[chuckies76ta]

Question on Electric water pump. I installed one on our 505 cu in. I wondering what the consensus is in regards to leaving the thermostat in? I'm running a 160 deg thermostat.
A racer friend say to remove the thermostat or it would burn out the pump.
My thinking is would be nice to leave thermostat in so engine warms up quicker and we can always cool it down at the track to 160 with pump and fans. We do run electric fans. I do have some of the thermostat restriction plates to try also.



Thanks in advance for any advice.

[Steve C.]

Years ago I spoke with Jay Cason at Meziere and was told not to run a thermostat. I never have. Since then I've seen various conversations regarding this and with mixed opinions.

Some suggest remove the thermostat and install a plate restrictor. Don't run the water pump dead headed.

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[Scott65]

You could always do both. Pull the Stat, and have the pump only come on after 140-150.

[chuckies76ta]

Thanks Steve. I would take that advice as pretty solid. Now to wonder why.

[chuckies76ta]

Thanks Scott. Didn’t even cross my mind duh. Lol. Anyhow, I have it setup on a relay to turn pump on as soon as engine starts and then I have a switch to over ride when engine off to cool it down after a 1/4 mile run. I haven’t tested yet so I’m not sure how the setup is gonna work. Had no issues with heat with mechanical pump and 160 thermostat last season.
Thanks for info.

[Scott65]

I forgot to mention, if you're temperature probe is in the intake crossover, start lower to verify. Temps in the block and temps in the intake crossover will be different with no circulation. Maybe have it turn on at 100, and see what you get.

[Steve C.]

Both my water pump and dual radiator fans are controlled by a on/off switch. When driving the water pump runs continuously.
The fans cycle on and off at a predetermined temperature. I have it written down somewhere, but if memory serves me right the fans come on at 185 degrees and off at 165 degrees.
In my case they are controlled by my fuel injection ECU with a sensor on the intake manifold crossover.


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[Steve C.]

Opinion off the internet....

You really need to keep the water moving at all times, even if it's just recirculating in the block as the existing system does when cold. One good reason for setting it up this way-- it minimizes hot spots, and the circulation warms up the block more evenly than would be the case with no circulation.

That said, some control the pump speed based on RPM and/or Temp Differential so you still need a controller for that.


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[misterp266]

Following as I will be using a Meziere remote pump on my build.
I was thinking of adding an 8AN bypass hose from the crossover to the pump inlet side. I’m using a Moon front cover. May also add a couple of small holes in the thermostat. I have read that Meziere pumps don’t like PWM controls and also should not be deadheaded. And as Steve stated, water should be circulating all the time to prevent hot spots.

[punkin]

I apologize if this is inappropriate. I don't mean to hijack the exchange but I may be learning something new here. I have installed a Merziere water pump with a 180 thermostat. Is this a bad thing given the t-stat will be closed until temp comes up? Is this bad for the pump?

[AG]

I run a 160 F T-stat in my race car with a Meziere electric water pump and it works fine.

[chuckies76ta]

Originally Posted by punkin

I apologize if this is inappropriate. I don't mean to hijack the exchange but I may be learning something new here. I have installed a Merziere water pump with a 180 thermostat. Is this a bad thing given the t-stat will be closed until temp comes up? Is this bad for the pump?

No worries. We value everyone's help.


Check Steve post #2, what Jay Cason at Meziere and was told not to run a thermostat.

[chuckies76ta]

Originally Posted by misterp266

Following as I will be using a Meziere remote pump on my build.
I was thinking of adding an 8AN bypass hose from the crossover to the pump inlet side. I’m using a Moon front cover. May also add a couple of small holes in the thermostat. I have read that Meziere pumps don’t like PWM controls and also should not be deadheaded. And as Steve stated, water should be circulating all the time to prevent hot spots.

Ya, I left my water bypass in use so the water does move into timing cover to pump. I have the thermostat removed as of now and well see how it works when weather changes here.
Right now I have plumbed back of heads to water crossover. I already have somewhat of a restrictor in place. I have an adapter plate on the crossover that divide the front and back water flow.

Adapter http://www.precisionautomotivespecia...Manifolds.html

[chuckies76ta]

Originally Posted by AG

I run a 160 F T-stat in my race car with a Meziere electric water pump and it works fine.

Thanks for the info. Are you still running the bypass?
I'm still wondering why Meziere rep would say not to run a thermostat. I understand that if you do remove thermostat that they want a restrictor plate in place to slow water volume down to the rad.

If a thermostat is installed and nothing else changed from stock setup, the electric pump is not dead headed. It does the same operation as a mechanical pump. Am I right or wrong? I understand that if the thermostat is removed, that a person can cool the engine down to basically temp outside if run long enough. What I'm alluding to is that with the thermostat installed, you'll only cool engine to thermostat setting. Say 160 deg. You won't cool engine down any further. If thermostat is removed you could cool engine down to like 120 deg. or possibly lower. I'm wondering if that is the only reason to remove the thermostat once an electric pump is installed?

[Mike Davis]

Mike Meziere buys CNC machines from us that he makes these pumps with, I have 2 of his pumps on different engines. He and I had a long discussion about this. He felt it was hard on the pump motor when the thermostat was closed. He felt there was no need to run a thermostat. I run a gutted Thermostat as a restrictor ring on my 66. Car runs about 180deg when I drive it on the road with a block filled to the bottom of the freeze plugs.

[R 70 Judge]

I went from no thermostat to a 160* thermostat in my TA and it seemed to consistently run cooler on the street, but I also changed the radiator cap to a higher pressure unit at the same time so I honestly don’t know which helped. I hit 200*-205* on the street briefly before the change with no thermostat. Got up to 185* with the updated 160* stuff. I’m running a meziere pump as well. It’s funny this thread came up because I was just thinking about pulling water from the back of the heads like this first set-up posted to see if it would help.

[chuckies76ta]

Originally Posted by Mike Davis

Mike Meziere buys CNC machines from us that he makes these pumps with, I have 2 of his pumps on different engines. He and I had a long discussion about this. He felt it was hard on the pump motor when the thermostat was closed. He felt there was no need to run a thermostat. I run a gutted Thermostat as a restrictor ring on my 66. Car runs about 180deg when I drive it on the road with a block filled to the bottom of the freeze plugs.

Thanks Mike. I also have taken a thermostat and gutted it for testing when car is back on the road. Thanks for posting.

[chuckies76ta]

Originally Posted by R 70 Judge

I went from no thermostat to a 160* thermostat in my TA and it seemed to consistently run cooler on the street, but I also changed the radiator cap to a higher pressure unit at the same time so I honestly don’t know which helped. I hit 200*-205* on the street briefly before the change with no thermostat. Got up to 185* with the updated 160* stuff. I’m running a meziere pump as well. It’s funny this thread came up because I was just thinking about pulling water from the back of the heads like this first set-up posted to see if it would help.

Thanks for posting info James


I initially ran the hoses from back of the heads to the intake crossover and also run one to the return on the water pump bypassing the heater core. That was this past summer with a mechanical pump. We ran a 160* thermostat, and the hottest the engine got on the coolant gauge was 170* -175*. We still have the same radiator from other engine that was 600 hp. This combo is 789 hp and 700 torque. 505 cu in.

I just installed the electric water pump this winter and I also removed the return to the water pump that is for the heater core. I figured if no thermostat used that there is need to feed water pump return. I blocked this one off.
Again, I haven't tested any of this yet with new electric water pump. My only concern at this point is getting the engine up to temp with no thermostat installed. I like the way it ran before with mechanical pump. I went to a serpentine setup as we were having trouble throwing P/S belts. I figured at the time I would install electric water pump an would assist in coolant engine after a run.

I have the hoses setup like your first pic.

[BDHABT]

Ran a 55gpm Meizere water pump for ten years with a thermostat,never an issue.

[AG]

Originally Posted by chuckies76ta

Thanks for the info. Are you still running the bypass?
I'm still wondering why Meziere rep would say not to run a thermostat. I understand that if you do remove thermostat that they want a restrictor plate in place to slow water volume down to the rad.

If a thermostat is installed and nothing else changed from stock setup, the electric pump is not dead headed. It does the same operation as a mechanical pump. Am I right or wrong? I understand that if the thermostat is removed, that a person can cool the engine down to basically temp outside if run long enough. What I'm alluding to is that with the thermostat installed, you'll only cool engine to thermostat setting. Say 160 deg. You won't cool engine down any further. If thermostat is removed you could cool engine down to like 120 deg. or possibly lower. I'm wondering if that is the only reason to remove the thermostat once an electric pump is installed?

I still run the by-pass and can quickly cool the engine down to below 160 F using the water pump and fan. I come back to the pits, cool it for 5-10 min and I'm off again.