Smaller diameter water pump pulley

[Mark1972]

I'm currently running the single groove unit from 440Source I put on the car years ago.

Water Pump Pulley - Non A/C - New Reproduction

I've been fighting overheating issues, at idle, for years. I've tried different stats. Currently running a 195 Robertshaw. I know airflow is the problem as when I'm parked at idle, and it start keeping towards 210, I just put it in neutral and rev it to around 1500rpm, and it comes back down to 200-205. I've also been told my timing could be causing issues as well. Im still doing more research on that. It's been recommended that I try overdriving my fan to increase air flow. The 440Source pulley is 6 13/16" diameter x 2 11/16" depth. Apparently the A/C pulleys are smaller, but I cant find one with a single groove. Can anyone point me in the right direction?

 

[toolmanmike]

210 with a 195 stat isn't overheating. What radiator/fan/shroud are you running? Have you pressure tested your cap? Coolant doesn't boil until about 245° with a 15# cap.

 

[Mark1972]

Running a Cold Case 26" rad, 16psi cap, a 19" 6 blade fixed Derale fan with 4" wide fins, and a shroud with a 20.5" opening. The cap is new, but I haven't checked to see if its working.

 

[toolmanmike]

Running a Cold Case 26" rad, 16psi cap, a 19" 6 blade fixed Derale fan with 4" wide fins, and a shroud with a 20.5" opening. The cap is new, but I haven't checked to see if its working.

That sounds good. If it were me, I would switch to a 180° stat and see what happens. That 15° cushion may be what you need.

 

[Mark1972]

That sounds good. If it were me, I would switch to a 180° stat and see what happens. That 15° cushion may be what you need.

I've been running a 180 and just switched this year to a 195 to see if it would help, lol. With the 180, it would certainly run the 10-15 degrees cooler while moving, but then creep into the 210-220 range at idle, especially coming off the highway where it was at 3100rpm(60mph)for a while. Then it sure didn't take long at idle for temps to jump. It happened to me last night. Came off the highway and to a dead stop in construction. 210 in about 3 minutes. So I revved it up to 1500rpm and it came back down to 200-205. So airflow definitely helps. That's why I'm thinking about a pulley change. I also might use it as an excuse for that new fiberglass a12 hood the wife doesn't think I need. Don't tell her.

 

[pnora]

It sounds to me like your fan and shroud are not doing their job.

 

[toolmanmike]

It sounds to me like your fan and shroud are not doing their job.

Agreed. The fans that are attached to the clutch are large enough, have enough pitch, and amount of blades to move a serious amount of air, especially with a shroud. And engine at idle under no load, doesn't produce much heat.
Clutches at 210° or so should be pretty much locked up. The clutch should begin to lock up at 180-190° coolant temp.

When the engine get's hot, shut it off and see how locked up the fan clutch is. You may need a new clutch. Make sure the blade is on correctly. (you never know)

 

[Don67Satellite]

Are the fan blades positioned correctly in the shroud? Like 50% in, 50% out roughly? Gotta make sure its actually pulling air through the radiator, if they aren't the flow will be hampered and you'll just be throwing hot air around in the engine compartment.

 

[HemiLane]

I had an overheating issue at idle with mine. When I got the car, it had aftermarket AC, no idler puller, larger WP pulley, and the WP belt ran to the PS. I noticed that the flow through the radiator was slow. I went to the smaller AC WP pulley and added all the proper AC car brackets, idler puller, and 4 groove crank pulley. No more overheating issues in AZ! Also, installed the proper shroud and fan. Post on the forum for WTB AC WP pulley or check ebay, they should be out there, a lot of conversions from AC to non-AC out there.

 

[Mark1972]

Agreed. The fans that are attached to the clutch are large enough, have enough pitch, and amount of blades to move a serious amount of air, especially with a shroud. And engine at idle under no load, doesn't produce much heat.
Clutches at 210° or so should be pretty much locked up. The clutch should begin to lock up at 180-190° coolant temp.

When the engine get's hot, shut it off and see how locked up the fan clutch is. You may need a new clutch. Make sure the blade is on correctly. (you never know)

It's a fixed fan. I have a clutch for it, but removed it as part of trying to figure out this heating issue. The fan is installed correctly.

 

[Mark1972]

Are the fan blades positioned correctly in the shroud? Like 50% in, 50% out roughly? Gotta make sure its actually pulling air through the radiator, if they aren't the flow will be hampered and you'll just be throwing hot air around in the engine compartment.

Yes. It took a while with different spacers but I achieved the 50/50.

 

[Don67Satellite]

CVF Racing carries big block water pump pulleys.

They have a 6.9" & 6.2", can be had in black or polished in single groove.

 

[toolmanmike]

It's a fixed fan. I have a clutch for it, but removed it as part of trying to figure out this heating issue. The fan is installed correctly.

Wow, We are getting nowhere fast. How much larger is the water pump pulley than the stock one?

 

[Don67Satellite]

I replaced nearly everything to fight the cooling issues I had.

You may also consider a higher flow water pump. I installed a Flowkooler.

It wasn't the magic bullet, but it did contribute a lot to the solution.

 

[toolmanmike]

Yes. It took a while with different spacers but I achieved the 50/50.

You did mention your tune. What is your combination and timing look like? I hope you're not going to say you have a +.060 12.5/1 engine with a .700 lift roller. LOL

 

[Cranky]

Agreed. The fans that are attached to the clutch are large enough, have enough pitch, and amount of blades to move a serious amount of air, especially with a shroud. And engine at idle under no load, doesn't produce much heat.
Clutches at 210° or so should be pretty much locked up. The clutch should begin to lock up at 180-190° coolant temp.

When the engine get's hot, shut it off and see how locked up the fan clutch is. You may need a new clutch. Make sure the blade is on correctly. (you never know)

Bought a car once that was having overheating issues and found the fan was on backwards lol. Fixed it and the issues were gone.

 

[Mark1972]

You did mention your tune. What is your combination and timing look like? I hope you're not going to say you have a +.060 12.5/1 engine with a .700 lift roller. LOL

1977 440 bored .030"
Align bored
Decked
Factory cast-iron crank ground .010" under
New SCAT H-beam rods
Keith Black pistons(10-1)
Eddy RPM intake
Eddy E-Street heads (75cc chamber's)
Engine balanced
Doug's headers
CompCams XE268H cam and lifters
Melling M63 HV oil pump and pick up
Carter M6903 fuel pump
Proform Mopar electronic distributor
MSD wires
440Source 6 quart oil pan, windage tray
35 degrees total
12 degrees initial
No vacuum advance(plugged)

 

[Geoff 2]

Yes, a smaller pump pulley will help. So will more initial timing, about 20*.
More here: www.stewartcomponents.com

 

[BMosely]

We fought some of this on the ‘68 Coronet. I agree that the 210* is not overheating but these big blocks on today’s gas get really unhappy trying to idle with that heat creep. In Atlanta so stop and go traffic is not avoidable or you would never get to drive. I chased it all and the correct fix for me was getting the right electric pusher fans to take over while the big cam loping around at idle has the clutch fan essentially doing nothing. I ended up with (2) Spal 10” pushers at I think 1450 cfm each. It moves some air now and fixed the heat creep and as an added bonus I think it pulled the ac temperature down a few degrees as the fans are mounted on the condenser.

A few notes. Not all electric fans are created equal. Some rate the cfm unloaded with no static pressure and some (Spal) have available pressure charts for each fan to see the actual cfm production with static resistance which is what happens in the real world with a radiator and condenser in the way. The usable cfm drops off incredibly fast with resistance. So, to save everyone some time, get a Spal in the size you need.
Controllers. My experience with Derale is poor to poor. I went thru 3 over a year or so with each failing in different fashion. These were the units that mount underhood which I always suspected was not the best design or mounting option. Luckily, on the car build we installed the Dakota Digital dash and they now make a compatible fan controller that integrates into the dash computer. It mounts inside and has been flawless and the best part is that it is Bluetooth and tuneable. I have it set to run 100% ac on and then on at 195* and off at 185*. Even better since I run a carb, if the fan is running at shutdown, I have it set for a 3 minute shutdown delay which helps kick that heat soak out during the heat of summer when running errands and you will be back in a few minutes restarting. Today’s gas does not like being unpressurized in summer heat. Fuel injection does not see this due to the pressurized system.

 

[BMosely]

Old fans before upgrade. These were Summit branded and just did not push any air.
Spal model used.