Do the high flow water pumps really work?? Could be a lotof work for nothing.
hmm... there are several reasons for HIGH flow water pumps...and this gets complicated.. so please hang with me.. coolant flow comes out of the pump into the block.. around the cylinders.. up thru the back of the heads... forward thru the heads and into the crossover passage where the thermostat blocks the flow. there is in all cooling systems a coolant bypass circuit.. where this coolant that is blocked by the closed thermostat is allowed to get back into the water pump to be circulated again.. the bypass allows the coolant to go round and round thru the block and heads until it picks up enough heat to cycle the thermostat open.. at this point.. the hot coolant flows into the radiator displacing the cooler coolant there... that cooler coolant makes the trip thru the block and heads and as it passes the thermostat.. it closes it.. this allows the coolant in the engine to slowly pick up heat again.. while the coolant in the radiator is stopped and its loosing heat to the air thru the radiator .. either by ram air.. or by the fans pulling/pushing it thru.without a thermostat. the coolant takes forever to get warm.. and under some situations can circulate thru the radiator faster than the tubes can flow and the pressure in the upper tank builds until it causes the tank to bulge and blow the solder joint or gasket.. with a thermostat.. because the bypass is smaller than the flow the water pump can put out. there is actual mechanical pressure built up behind the thermostat. this allows the hot coolant to flow the long way thru the heater hoses and core.. the increase of mechanical pressure actually is a good thing.. as it prevents the HOT SPOTS in the cooling system around the exhaust ports and exhaust valve seats from boiling the coolant.. yes.. under high RPM loads the exhaust area in the heads can get over 265F which is the boiling point of a 50/50 to 70/30 mix at 15 psi.. sidebar... nascar and other circle track cars use straight water in their cooling systems.. they are what the high flow pumps are made for.. because nascar racers do not run thermostats only restrictors.. they need to build as much mechanical pressure in the block behind the restrictor as possible to keep the water from boiling away from the hot spots in the heads.. i don't know if they still have this issue.. but you may have heard that they have to use a new radiator each race.. something about them getting so clogged with dirt from the track that air won't pass thru and it won't wash out.. what actually happened is the oval aluminum tubes have been exposed to so much system pressure and mechanical pressure because of the massive amount of flow.. that the oval tubes try to go ROUND.. crushing the fins between them and blocking the airflow completely sometimes.. i am not a circle track racer.. i would if i were want to measure the mechanical cooling system pressure around a dyno mule with used heads that have additional ports for pressure gauges... i would want to look at the metal temps.. perhaps with some creative probes drilled into the aluminum also.. moderating water pump speed at expected race speeds to keep the temps below ... and the load on the engine at an optimal point.. i have been thinking about a water outlet for dyno runs and track testing.. that has an adjustable tapered plug.. so i could change the amount of flow going thru the restrictor.. but thats just me .. so.. do you need a HIGH FLOW water pump????perhaps.. are they good looking? YEP... will they last a LONG time.. probably.. i have had an idea that i will probably never get around to making.. perhaps somebody will read this and get some made..look at a 3.1L chevy from a front wheel drive transverse application where the water pump is out infront of the head.. i want to build a pump on the left and a different one for pump on the right. versions of just the crossover.. that allows the use of the bolt on 3.1 chevy pump. this would give the user the ability to really make more room in the front of the engine for rod installs.. more later..