Electric Water Pump - worth it?

[BigMuz]

A clutch fan and a mechanical pump will cater for sitting still in traffic better than any other system.

The ONLY advantage I can see is a tick tock setup like heaps of drag racers use. The water pump cycles for only a few seconds, then the fan runs and cools a radiator full of water, then the pump cycles again. That is a quick and efficient way of cooling an engine IN THE PITS WITH THE ENGINE SWITCHED OFF.

Anyways, tomato tomato.

[10sec rx7]

i use them in the rotors and dont have a problem, the one on 13bee is a series 2 one and it is over 2 years old with no problems what so ever,

best bit is on the dyno switch off engine run water pump with over ride switch, temp drops from 90 down to 70 in under 1min

[bazeng]

jmac - no, just one probe, deep in the thermostat housing with the stock thermostat removed, so as close to the head as possible... we've checked temps around that area and it seems accurate (using one of the laser temp probes)...

its also a bonus with no water pump pulley to get in the way.. 1 belt only, the alternator... its a real pain in the ass with these fwd mounted engines to access the tbelt / belt area...

the only other issue i can think of is mounting the pump...
if its mounted on the chassis, the movement of the motor could possible damage the pump (plastic), if mounted on the engine, it would also do the same unless due to the fixed position of the radiator...
the only possible fix would be to have long radiator hoses or like what i have done.. have the water pump supported by nothing bar the radiator hoses...

how have u guys mounted the water pump?

[10sec rx7]

its mounted off the chassis with -20 adaptors and -20 hoses

[Jim]

here's a thought: why not a clutch on the water pump to give it a maximum RPM not in proportion to engine RPM? It would solve a lot of the power drain issues, and also prevent high RPM cavitation. And potentially be a fuckload simpler and more reliable.

[XEFalconUte]

You may find the -20 hoses more of a restriction than the thermostat itself.

When I was designing the cooling system for the big block I measured the maximum open area of the thermostat (I'm using SBC type) and the cross sectional area of -20 hose was less than the are provided by the thermostat. I know a straight hose will flow slightly more than the same area in a thermostat but its close enough for my purposes. I'm using -24 hoses and 1 1/4 NPT threads everywhere.

Might also be an idea not to use 90 degree bends and use 45's and more hose?

Just my 2 cents.

Have fun

Simon

[10sec rx7]

we dont have any over heating issues, even in the middle of summer,

and that is with a 13b bridge port, GT45, c4 auto, the temp never raises over 92deg in normal driving, in traffic it will go to around 96 which is pretty normal for a rotor,