Electric water pump otions, looking for opinions

Julian West · 01-11-05, 10:58 AM

Am in the final process of sorting my engine spec & am stuck on wether or not to go for an electric water pump.

From my research so far, it looks as if there are three options,

1. fit an 'inline' pump near the radiator & modify the existing pump by removing the impeller & fitting a blanking plate.

2. fit an engine mounted water pump like this one - http://store.summitracing.com/default.as...r+pump+electric

3. just stick to the 'old' belt driven pump.

Option 3 is cheapest, but i believe there are advantages to 'going electric'

Does anyone have any opinions over options 1 & 2 ??

Thanks in advance!

Fred/Belgium · 01-12-05, 03:12 AM

Julian,

Long debate on subject with my mecanic.We choose for HV mecanic aluminium option (mainly road usage but tracktime sometimes).
Fred

RobBrom · 01-12-05, 05:20 AM

I've gone for option 1.The main advatages are:
a) No horsepower is lost by driving the pump;
b) You can control the pump according to the engine needs;
c) It can be used to continue cooling the engine after the ignition has been switched off (a good idea IMHO for these cars);
d) The access panel behind the seat can be made flat so the pump doesn't intrude into the cabin. I'm using a 351C and the pump was so long that the intrusion into the cabin could be used as an armrest!

It may be an idea to weld a diverter into the cover plate so that the incoming water is diverted into the block rather than across the face of it. I've just done this mod but I'll have to wait until warmer days to see if there's any difference.

Hope this helps.

Andy Besic · 01-12-05, 07:44 AM

Is the static flow of an electric pump a disadvantage for a road-race type of engine? Correct me if I'm wrong, but won't an electric pump move the same amount of coolant at 800rpm as at 7000rpm? It seems to me that a 30 to 60 minute track session would need a belt driven, variable pump, or does the electric pump flow as much as a belt driven at it's peak flow?

Andy Besic
Floating in the same boat as Julian.

RobBrom · 01-12-05, 10:54 AM

I need all the cooling I can get so my pump's on all the time and is set to continue after turning off the ignition until the coolant temperature falls below 80 deg C

For more info see

www.daviescraig.com.au

http://www.hovercraft.org.uk/forums/...es/11148.shtml

Brett James-McCall · 01-12-05, 11:06 AM

Can't you adjust flow with the DC pump if you buy the controller?

Also, as a question, I had heard some people had problems with the seals, as older engines sometimes gave off 'debris'. Any comments?

Brett

DaveWharran · 01-12-05, 10:53 PM

I've ran a Davis Craig electric pump and speed controller since putting the car on the road 13,000 miles ago. No mechanical pump at all. No mechanical thermostat.
The voltage suplied to the pump varies based on coolant temperature as read by a thermister installed where the thermostat used to be.

BEWARE of the warm-up curve the Davis Craig controller supplies. It pulses the pump on and off as the engine warms up....off a lot longer than on.
The "curve" it supplies is probably okay for a front engined car, but in a mid engined car, at least mine, the distance from the engine to the radiator causes the radiator to be temperature shocked causing the tubes to crack from the tank. Ron Davis commented that the aluminum radiator can not stand the rapid differential temperature.
I had 2 radiators crack before discovering what what was going on.
The short term fix is to not let the pump cycle on and off during warm up. I keep a constant 3 volts on the pump at all times and let the DC controller ramp it up from there as needed by cooling demand. Warm up times are increased, but I haven't cracked a radiator since allowing it to warm up along with the engine. I am currently working on an upgraded program for the DC controller to better suit my car. Davies Craig did not respond to emails asking for a microcontroller program change for mid engine cars.

Bob Putnam from ERA has had a DC pump running in a car for a good while with no problems. I'm not sure what is different in their setup from mine.

I did have a pump lock up one time while idling in front of the house. Clearances in the pump are close and if allowed to get too hot, it seems like the pump impeller wants to weld itself to the pump housing. I understand DC is making design changes in the area of the seal. This doesn't address the pump impeller problem I had. I've heard of one other person in addition to me that had an impeller lock up
I've had no seal problems.

Plumbing for the Cleveland in the ERA chassis would have been difficult if not impossible using a mechanical pump. The electric pump fit well and works well taking into account the warm up/controller issues and the impeller welding issue.
I believe in the electric pump and feel it can do as well or better than a mechanical pump. It can speed up to max rpm regardless of engine rpm, a benefit going through town in a high gear at low speed.

The controller uses a Microchip PIC controller doing PWM voltage control. It switches the neutral that attaches to the pump NOT the positive voltage.

I believe Davies Craig had cars running their pumps at Le Mans last year. Dual pumps on the car.

Dave

Kalun D · 01-13-05, 01:58 PM

Just went through this decision process.

Electric (remote)

More room in the most crowded area of the car.
Controls flow better
Gains 10 to 20 HP
More wiring
More plumbing
More expensive ($320.00)
Same weight

Mechanical

Simpler plumbing
Less expensive
Less room
Poor flow control
HP loss

www.Meziere.com says controllers are not even necessary, the electric pump has better flow dynamics overall than mechanical without any flow control. Pretty convincing when an expert gives advice that potentially means he's going to sell less product. Think about it, a mech pump runs too slow at idle and too fast at red line. If you run underdrive pulleys for high rpm driving then it's going to overheat in traffic. The pump is wired direct with key on to make it more fail-safe.

I think the HP gains might be exaggerated when they say 30 HP because you have to figure you're loading the alternator at least a little. Maybe their talking about at 8 grand on a race motor.

Mounted inline near the engine with 1-3/4" hose inlet and 2 -12 lines to the engine. Bagged the expensive and bulky adapter plate at the engine and went with two small 3 hole alum plates with 3/4" NPT holes for the -12 lines. Really simple to make. I even cut down the water pump face of the front cover.

The only thing I don't like about the DC is it's nylon, the Meziere is all aluminum including the impeller.

Tim Kay · 01-13-05, 02:08 PM

Kalun,

Nice review, just the info I was interested to hear, I'm sold [img]/ubbthreads/images/graemlins/wink.gif[/img]

You wouldn't happen to have a pic of your install as decribed?

Tim Kay · 01-13-05, 02:25 PM

Kalun,

[ QUOTE ]
I even cut down the water pump face of the front cover.

[/ QUOTE ]
does that mean the bulkhead cover in the cabin was reduced down so it doesn't protrude in as much between the seats?

also, was there a reason to mount the pump close to the engine rather than in front, close to the radiator?

Kalun D · 01-13-05, 03:02 PM

Haven't finished the install yet, the pump will be on the left side of the engine down on the floor pan.

5/16" (8mm) 7075 T7 plate, go with 3/8" for 6061

Start

Kalun D · 01-13-05, 03:03 PM

Mark, drill, tap, cut, grind, file, sand.

Kalun D · 01-13-05, 03:06 PM

HACK, grind, file, sand, bead blast(not done yet in these pics)

Kalun D · 01-13-05, 03:08 PM

Almost done. What's lighter, a water pump with the front cut off and plugged or 2 little plates with part of the front cover gone.

"does that mean the bulkhead cover in the cabin was reduced down so it doesn't protrude in as much between the seats?"

about 4" - 5" more clearance than the mech Ford short water pump, the firewall can be flat now, no bulge.

"also, was there a reason to mount the pump close to the engine rather than in front, close to the radiator?"

The plumbing was simpler with this model pump because it has 2 outlets which go directly to 2 engine inlets. Meziere makes a 1 inlet 1 outlet pump which you could put in front but it costs more.

Tim Kay · 01-13-05, 04:27 PM

Thanks Kalun, I am going the same route. Thanks for head start [img]/ubbthreads/images/graemlins/smile.gif[/img]

JimmyMac · 01-14-05, 11:18 AM

Kalun,
I am using the very same Mezier pump as you have described.
The front of my block is now very neat by fitting a custom made one piece timing cover made by Mike Garrett.
Here is a flic.

JimmyMac · 01-14-05, 11:20 AM

Kalun,
And another of the inside of the plate.

Hershal Byrd · 01-15-05, 12:04 PM

I just thought I would chime in hear and let you guys know that there are those of us out here that have the mechanical systems that work. My water pump is the standard Ford issue for a 302. I'm going on three years now without any overheating issues. I live in the Desert too.
A properly designed cooling system will work. Other than the space fittment problem I see no reason to use an electric pump. Horsepower loss is minimum. Electric pumps are not cheap either.
Dave, I use a laser temp gun to check the variance from and to my radiator. There should be 7 to 10 degrees variance between the in and the out of the radiator. If it's less, then you have restriction problems or timing problems.
I really thought it would be interesting to see who uses electric over mechanical so I made a Poll.

Hersh [img]/ubbthreads/images/graemlins/smile.gif[/img]