I Installed a Davies, Craig Electric Water Pumps on our 1929 Model A Ford Speedster
I was building our Model B engine with a Vintage Riley 4-Port Head, I realized that I had a problem finding or repairing the original Riley Water Pump. I had thought that the Riley used a Model B Water Pump (I’m smarter now), and while the Riley Water Pump looks similar, it is much larger than a Model B pump. The Riley Pump core was good but finding the parts to rebuild it would be challenging if not impossible, and I would still be using an 88-year-old water pump and nearly a 100-year-old cooling technology.
My next option was to use a modified mechanical water pump from another vehicle or use an Electric Water Pump. A drawback of a mechanical belt driven water pump is that it runs at a speed based on the engine RPM regardless of the engine temperature and cooling requirements. With a vehicle travelling at high speeds, the engine requires less cooling as ram air is assisting engine cooling, however the engine speed is higher, and the mechanical water pump is providing high coolant flow and using more engine power. In heavy traffic, or in my case, mountain driving, the engine is running lower RPM and the pump is not providing adequate coolant flow, not efficiently cooling the engine. Drag Racers and Performance guys have been using Electric Water Pumps for years to save horsepower, provide water flow to cool the engine while is not running and possibly to save weight. Based on these factors, I began reviewing the available electric water pumps.
I chose the Davies Craig Electric Water Pumps (Made in Australia, available in the US at Summit and Jegs) because they are readily available, and the electric pump does not rob any horsepower from the engine, and they provide the correct coolant flow based on engine requirements, not RPM. I used the Electric Fan because it is much safer, does to take power from the engine, and is only in operation when needed. The Davies Craig Electric Water Pumps are available in flow rates (rated in Gallons/Minute) of 21.1. 30.4, 37.2 and 39.6.
There is a chart on the Davies Craig Web Site: https://daviescraig.com.au/electric-water-pumps to help identify the correct size pump based on the engine size and application. They, and their operating Temperature for the 21.1 gal/min pump is -4 °F to 248 °F , and for all their other pumps it is -40 °F to 268 °F and pumps weigh from 2 to 2 ½ pounds. The prices for the pump alone range from $150 to $190 and for the kit with the Electronic Controller range from $340 to $400. Davies Craig EWPs are available for 12 Volt or 24 Volt operation, they are not available for 6 Volt systems.
The Davies Craig Controller is a microprocessor with a display, that is 2 9/16" wide white-on-black LCD screen displays system status (including temperature set point, pump, and fan on/off, and warnings) and doubles as a coolant temperature gauge. Single-button programming makes it quick and easy to change the target temperature at any time. You can set the target temperature in 1° C increments from 40° C to 100° C (104° F to 212° F). Davies Craig also provides Electric Fans, however any electric fan can be used if it is wired correctly. With the Digital Controller, the speed of the pump is managed by the controller which both varies the speed of the pump faster or slower and the actual run time, based on the selected target temperature. The Controller is pre-set to 185° F from the factory as the target engine coolant temperature. I reset the target temperature to 170° F for this engine. Davies Craig recommends that the setting be 9° F above the normal thermostat for the engine where the controller is installed. When the ignition switch is initially turned on, the pump will run a self-test to check the pump, and sensor connectivity, then will run at half-speed (15.2 gal/minute), at a rate of 10 seconds on, and 30 seconds off until the water temperature reaches 36° F below the set target temperature. Once that temperature is achieved, the controller will run the pump at half speed , 10 seconds on and 10 seconds off until the water temperature reaches 9° F below the targe temperature. The controller will then monitor the water temperature and adjust the pump speed from 50% to 100 % to the maintain the target temperature independent of the engine speed. The Digital Controller will operate the engine’s electric fan automatically (if installed and wired to Controller via a relay) once the engine has reached 5°F above the target temperature. Another benefit is that the Controller allows the Electric Water Pump and Electric Fan (if installed) to run after the engine is turned off for either 3 minutes or until the water temperature reaches 14°F below the target temperature to properly cool the engine.
I installed a Davies Craig EWP115 (Nylon) (Part #8930) 30.4 gallons/minute Volume Pump and Controller (EWP 115) on our Speedster which has a Model B Engine (215 cu in), an original Riley 4-Port Head, Isky cam, Electronic Ignition and two 45 DCOE Carburettors. During my installation, I used the front part of an existing Model A Cooling Pipe and hose to the radiator, then attached the hose to the pump and installed a Water Temperature Gauge Sensor to monitor the Coolant Temperature as it enters the engine. The Water Temperature Sensor for the Digital Controller (supplied with kit) is installed in the upper radiator hose to measure coolant temperature as it leaves the engine. The pump is installed in the lower radiator hose and is not hard mounted to the frame or engine. During the installation, the existing water pump will need to be removed or bypassed so it does not interfere with the new cooling system. Any thermostat will also need to be removed.
The Davies Craig Water Pumps and Kits with the Controller can be ordered from
- Jegs: (https://www.jegs.com/webapp/wcs/stores/servlet/SearchResultsPageCmd?q=davies+craig&storeId=10001&catalogId=10002&langId=-1 ) or
- Pegasus Auto Racing Supplies: (https://www.pegasusautoracing.com/group.asp?GroupID=COOLPUMP )
Pegasus also has various hose adapters that are helpful as the Davies Craig Pumps use 1 ½ inch hose for their input and output ports. I know many have used Electric Water Pumps to cool their engines, but this application was new to me, and I thought it may be helpful to others. I selected this engine cooling option because I liked the concept of using an Electric Water Pump and the Controller to regulate the water flow maintaining the correct cooling for the engine based the actual engine requirements. It also does not take any horsepower from the engine, and when an Electric Fan is used, it is much safer, and again, does not take horsepower from the engine.
After the engine had idled in traffic, the water temperature taken from the top hose, was 177° F when I shut the engine down the electric water pump and electric fan continued to operate. I monitored the temperature on the controller, and the temperature dropped about a degree every 3 seconds until the engine was cooled to a more reasonable level. I am very pleased with how the Davies Craig Water Pump and Controller is maintaining the engine temperature. I would recommend as this setup as a viable option when looking for a more modern cooling system.
Colorado 80550, United States
*A big Thank You to Bob for putting this together. We appreciate him sharing this information as its a terrific story and will help others considering the EWP conversion.