Waterpump theory

[Jac Mac]

This pump & this cover 'look' like they will really work together, even the pressed steel impellor ( lower RH corner of pump pic) looks slightly better than the multipiece thing that Ron Earp had fail in the 13 hr race, but yes a decent cast or cnc impellor with CCW vanes would be an improvement.

Amusing is it not, that after nearly 40 odd years that they have gone full circle and arrived back with a CCW pump that is virtually a mirror image of the 1965 pump....all it needs is the cast impellor... and perhaps a modern day hi-tech coating in the front cover to deter cavitation erosion etc

 

[EGLITOM]

Howard

good that your system fullfills all the things me think is good ( up to now noone had to say something against it).
That leads to the conclusion that the pump in fact is crap. Your engine is not revving to high
and thus the pump is not spinning to fast. but give it a try with a 80% underdriven ratio and a different brand pump. Read trough the cover post and make up your own opinion about the flow efficiency of this kind of pumps and cover you are using.
I personaly prefer the old style or 95-96 cover, because it think it is the better flowing setup.
It is more critical of course if it experiences cavitation, because any abrassion will go directly to or from the cover housing.

Thanks
TOM

 

[Ian K]

I am personally contemplating a remote mount (or even radiator mount) Meziere constant flow 55 gpm pump (want to save as much space in front of the engine as possible). This would conflict with either the surge tank being placed as high as possible (the front of the car is too low if I go with a radiator mounted pump) or placing the surge tank as close to the pump input as possible (again, I would have to place it in the front for a radiator mounted pump).

This leads me to look at mounting the pump near the surge tank on the firewall (since this seems to be the best/highest location for the surge tank), but I am thinking that wouldn't be a great idea.

So, I will probably go with either a radiator mounted pump, or a remote pump somewhere up front, keep the surge tank where it belongs, and hope that the constant flow 55 gpm will suffice. I also want to "reverse" flow, having the coolant supply the heads first, and then flow down through the block before returning to the radiator.

Any comments/thoughts?

Ian

 

[EGLITOM]

Ian

Don´think there is a conflict. The surge/expansion tank is just working as a unit applying prepressure. If you make the feedline from the expansion tank big enough ( 20mm id), you could place it on the fire wall in a high position and run the feed line towards the front of the car where your pump is located .
Also i would think twice about the pump choice. Take a look at the Davis Craig product line. Don´t let yourself misslead by the 55 GPM volume of the meziere, this is free flowing value. Have not seen a flow/pressure diagramm on their website.
DC is offering a nice package either in Nylon and aluminium with an electric control unit which actually is varying the speed of the pump and controlling your fans as well. This way the pump is only running the required speed thus minimizing also the chance of running in cavitation mode all the time. It also runs the pump automatically after engine stop to avoid heat soak.
Electric Water Pumps
TOM

 

[Ian K]

Ian

Don´think there is a conflict. The surge/expansion tank is just working as a unit applying prepressure. If you make the feedline from the expansion tank big enough ( 20mm id), you could place it on the fire wall in a high position and run the feed line towards the front of the car where your pump is located .
Also i would think twice about the pump choice. Take a look at the Davis Craig product line. Don´t let yourself misslead by the 55 GPM volume of the meziere, this is free flowing value. Have not seen a flow/pressure diagramm on their website.
DC is offering a nice package either in Nylon and aluminium with an electric control unit which actually is varying the speed of the pump and controlling your fans as well. This way the pump is only running the required speed thus minimizing also the chance of running in cavitation mode all the time. It also runs the pump automatically after engine stop to avoid heat soak.
Electric Water Pumps
TOM

Thanks for the reminder/advice Tom, I had forgotten about Davies-Craig. And I agree - DC's variable speed looks to be a better option.

Of course, all your points about cutting down on length of the pipe runs, keeping turns and transitions to a minimum, and looking for 45 degree turns instead of 90 degree ones wherever possible, is very important.

Ian

 

[Mike Trusty]

Here is a little experience or recommendation for what it worth.
Since I started recommending the arrangement that I'm going to describe there has been numerous Pantera, Ferrari, Lamborgini and three GT40's that have applied this system. It has been written up in the Pantera Club publication so I don't know how many have been applied. The bottom line is that I have never heard of it not solving all of the cooling problems. <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com

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1. Use a "constant" flow electric water pump. All of the above use the Miezere pump but there are other pumps available. Do not use a variable flow on the pump. This is critical to insure that you don't develop steam pockets in the heads when the pump thinks that the water is cooler. I don't recommend the reverse flow that has been mentioned. There are published advantages with using non hydronic coolants but it isn't needed and complicates air removal from the engine. Remember that water has a coefficient of one. There is no other fluid that is that high. You will never again have a problem with high speed cavitation.<o></o>

2. The pump can be mounted in the conventional location or remote.<o></o>

3. The key to proper pressure in the system is that the fill line from the pressure tank MUST extend to the suction side of the pump. If the pump is on the motor there will be a fitting available on the pump that is normally used for the heater connection. Note that the heater line will not be connected at this point. I'll discuss the heater recommendation later. If the pump is remote the line from the high firewall pressure/fill tank must be extended to the pump where ever it is. One of the GT40's mentioned lives in Houston and drive in stop and go summer traffic and has the pump located just behind the radiator. The line that was originally used for the heater return is now the line between the pressure tank and the suction side of the pump.<o></o>

4. Forget about the GPM ratings of these pumps. As pointed out they are rated at 55 gpm but that is not what will be flowing. You can look at pipe size/flow charts and do tests that will show the real gpm is around 20.<o></o>

5. Remove the thermostat from the motor. If it has an internal bypass like a Cleveland, plug it. If it is external plug/cap it.<o></o>

6. Install a full flow bypass type thermostat in the front just behind the radiator that will either bypass all or part of the engine water back to the return to the pump or route it through the radiator depending on the water temperature.<o></o>

7. If you have a closed car like a Pantera use a water/oil cooler located in the discharge coolant line from the motor. This will help preheat the oil. Not needed in a GT40 where air can be routed to an air/oil cooler.<o></o>

8. Extend a #3 line from the highest point on the engine(normally the top of the empty thermostat housing) to high on the pressure tank. This will allow air to migrate back to the pressure tank with the minimal flow that will always be there.<o></o>

9. Install at least a quart size expansion tank connected to a relief/return type pressure cap on the pressure tank. Extend this line to the bottom of the expansion tank and place as close as possible to the same height as the pressure tank. A 14 lb cap will be plenty. Fill the system completely up to the pressure cap and insure that all air is out of the system.<o></o>

10. Use a time delay relay that continue to run for two minutes after the engine is shut down. This relay will run the pump and the radiator fans to prevent heat soak. This can get complicated with pulse width controllers on the fans but do not use them on the pump.<o></o>

11. Put two heater hose connections on the return line from the engine just before the bypass thermostat mentioned above. This is behind the radiator. These connections are on the same line and as close together and you can weld them. Connect a heater hose to the first connection coming from the motor with a ball valve and connect to the suction side of either a MB or DG small heater pump. The valves are there so you can isolate the heating system during motorsport track events. Extend the hose from the pump to the heater core and from the heater core to the other connection with another ball valve that is right beside the other. You can choose if you want a control valve or not keeping in mind that there will be NO water flow through the heater if the small heater pump is not running.<o></o>

12. Control the radiator fans from the temperature ENTERING the radiator NOT the leaving temperature as most will recommend. I'm assuming that you have a good fan system. A big mistake sometimes is the use of too restrictive fan shrouds. I removed the shroud that was furnished from SPF and mounted the stock fans directly on the back of the open radiator and then fabricated a duct to connect to the front deck opening. Works great.<o></o>
<o></o>

Sorry for the long description but it really is abbreviated. The other two GT40's are active on this forum and I hope will chime in.<o></o>

 

[Terry Oxandale]

9. Install at least a quart size expansion tank connected to a relief/return type pressure cap on the pressure tank. Extend this line to the bottom of the expansion tank and place as close as possible to the same height as the pressure tank. A 14 lb cap will be plenty. Fill the system completely up to the pressure cap and insure that all air is out of the system.

Mike,

I've planned (built) everything as you've noted above with the exception (or confusion) regarding the quote above. It appears you're using two tanks, one pressure tank, and one expansion tank. I fully understand the expansion tank, and planned on plumbing that back to the suction side of the system through as 1.5" OD, 6" tall, vertical plumbing stub off the main coolant plumbing, and capped off with a pressure cap (the expansion tank being about 12" above this stub). I'm not understanding the required pressure tank. Can you expand (sorry, no pun intended) on the pressure tank's need, purpose, or requirement that the my plan (omission of the pressure tank) above will not provide?

Terry

 

[Jack Houpe]

:thumbsup: Yepper, I agree with Mike

Terry, not speaking for Mike but there is only one tank in my car.

 

[Ian K]

Mike,

I am curious as to why you do not recommend reverse flow?

Ian

 

[Mike Trusty]

Terry:

It is probably my use of terms.

What I'm calling the pressure tank is the tank that is typical to GT40's that has the pressure(radiator) cap on it. This the tank that a line extends from the bottom of the tank to the suction side of the pump. The goal is to set the point of zero pressure change in the system that is controlled by the pressure(radiator) cap to be at the lowest pressure point in the system which is the suction of the pump.

What I call an expansion tank is a tank that is vented to atmosphere at the top with either a vented cap or simple overflow line extending to somewhere behind the rear tires. Think about that for a minute and you will figure out the reason to put it behind the tire. The line going to this small tank extends from the relief line outlet just below the pressure cap on the "pressure tank". The relief line goes to the bottom of the vented expansion tank. Note that I said to FILL the system completely up to the pressure cap and have no air in the system.

Because of this as the water heats up it expands and must go somewhere. The overflow type radiator caps relieve this "expansion" to the small "expansion" tank raising the level of the fluid in this tank based on the volume of water in the cooling system and the temperature rise.

Now with the proper pressure(radiator) cap with the check valve as most are the water will return to the pressure tank as the system cools because of suction.

There are two basic reasons for making sure that the system has no air in it. One is that it will not return all of fluid if there is air in the system. But the main reason is to help prevent corrision. Keep in mind that it is the air that you are circulating in the system that causes corrosion in your engine and radiator it is NOT the water. If there is no air in the system there will be no corrosion.

Now that said, you can opt to not provide the "expansion" tank like Jack mentioned and let the water level in the "pressure" tank set at a level that will allow for the required expansion in the system.

 

[Mike Trusty]

Ian:

THe main reason is that you have a harder time at getting air out of the system. With reverse flow the water is trying to go down from the heads to the block while any air in the system is trying to go up. Sure it will finally perk up to the top of the heads but you will need to put in multiple vent lines back to the "pressure" tank or keep bleeding the high points until you absolutely have all of the air out which realisticaly you can't do. Plus these little pockets of air are the perfect points to produce steam because the air works as in insulator between the head metal and the coolant. When you start to produce steam in small pockets this expansion causes pressure to surge in the system that will force water out the relief on the pressure(radiator) cap. This then compounds inself and causes more expansion and results in overheating.

There are definite thermal advantages to reverse flow but everything must be perfect. The point is you don't need it if you have a proper system so why complicate things.

 

[Kirby Schrader]

Since Mike has mentioned 'a GT40 that lives in Houston', I'll lay claim to that description. I used Mike's system and applied it to both my GT40 and my Pantera.

The system has been applied to several Panteras in the Houston area (I can count 5 for sure, might be more) and nobody has any problem with overheating. My son and I plan to implement the same system on the Pantera he is restoring.
Each guy has implemented it slightly different, but the basic premise that Mike has explained is the same.

GT40
I have a Meziere remote electric 55gpm pump mounted behind the radiator up front with two braided lines running back to the block. These are nice. Turn the key on to bleed the system. You don't even have to start the engine. I also have a perfectly flat firewall. No bump inside the car.
The electric pump runs full blast all the time. Even at idle where a mechanical pump pumps less.
I used the heater hose that was already there and hooked it to bottom of the 'pressure tank' that's on the right side of the SPF MkII's already. Just as Mike has described.
I have an expansion tank mounted up front on the left which uses the old radiator bleed hose that SPF had connected to the pressure tank. I just have a brake caliper style bleed screw on the radiator.
The only thing I haven't done is the shroud modification. If I sit long enough in 105F standing traffic with nothing but exhaust fumes going into the radiator, I will see the temp gauge rise slightly. Once I start moving, it drops immediately, so I know I just need to improve the fan air flow.
By the way, I believe that the wiring is generally about two gauges too small in the SPF's. I get a 2 volt voltage drop from the fusebox to the driver's side door on the A/C system. I also get almost 2 volts drop to the radiator fans. My plan is to re-wire these with larger wire and get some more oomph to the fans. I expect things to improve.

Oh... and although I have the heater hoses in the GT40 hooked up with cut-off valves, I've not installed the small heater pump yet. It just doesn't get cold enough often enough to force me to do it. Besides... drive a GT40 for awhile and your back warms up nicely anyway.

Pantera:
The general cooling mod is documented on the Space City Panteras website. (I'm the 'website guy' for the club, so if you have any complaints or suggestions, let me know)

http://www.spacecitypanteras.com/Technical/Pantera_Cooling-JTaphorn.pdf

and

http://www.spacecitypanteras.com/Technical/pantera_coolant_flow.jpg

This describes a system with a mechanical pump, but an electric one could certainly be used.
The only thing I haven't done on the Pantera is the heater hose and pump. Haven't gotten around to that yet.
The only way I can get the car to even start to overheat is be in 100+ temperatures and stop and go traffic and forget to turn on the manual second fan on the radiator. Switch it on and the temperature drops immediately.

Bottom line? I'm happy with the setup on both cars and, like I said, plan to implement it on another Pantera, too.

Regards,
Kirby

 

[Clayton]

Dug up some old articles on cooling systems. A friend purchased one of these pumps and the bronze impeller was very nice indeed. He fitted it to a 460 in a hotrod and it never ran hot.

Clayton

 

[EGLITOM]

Great read Clayton

Thanks
TOM

 

[Woody]

Hi Guys
I know this is an old post but after reading through it I would like some feed back from those who have mastered it. On my proposed cooling system I have a front mounted waterpump with a bypass themostat.
And like Tom and Mike said the expansion tank's bottom hose goes to the suction side of the pump (at least thats how I read it.)
Attached is a modified drawing of a diagram I found in another thread
Is this how Mike Trusty explained it or am I missing something.
Any / all feed back welcome
Thanks
Woody

 

[Jack Houpe]

Good choice, I've had that system for years in many cars, including F and L cars.

 

[Kirby Schrader]

Hi Guys
I know this is an old post but after reading through it I would like some feed back from those who have mastered it. On my proposed cooling system I have a front mounted waterpump with a bypass themostat.
And like Tom and Mike said the expansion tank's bottom hose goes to the suction side of the pump (at least thats how I read it.)
Attached is a modified drawing of a diagram I found in another thread
Is this how Mike Trusty explained it or am I missing something.
Any / all feed back welcome
Thanks
Woody

Woody,

Almost identical to my installation except I do not have the bleed lines on the back of the heads.

I also have the overflow going to another tank as I described in my previous message and Mike describes before that.

Regards,
Kirby

 

[Woody]

Jack / Kirby
Thanks guy's for the feed back. So I can now finish off the cooling system and yes I will use a catch can from the expansion tank.
One last question. The heater hoses, as per the last drawing or should they come from the return line only?
Thanks
Woody.

 

[Jack Houpe]

Jack / Kirby
Thanks guy's for the feed back. So I can now finish off the cooling system and yes I will use a catch can from the expansion tank.
One last question. The heater hoses, as per the last drawing or should they come from the return line only?
Thanks
Woody.

The heater hose should come off the input to the bypass thermostat (hot water out of engine), but I didn't have room for the tubing so I put it on the output of the thermostat (input to the radiator when thermostat is open) this way your getting the hottest water going to your heater. Mine both come off the same line in my set up and I use a M Benz small heater pump you can buy on EBAY. Believe me when I say your not going to need much of a heater in your car but I have my foot well sealed off from the radiator so well my feet get cold in the winter.

 

[Woody]

Thanks Jack
I'll find a small pump for the job. My air-con has a built in heater, not that its cold here but realy to demist the windscreen since I can't roll the windows down.