So I hear a lot of talk about how to remove the heat increased by all the horsepower parts sold here.

Some vendors swear by blankets, DFICs, bigger scoops, even now added scoops on the hoods.

So I have one possibly stupid question:

What happends to the factory water pump/water circulation with a let's say 17 or 19% pulley, or increased redline.

I am sure the factory uses the same water pump driven by the supercharger for both regular S, JCW and GP.

Should some of you consider going to an electric water pump?

Any thoughts or comments

Victor

 

<< What happends to the factory water pump/water circulation with a let's say 17 or 19% pulley, or increased redline. >>

Coolant flow goes up, with several possible results. I don't know the MCS specific results, but the general ideas come from water pump / cooling system testing at work on other engines which were very heavily instrumented.

1. Increased coolant flow can increase heat transfer from engine components, thus reducing metal temperatures.
2. Reducing combustion chamber metal temperatures can increase component life, if the temperatures were previously marginal for the material.
3. Increased coolant velocity can acclerate errosion issues with aluminum components, again if the coolant velocities and design of coolant passages in aluminum components were marginal.
4. Decreased life of the water pump seals, relative to another engine with IDENTICAL duty cycle but slower water pump rpm relative to engine rpm. Other factors also impact water pump seal life, so this is no guarantee that MINI owners will or will not have problems.
5. The water pump can cavitate, which is bad. Cavitation can dramatically decrease coolant flow, thus dramtically increaseing metal temperatures throughout the cooling system. Cavitation is dependant upon cooling system pressure going into the water pump (altitude and pressure cap function can effect this, along with how recently you opened the coolant cap and thus bled off the pressure that had been built up). Cavitation limits are also dependant on coolant temperature and the design of the cooling system.
6. Increased water pump rpm increases cooling system pressures. Along with the comments above, increased pressures can create leaks at cooling system joints. Again, this assumes those joints were already marginal.
7. Increased water pump rpm increases parasitic losses. The water pump isn't typically a major source of parasitic power consumption, certainly nothing even remotely close to the supercharger on our engines.

Two last points.

First, I've got a 19% pulley on my own car and have since the middle of 2004. Prior to that I had a 15% from December 2003. I've got over 110,000 miles on the car, with one of the two pullies just mentioned for 80,000 miles. No cooling system issues at all. I don't spend much time above 4000rpm, with the exception of autocrossing. In general, my car sees a very easy duty cycle. My rev limiter is at 7325rpm, fyi.

Second, and this applies to all cars. If you are in heavy traffic and your car is overheating, you can try putting it in neutral and reving the engine up to about 2000-3000rpm. The increased coolant flow, combined with the light engine load, will reduce the coolant temperature. This might buy you a little more time to either get the car shut off in a safe place or get moving again so you have some airflow across the radiator.

Scott
90SM

 

Isn't that approaching it sort of like a colder thermostat?

 

Thanks Scott

 

19% pulley here and yes, when I have the money, I will most def switch to electric water pump. But like 90sm said im not to worried about it right now. 45k.

 

90STX,
it's nice to see you covered all aspects of this. I was curious to see if you included cavitation and you do. What is especially cool is that you reported you have >100K miles on an auto that has a 19% pulley. That's saying something.

 

What do you mean? A colder themostat merely changes when the thermostat will start to open and circulate coolant through the radiator instead of just running it through the internal engine bypass.

Scott
90SM