics here.

2) PLEASE RESPOND TO THE FOLLOWING STATEMENT AND QUESTIONS: The following question is in regards to the specific question I asked previously about dynamic pressure in a cooling system and problems that occur when poorly thought out changes are made in the cooling system.

a) Can you or anyone at Meziere Enterprises tell me if cooling system inefficiencies that have been diagnosed as coolant pump dynamic pressure problems are in the exclusive realm of highly modified competition engines with extremely high specific power outputs?

b) Has this phenomenon ever occurred in engines that are completely original equipment with the same mount of power, (both horsepower and torque), that was specified by the original manufacturer?

c) How about engines that have had some performance modifications with or without changes to the cooling system, with increases in power as much as double what the original manufacturer specified?

d) If indeed dynamic pressure problems only occur in engines with a high specific power output, at what point, (specific power output), do dynamic pressure problems become apparent?"


JERRY DICKINSON:
"HI Jeff:

It's pretty busy around here but I will do my best.

Question 1) Yes your understanding is correct.

Question 2) Meziere's is known for our 12 volt electric pump, The concern in the article was that a relatively low power 12 volt electric water pump will create almost no pump pressure. In applications such as towing, boats or boost application where the engine will see heavy loads for extended amount of time, like 10+ minutes a Mechanically driven pump with a lot more HP spinning it will spin much faster which will create a lot more water flow and pump pressure.

A stock engine with its mechanical driven water pump will deliver the flow and pump pressure the engine needs as the engine RPM increases. As this relates to your product you may see a very slight pressure drop but you would also see a increase in flow. And to be honest I doubt you would even be able to measure the difference if you had the instrumentation to measure it.

The only issues we have had with pump pressure has been primarily with extreme high boost application, we are talking 30+psi on gas and 60+ on diesel engines. Again in a lot of these application replacing our electric pump with a stock mechanical driven pump will solve the problem.

In stock or even mildly upgrade performance engine using the stock water pump seems to be adequate, often the customer will add higher flowing thermostat."