440 Water Pump Pulley/Crankshaft Pulley Sizing to Overdrive Water Pump

[MoparCarGuy]

I am looking at options to overdrive my 440 water pump. My existing pulley setup is the March Serpentine Kit 40550-8 in black powdercoat. This kit has been on my 440 for over 20 years. No cooling issues except in Florida. Go figure.
My idling temp creeps upwards to 210°F with a 195°F thermostat. I am using all factory cooling components except for a Speedmaster High Volume water pump. I had a Milodon water pump previously and had the same issue. It may be that Florida is just too hot and humid for the factory systems.

That being said, the crankshaft pulley diameter is 6" and so is the water pump pulley (fan pulley) which provides a 1:1 ratio.

The Factory Service Manual (FSM) shows a 1.4:1 crankshaft to fan ratio (see ☆ in FSM chart below) which would require changing one of the pulleys to get to 1.4:1 overdriven. My other factory components are in the green boxes. Usual stuff, shroud, 7-blade fan, etc.
Option: Keep the 6" crankshaft pulley and reduce the fan pulley to 4.25" to achieve 1.4:1 overdriven for the water pump.

The fan pulley drives the water pump AND the alternator so it may need to have a 6"/4.25" combo pulley to drive both pump & alternator correctly.
Does anyone know if March makes a 4.25" version of the dual, belt fan pulley?

 

[Challenger RTA]

Just a thought. Turn on the heater. been there done that it got me home.

 

[Challenger RTA]

An other thought: Don't go to Florida.

 

[Challenger RTA]

No really I know you are a knowledgeable member. Sometimes simple is better. Here are my thoughts and questions on that. I not saying it right It's just a though. I know your looking for a fix not a thought. There is the racers edge and then there is durability. The same as a stuck open thermostat the water doesn't stay in the radiator long enough to cool down. Is an aluminum or brass radiator better and for how long. Having a high flow pump or speeding it up, it might not be cooling down as needed. Maybe try a stock pump or you already had one in and it didn't cool as needed. The things that also come to mind. Coolant mix, engine cooling jacket flushed, radiator condition,pulley size,fan and shroud. The the fuel octane compression and AF ratio. If you Chrysler didn't design it you out side the realm of practicality. Next step look at the Gen 3 Hemi design improvements and maybe apply.

 

[Xcudame]

Does it only creep to 210°F in heavy traffic? The cools back down on open roads? 210°F isn't that bad stuck in traffic in high temperature and humidity environments. The pressurized coolant system can easily go to 250°F without boiling the water. If it keeps creeping and doesn't cool back down with lots of air flow, then you have an issue.

Chrysler had (still has) some of the best cooling systems. The best setup is to duplicate what the Mopar cop cars had. I used to drive my 70 Challenger in roll/stop traffic for hours and I got a lot hotter than the car ever did!! I grew to despise traffic, that's why I live out in the desert with the nearest city of about 5000 people.

An interesting features of newer car gauges is they don't show swing in temperatures extremes like our old gauges do.

 

[Steve340]

210 in heavy traffic is OK. Does it get any higher?
What type of radiator and cooling fan??
I don't think speeding up the water pump will do much.

 

[Ricks72Chlgr440]

The aftermarket aluminum 2 core radiators are very efficient compared to the 3 and 4 core radiators our cars came with. You might want to consider going aftermarket. Another consideration is your idle timing. If the engine is timed too retarded at low RPM it will generate too much heat.

 

[MoparCarGuy]

More info to answer some of the questions everyone asked...
Factory style 26" Modine radiator with 16lb factory style radiator cap and 195°F thermostat, 7-blade factory fan 2863216 and shroud, and fan clutch (it works correctly). Both crankshaft and fan pulleys are 6" serpentine (1:1 ratio) by March Performance. Sanden R134a A/C kit from Classic Auto Air.
Radiator/block was recently flushed until water ran clear and then filled with 50/50 mix of Prestone antifreeze and a bottle of Water Wetter. I have considered going to a 90/10 mix to maximize the better heat transfer of water. It is Florida so it never reaches anywhere close to freezing anyway.

Absolutely no cooling issues in Missouri/Georgia. Florida heat and humidity is the culprit.
Engine is a 1999 500 CID Mopar Performance crate motor with Indy 440EZ aluminum heads and 11.15:1 compression ratio. Cam is .545/.545 lift with 241°/247° duration at 0.050.

Timing is 16° BTDC and controlled by Holley Terminator X Stealth fuel injection with Holley Hyperspark ignition and distributor. AFR is 13.25:1 at idle speed of 900 rpm, all controlled by the Terminator X fuel injection's Bosch 4.9 O² sensor.
The Coolant Temperature Sensor (CTS) for the Terminator X display is digital and the temperature reaches 210°F in slow-moving traffic and will creep up at a traffic light to 215°. Max temp I have ever seen was 219°F at a traffic light.

I also have two, supplemental Spal 9" electric pusher fans on the front of the A/C condenser. Each fan is approximately 600 CFM and has its own relay controlled by the Terminator X individually. Fan #1 ON 205, OFF 195. Fan #2 ON 210, OFF 195.
At speed the electric fans do not come on and coolant temp is 195°F.

I am not interested in going to an aftermarket aluminum radiator but I would consider a GlenRay 3-row max cooling 2998956 radiator to keep as stock-looking as possible. Almost every Mopar in my area has an aftermarket aluminum radiator with shroud and huge electric fans.
I am trying to not go that route.

 

[Ricks72Chlgr440]

More info to answer some of the questions everyone asked...
Factory style 26" Modine radiator with 16lb factory style radiator cap, 7-blade factory fan 2863216, and fan clutch (it works correctly). Both crankshaft and fan pulleys are 6" serpentine (1:1 ratio) by March Performance. Sanden R134a A/C kit from Classic Auto Air.
Radiator/block was recently flushed until water ran clear and then filled with 50/50 mix of Prestone antifreeze and a bottle of Water Wetter. I have considered going to a 90/10 mix to maximize the better heat transfer of water. It is Florida so it never reaches anywhere close to freezing anyway.

Absolutely no cooling issues in Missouri/Georgia. Florida heat and humidity is the culprit.
Engine is a 1999 500 CID Mopar Performance crate motor with Indy 440EZ aluminum heads and 11.15:1 compression ratio. Cam is .545/.545 lift with 241°/247° duration at 0.050.

Timing is 16° BTDC and controlled by Holley Terminator X Stealth fuel injection with Holley Hyperspark ignition and distributor. AFR is 13.25:1 at idle speed of 900 rpm, all controlled by the Terminator X fuel injection's Bosch 4.9 O² sensor.
The Coolant Temperature Sensor (CTS) for the Terminator X display is digital and the temperature reaches 210°F in slow-moving traffic and will creep up at a traffic light to 215°. Max temp I have ever seen was 219°F at a traffic light.

I also have two, supplemental Spal 9" electric pusher fans on the front of the A/C condenser. Each fan is approximately 600 CFM and has its own relay controlled by the Terminator X individually. Fan #1 ON 205, OFF 195. Fan #2 ON 210, OFF 195.
At speed the electric fans do not come on and coolant temp is 195°F.

I am not interested in going to an aftermarket aluminum radiator but I would consider a GlenRay 3-row max cooling 2998956 radiator to keep as stock-looking as possible. Almost every Mopar in my area has an aftermarket aluminum radiator with shroud and huge electric fans.
I am trying to not go that route.

You have likely reached the cooling limit of your current configuration. Since the temp comes down when you're moving, I would not be concerned about going to 220* in traffic with the A/C on. The aftermarket A/C condensers generally mount right up against the radiator (where the OE style had a nice gap between the condenser and the radiator), thus pre-heating all of the incoming air while the A/C is on. The condenser also inhibits airflow so at low speeds you're not getting a lot of flow. As for the idea of 90/10 antifreeze mix: don't do it. The evaporator is right next to the heater core under your dash. When you use the A/C, the evap can freeze, and without the proper mix of antifreeze can damage your heater core.

 

[Challenger RTA]

I'm not all that familiar with that system. Just a thought. The control systems are the parameters set to change for elevation or altitude?

 

[Xcudame]

I agree with Rick, I think you're OK and keep the 50/50 mix. Try not to look at the temperature gauge in Florida.

Also, with that engine combo, you're generating a lot of horsepower and heat! It must be fun to drive!

 

[Ricks72Chlgr440]

I agree with Rick, I think you're OK and keep the 50/50 mix. Try not to look at the temperature gauge in Florida.

Also, with that engine combo, you're generating a lot of horsepower and heat! It must be fun to drive!

I live in South Texas and drove my 440 Challenger back from the alignment shop. There was road construction so we were down to one lane so had to wait in line for our turn (was about 10 minutes of standing still, idling). My engine got to about 220, and came down to about 190 after we got going again. Though we don't like running it hot like that, it's just not a big deal to occasionally do so.

 

[Xcudame]

Remember, 250°F is the boiling point for plain water with a 16 psi cap. You get a wee more with the coolant and water wetter!

 

[MoparCarGuy]

I'm not all that familiar with that system. Just a thought. The control systems are the parameters set to change for elevation or altitude?

Yes, the Holley EFI systems adjust fuel delivery to match the elevation by maintaining the AFR via the oxygen sensor.
You can adjust the fuel parameters to limit the +/- percentage of allowable change.

 

[MoparCarGuy]

I had not considered the A/C evaporator being in close proximity to the heater core if using a 90% water/10% antifreeze mix.

I had thought about draining the heater core “loop” and permanently isolating it at the heater control valve. I would keep the hoses to appear stock. Draining the heater core loop would prevent a heater core freeze up from a malfunctioning A/C system where the evaporator coil temp went below the typical 40°F coil temp.
I would like to cap the water pump’s heater hose inlet and outlet and mock up the hoses but have not figured a way to do that.

Not related to the engine temps but obviously there is no heat needed in FL.

 

[Ricks72Chlgr440]

I had not considered the A/C evaporator being in close proximity to the heater core if using a 90% water/10% antifreeze mix.

I had thought about draining the heater core “loop” and permanently isolating it at the heater control valve. I would keep the hoses to appear stock. Draining the heater core loop would prevent a heater core freeze up from a malfunctioning A/C system where the evaporator coil temp went below the typical 40°F coil temp.
I would like to cap the water pump’s heater hose inlet and outlet and mock up the hoses but have not figured a way to do that.

Not related to the engine temps but obviously there is no heat needed in FL.

I use the Vintage Air setup and they specifically say to use a 50/50 mix for that reason. I live in South Texas and "normally" don't need a heater..... but on those cold days (we do get some)... it sure feels good!!!

 

[Steve340]

I would not disconnect the heater core. Often overlooked is due to the way the heater core is hooked up it functions as a way for the cooling system to bleed all the air out of the engine.
When I was an apprentice I was taught to open the heater valve when I refilled a cooling system.

If you are only interested in the anti corrosive function it is suggested to not drop below 30% antifreeze and 70% water. Water is better able to transfer heat than antifreeze.

 

[MoparCarGuy]

70/30 is a better option then.

 

[Steve340]

You have a nice setup on that car. Based on what you wrote in your earlier post in my opinion I don't see that you have anything to be overly concerned about.

 

[moparleo]

Exactly. And have you actually tested the coolant temp before and after the thermostat ?
Are you relying on your dash gauge for the temperature reading ?
Did you test your radiator cap. They go bad quite often and are seldom even considered.
16 lb cap raises the boiling point considerably.
Modern cars run over 200° all the time on purpose to help lower emissions.