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Discussion Starter #1 (Edited)
Like the title says my temps are out of control and I'm pulling my hair out trying to figure out the problem. Here is what I have:

355 (~420-440HP)
Aluminum Rad from some Ford product. Measures 25" (w/o tanks) x 16" x 2.25"
Taurus electric fan
Proform electric water pump
Fenderwell headers
50/50 mix of water and Chrysler antifreeze with a water-wetter type product
No thermostat (tried a 180 with the same results)

Generally temps sit in the 205-210 range after driving around for a bit. The other day they hit 230 degrees on the highway and I had to pull over to let it cool down.

The cooling system was put together by my brother who has worked with automotive heating and cooling systems for ~8yrs. The water pump is the only piece I bought that wasn't part of the original plan. I know some people shy away from the electric pumps but, other than reliability concerns, I don't see why it would be the culprit as it flows better than a mechanical Victor Jr. pump up to ~3000rpm and flows about even with a stock pump after that point.

The only things I can come up with are A) the carb tune is way out of whack or B) underhood airflow is poor because of the fenderwell headers.

I've included some pics (hope some of you guys don't mind I borrowed a pic or two from the Show and Shine area) of the approximate area that I cut from the inner fenders to let the headers pass through. I'm thinking the part I left intact is blocking the flow of air around the headers and causing excessive heat to build up in that area. The headers just barely clear the portion of the inner fender that was left intact.
Pic 1 Red represents area that was removed and green is what stayed.
Pic 2 Yellow is what stayed

Is my theory sound or would you guys suggest I look somewhere else?
 

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I don't think the headers have anything to do with it. I've been involved with a few cars with fenderwell headers and they didn't have overheating problems.
What speed do you run the fan? What is your radiator outlet temperature?
As I recall, the lower third of the radiator is occluded by the valence behind the bumper. Does your entire radiator get adequate air?
 

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Put it this way, a stock set-up would be more than enough to adequately cool your engine. I'd be looking at everything that isn't stock, especially the water pump and the fan. I've seen a lot more guys have overheating issues trying to run electric fans and water pumps than I've ever seen that just running a stock cooling system. There must have been about a thousand posts on this forum with guys with overheating issues and guess what? The majority of them involve trying to run electric fans and a lot are trying to run electric water pumps too.

Not saying that you can't run electric pumps and fans if they are efficient enough but that's where I would be looking. A cooling system isn't very complicated. You have a radiator, a water pump, a fan, and a thermostat - that's it.

When temps climb at highway speeds, that generally points towards the water pump as the first thing to suspect since the fan doesn't do anything at highway speeds unless it is impeding air flow through the radiator. I'd put the stock water pump back on it and see what it does. If your problem goes away you know what it was. If that doesn't solve it, put the mechanical fan on too. If that doesn't solve it, the only things left are the radiator and the thermostat and my guess would then be that it's the radiator. My money's on the water pump as the culprit though.;)
 

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Also too, check to see if your carb is running too lean or your timing is too advanced.
 

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Where is the temp sensor located? In the head or in the thermostat area of the intake? My friend at Freightliner who works in the R&D dept told me they measure the temp into and out of the radiator and motor as well as the flow rates as part of their tests of cooling systems on their chassis. I run electric pumps on my drag cars but they are a fixed flow rate and I would think a RPM controlled flow would be better but that's just an opinion. RM
 

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I have the Proform pump on mine and it cooled the 14.5-1, half-filled with HardBlok, 414", no steam hole in the heads, engine just fine.
Mine always creeps up at highway speeds no matter what pump/fan/radiator combo has been on the car during the 20+ years I've owned it, but never enough to be a concern. The Griffin aluminum radiator was the best thing I've ever done for the cooling system--the Vintage Air Monster fan was the next best thing, but it did cause electrical issues due to the massive amp draw(60 amps at startup, 36 continuous) After going to a 140 amp alternator, it has been pretty reliable. Do you have enough amperage to run everything on the car? Maybe you're running out of power?
 

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DriveEFO had a Proform pump and no problems that I am aware of.

I have a CSR pump, Flexlite Syclone 2500 CFM fan, 160 deg thermostat, and a stock radiator with no major cooling problems. On a real hot day the temp will creep up to 170-180 but seems to stabilize and not be a concern.
 

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If your engine stays cool at idle and lower speeds but heats-up at higher speed, that eliminates the fan. It is then down to either the water pump or the radiator. My money's on the water pump.

I run a mechanical water pump on my 406 and the temp doesn't climb at highway speeds. If anything, it climbs a little bit sitting at a red light on a hot day. That makes sense and is how a normally-functioning cooling system behaves. If your temp climbs at highway speeds, it usually means your water pump isn't pumping enough coolant.

If the car doesn't heat-up at idle, it usually points away from the radiator as the cause too. The only thing left is the water pump.

In any case, you'll never know what it is untill you go through a process of elimination. Instead of trying to work around what is most-likely the cause, I'd replace the water pump with the original mechanical pump and see what happens. I bet it runs cooler.;)
 

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Discussion Starter #10
I was pretty leary of running a Proform pump when I was originally looking into it. After some research though it appears that the Proform pump will outflow a mechanical Victor Jr. up to about 2200rpm. I'll bet it flows pretty close to a stock pump at higher rpms so it could be the problem but I think it should be adequate. I never had a stock pump for this engine so I'd have to source that and the necessary pulleys to test that variable. I might have to do that in the end but I'd like to eliminate other possibilities first.

The temp sensor is located in the driver side head. I've tried a mechanical and digital sender and both report about the same temps.

The Taurus fan puts out ~3800cfm on high (which is what I generally run it at) so I don't think that's the culprit. I should check and see how the alternator is holding up though. I'm running a 100-amp unit and the water pump draws 5 amps and the fan is around 15-17amps. The only other big draw would be the headlights and the ignition system.

I'm not sure of the radiator outlet temps. I'll have to figure out some way of reading that. I'm also not sure if the radiator is being blocked by the valence under the bumper. It seems to get adequate airflow but I'm not sure on that one.

Is there a possibility that the air is stalling under the hood at highway speeds? At idle the airflow from the fan wouldn't be that great so airflow might not be a problem but at highway speeds there is a ton of air coming into the engine bay and if airflow is poor could that be my problem? I guess I could test that theory by taking my hood off.
 

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The few times I had the temp sensor in the head the temp measured about 10 degrees higher than the thermostat port. Maybe try moving the pick up sensor to the thermostat area and see what it does. If the water in the radiator isn't cooking but the water coming out of the motor is really that hot then flow rates would seem low to me. RM
 

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I just finished dealing with an overheating problem in my car. It ran hot all the time. I replaced the factory radiator with a 31x19 aluminum (Northern) and trimmed out the core support some to expose more of the radiator. Now when driving it runs a steady 180 degrees, vs 220 before. With the new radiator and stop and go it will creep up to 195, vs 230-240 before. I replaced the single electric fan I had with a dual fan setup to help the stop and go temps but I had to go out of town on a business trip and have not tested it. I guess every problem could be different but the radiator was the key for me.
 

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Discussion Starter #14
Good luck.:)

Everything points to the water pump though.;)
I do appreciate your input and the problem may very well be the pump. I just don't have the $$ to buy a mechanical pump and pulleys to test that theory until I've eliminated the other possibilities.

McCoy- I need to drill and tap the port next to the thermostat. I have a temp switch for the fans and pump in the available port on the intake. Poor flow may be the problem though after you explained it that way so maybe a new pump is in order.

bdog- This model of radiator has been used with great success with a 427 sbf and a stout 396 bb. My motor isn't as knarly as theirs so I'm thinking I should be ok. Glad you got your problems worked out with your car.
 

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I guarantee you that more Novas run hot on the hiway than run cool. If you have a gear in the car this alone will aid in heating on the hiway, higher rpms, consider the fact that airflow across the engine is terrible on the Nova. Actually, with a V8 stuffed in there- aint nowhere for the air to go.

I'll bet you that you cruise the streets temp is ok, run the hiway temp climbs - It is an airflow problem, not a water flow problem. You can chase either all you want but with a mechanical pump, good T-stat, and adaquate electric fan around town the car should run around 202-05 in hot climate, on the hiway temp will climb rapidly, due to higher rpms and the fact that alot of the air is buffeted by the front of the car, rad. included, just don't flow good in the engine compartment. Especially having 1/3 of the rad. sealed off on the bottom from the bumper/valance panel.
Youd din't say what tranny you got either, bet its a TH350, or at least no OD which would help alot to lower engine rpms.
 

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Are your sure your alternator is putting out enough power to handle all those accessories?

Last I heard, the Taurus fan draws a whopping 40 amps on high speed....the 15-17amps you quote is for LOW speed. Add to that your electric water pump, and I would assume a whole mess of aftermarket gauges.

Keep in mind, too, that an alternator rated for 100amps isn't putting out 100amps at low speeds--that's MAX. If you can't supply enough power to your pump and fan, neither of the two will be working at 100%.

If it were me, I'd ditch the electric pump and see how things go from there. I bet it makes a noticeable difference.
 

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I guarantee you that more Novas run hot on the hiway than run cool. If you have a gear in the car this alone will aid in heating on the hiway, higher rpms, consider the fact that airflow across the engine is terrible on the Nova. Actually, with a V8 stuffed in there- aint nowhere for the air to go.

I'll bet you that you cruise the streets temp is ok, run the hiway temp climbs - It is an airflow problem, not a water flow problem. You can chase either all you want but with a mechanical pump, good T-stat, and adaquate electric fan around town the car should run around 202-05 in hot climate, on the hiway temp will climb rapidly, due to higher rpms and the fact that alot of the air is buffeted by the front of the car, rad. included, just don't flow good in the engine compartment. Especially having 1/3 of the rad. sealed off on the bottom from the bumper/valance panel.
Youd din't say what tranny you got either, bet its a TH350, or at least no OD which would help alot to lower engine rpms.
This is exactly the situation I'm faced with. I have a mild ZZ4 with a stock pump, small copper/brass radiator and electric fan. The fan does not appear to be connected with a relay, probably not good. Everything is new, but my temps climb on the high way. I may try a new, larger aluminum radiator and dual fans. We'll see what happens.
 

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Discussion Starter #19
Well I decided to heed some advice and experiment a little. I put the 180 degree Robert Shaw thermostat back in and it seemed to help a little. Cruising around at 40mph with the fan on low kept temps in the 195-205 range (measured at the head so intake temps should be 10 degrees lower I imagine). Went for a drive on the highway and temps were in the 205 range. Pulled off the highway, drove for a mile into a parking lot and let the engine idle. Temps hit 218-222 while sitting there with the fan on high. I sat there for awhile to see if temps would drop and they kept fluctuating from 210-220. Hit the highway again and temps dropped down to about 207. Headed onto the off ramp and temps spiked to 230 :(

I tried pulling the hood off before installing a thermostat and temps were about the same. Maybe a tad cooler.

Does that make sense to anyone? If it was the pump I'd assume that highway temps would be higher than sitting in a parking lot as the electric pump is supposed to shine at low rpms.

I'll borrow a multimeter from someone and see how the alternator is holding up. Where is the best place to measure the amp draw? At the pump and fan or at the alternator?
 

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The thing that has me wondering was you said the radiator was an aluminum from a ford product.
1. was it new or did you have it rodded out
2. is it a one row or a two row.
If it is a one row, then it is two small for the application, if it is a two row and not plugged, then you have an airflow problem or a water pump problem. Go with a good aluminum hi flow water pump (Mechanical)
Most times when a car heats up on the road at speed, it is a cooling flow problem, while if it heats at Idle or stop and go it is an air flow problem. I say most times, there are always the odd ducks.
 
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