Spinning the water pump faster?

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superchargeddrt

superchargeddrt

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Okay guys,

I've been trying to find this out for a long time. My car will run at about 180 degrees when moving but when I get stuck in traffic on a hot day I just can't keep it cool. I've got every cooling device known to man kind. High flow water pump, seven blade steel fan, aluminum radiator with shroud, electric pusher fan, engine oil cooler/transmission cooler combo and I've sealed the fiberglass hood to the rad support (which made a difference). The only thing else that think of to do is to spin the pump faster but try as I might I just cant figure out what the sizes are of the non A/C alternator and crank pulleys are versus the A/C pulleys. I think that someone might make a aftermarket pulley for increased flow but I'm not sure. Have any of you guys tried spinning the pump faster and did it work for you?

Thanks For Your Help!
 
Normally if it cools fine at speed but gets hot at a stop it is airflow. Take some pics of the radiator mounting and over all cooling system including the under side of the hood.


You don't even need a fan over about 35-40ish mph.

My bet is that you are pulling hot engine air back around and through your radiator.
 
you dont want to move the water too fast, or it wont spend enough time in the radiator. try a normal water pump. whats the condition of the engine? is it recently rebuild, maybe its old and water passages are clogged up and rusty?
 
you might want to find a factory AC water pump pulley, should be smaller dia. than a non air car

I bought a flow cooler water pump from summit, but have not gotten it installed. It is suppose to flow 30-40% more at idle but the same at speed

hope it helps mine, by the way it does the same as yours, ok at speed starts to creep up at idle
 
I was having an issue with pulling hot air back through the radiator. I am running a fiberglass hood and there was no seal from the hood to the rad support. When I added a piece of foam rubber to the undersid of my hood there was a significant improvement but it's still running too hot when in traffic. The engine was rebuilt back in 1988 and I have been maintaining the cooling system since. It's been flushed out on more than one occasion. This is why I'm thinking about changing the diameter of my water pump pulley to a smaller aftermarket type or if the A/C factory pulley was smaller then I would give that a try. Also I might try a clutch fan but I have to find one that will clear the belt for the supercharger.

Thanks for the input guys!

1968FormulaS340 said:
Normally if it cools fine at speed but gets hot at a stop it is airflow. Take some pics of the radiator mounting and over all cooling system including the under side of the hood.


You don't even need a fan over about 35-40ish mph.

My bet is that you are pulling hot engine air back around and through your radiator.
Click to expand...
 
If you had improvement with restricting hot air from getting to the front of the radiator I would look to see if you can do more in this area.

Block off all the holes in the core support leaving just enough open to allow wires to pass through. You can do this with duct tape when testing.

Some after-market radiators leave a big gap between themselves and the core support. If yours has this gap, it can be nicely filled with adhesive foam tape (found at RV supply stores).

How is the fit of the fan to shroud? Blades should be just inside the shroud and the fan diameter should be close to the diameter of the shroud opening.

Fan pitch could also be working against you. If you have a cheesy flex fan or one of those small bladed, plastic ones you may not be moving the air needed.


I really think getting all the hot air away from the front of the radiator and getting more air moving will solve your problem. I think this because...... When you get the car going and air is being naturally bushed in, your problems go away.
 
Fan put on backward ? just a wild guess. Good luck
 
I think you may be right 1968FormulaS340,

I found out about the hot air recirculation when I put the second aluminum radiator in my car. It was sitting in the driveway with the hood off and not goining above 170. I thought that the first aluminum radiator that I put in was bad and that this new on had cured my problem. Well I left the car running and put the hood on and went upstairs to wash my hands by the time I got back down to the car it was at 200 degrees. That's when I started playing around sealing the hood to the rad support. As I said it mad an improvement but still manages to creep up in traffic. I was thinking along the lines of what you were thinking. The aftermarket rad is a universal 26" and it does have a gap between itself and the rad support. I'm gonna get a roll of foam tape and seal it to the support and additionally I will also try to seal off the holes where the wires come through temporarily with duct tape and see what happens. Also I wanted to get your opinion on this. My hood scoop is there mearly to allow for clearance for the blower/carb and it is not sealed to air box for the carb. Do you think that this could also be an issue? I can't remember if I had this problem with the stock power bulge hood but I'm thinking I didn't.

THANKS to all of you for your valuable imput. I have been putting up with this for several years and I've finally decided that I'm gonna find the problem.

1968FormulaS340 said:
If you had improvement with restricting hot air from getting to the front of the radiator I would look to see if you can do more in this area.

Block off all the holes in the core support leaving just enough open to allow wires to pass through. You can do this with duct tape when testing.

Some after-market radiators leave a big gap between themselves and the core support. If yours has this gap, it can be nicely filled with adhesive foam tape (found at RV supply stores).

How is the fit of the fan to shroud? Blades should be just inside the shroud and the fan diameter should be close to the diameter of the shroud opening.

Fan pitch could also be working against you. If you have a cheesy flex fan or one of those small bladed, plastic ones you may not be moving the air needed.


I really think getting all the hot air away from the front of the radiator and getting more air moving will solve your problem. I think this because...... When you get the car going and air is being naturally bushed in, your problems go away.
Click to expand...
 
Have you blocked the holes between the front valance and K frame area? This will also force more air through the radiator. All newer cars have all that area blocked off to help force all the air through the radiator they can get.
 
I had good luck speeding up the water pump. March pulley's has what you need. You might have to shim the water pump pulley from behind. I modified some Chevy spacers
 
I assume you already checked that you aren't running lean at idle. That can generate more heat. Also, engines with a wild cam can be very inefficient at low speeds, which could increase heat losses. The stange thing is that you still have the problem with electic fans. That should be the same as driving at ~30 mph. Blocking the air gaps sounds like a good approach.
 
StrokerScamp said:
Have you blocked the holes between the front valance and K frame area? This will also force more air through the radiator. All newer cars have all that area blocked off to help force all the air through the radiator they can get.
Click to expand...

No I haven't but that might be a good approach as well. Thanks for the idea!
 
X2 on the lean idle. also a lean running carb or vac leak may also heat up your ride at low speeds.
 
dodge freak said:
I had good luck speeding up the water pump. March pulley's has what you need. You might have to shim the water pump pulley from behind. I modified some Chevy spacers
Click to expand...


Thanks Dodge Freak,

I am leaning towards getting a smaller (so it spins faster) water pump pulley. I see that March has what they call "High Flow" pulleys. Were you not able to get a pulley for a small block Mopar or did you just need to use Chevy spacers behind a pulley that was made for a small block Mopar?
 
BillGrissom said:
I assume you already checked that you aren't running lean at idle. That can generate more heat. Also, engines with a wild cam can be very inefficient at low speeds, which could increase heat losses. The stange thing is that you still have the problem with electic fans. That should be the same as driving at ~30 mph. Blocking the air gaps sounds like a good approach.
Click to expand...

Yeah it's definately not running lean at idle. If any thing it's running a little fat. You can't stand behind it for too long or it will bring tears to your eyes. I set the idle up with a vacuum gauge for maximum vacuum and I set the timing at 10 degrees advanced and because of the blower I have the vacuum advance diconnected. The idle speed is at 850 RPM out of gear and about 750 in gear. The roller cam gives it a pretty racey idle. Also I have an 850 double pumper on top of the blower with the Percys adjust a jets setup to emulate 76 jets in both the front and rear metering plates.

I kinow that it seems strange that it runs hot with all of the cooling devices I have but I think that you guys have me on the right track!
 
Dartman1969 said:
Can you post some pictures so we can see the design?
~Michael
Click to expand...


Absolutely I will post pictures before and after mods. I think that when we get this sorted out that this tread will help a lot of others with the same problem. I'm on the road for business until Friday but I will get on it when I get home.

Thanks for all of the help!
 
You said that when you put on your hood, and your car was idling in your driveway it also got hot. I'm wondering if the hot air from your engine (do you have headers to heat up your engine bay?) is getting back into your engine through the carb and that is not helping keep your engine cool. I've thought about putting some sort of snorkel on my carb so it gets cool air from outside the engine bay on my Barracuda - would that also work for your trouble as well? There are a couple of people that have done something similar - I think I've seen some sort of cool air intake using something off a Jeep. I just haven't made it to my local Pick and Pull yet.
 
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