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396 BBC Running too hot

21K views 22 replies 12 participants last post by  BBCMudbogger 
#1 ·
The motor is a 396 BBC bored .060 over. I can start the car and drive around for 15-20 minutes before it begins to really heat up. Fans are set to come on the minute i start the car. I can cruise around at 60 mph and keep a pretty constant temp (170-190) when its 75-85 degree F out side when its 95+ the car will run up to 200-210 but stay steady until i hit a light or slow down to 40 or under. Im running about 40/60 coolant/water mix. The water pump is being over driven to move more water. Just last night the cap actually started leaking after i let it get up to about 230 before shutting it off the night before. I've been doing a lot of research and wanted your opinions. Would a higher pressure rated cap help fix this problem along with some redline water wetter? Should i put a pusher fan in the front of the radiator because it seems like im having an airflow issue? Build a shroud directing the air from the grill directly to the radiator? There isn't much room in the engine bay so im wondering if the hot air being sucked in by the carb is helping in the heating process? No cowl hood and the hood sits right ontop of the carb.

Thanks for any help!


So here is some info on the motor:
396 BBC bored .060 over
TRW forged pistons .360 dome
Shot peened connecting rods with ARP wavloc rod bolts
Stock crank polished
Merlin oval port cylinder heads with 119 cc combustion chambers, heads have had the combustion chambers polished, bowl areas of heads have been polished as well
2.30 intake valves, 1.88 exhaust valves double springs
Comp cam, lift is .595 on exhaust and intake, 260/260 degree duration at .50
Comp cam stainless steel roller rocker arms ratio is 1.7
Weiand stealth intake
Barry grant race prepped silver claw 850 cfm carb, venturis have been polished
Mallory comp 9000 dist
Mallory hyfire VIIIA ignition box
2800 stall converter from TCI
Weiand water pump
Griffon aluminum radiator
Flex a lite fans – 1 – 16” fan and 1 – 10” fan larger fan on the drivers side and smaller on the passenger side. Not enough room to put two large fans due to the clearance between the radiator and the water pump pulley
 
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#2 ·
What vehicle is this in? Does it have a air dam under the front end?
Does the radiator have a overflow connected to it? Chevy systems use a overflow to vent the system and if it`s plugged off it`ll run hot.
What temp thermostat? Have you checked the thermostat to see if it`s any good? I`ve bought many over the years and 3 of them were bad new out of the box. Pull your current thermostat and place it in a pot of water, turn the heat on and watch it, check the temp it opens at then turn off the heat and check the temp it closes, if it takes a long time to close you found the problem. Lastly, if it were I, I would install a 7 blade clutch fan with a shroud, it`ll cool it far better than electrics will. Is the timing advance set correctly? is it running too lean? as you see there`s lots of things to check.
 
#4 · (Edited)
DoubleVision said:
What vehicle is this in? Does it have a air dam under the front end?
Does the radiator have a overflow connected to it? Chevy systems use a overflow to vent the system and if it`s plugged off it`ll run hot.
What temp thermostat? Have you checked the thermostat to see if it`s any good? I`ve bought many over the years and 3 of them were bad new out of the box. Pull your current thermostat and place it in a pot of water, turn the heat on and watch it, check the temp it opens at then turn off the heat and check the temp it closes, if it takes a long time to close you found the problem. Lastly, if it were I, I would install a 7 blade clutch fan with a shroud, it`ll cool it far better than electrics will. Is the timing advance set correctly? is it running too lean? as you see there`s lots of things to check.
Vehicle is a 73 Nova. No air dam under front end
It does have an overflow connected to it, just a small polished canister. Its a 160 t stat. The thermostat is good.
How would i do the clutch fan with the pulleys so close to the radiator?
I dont know what the timing advance is set to ill have to check.
I could do a shroud with the largest elec fan i could buy for it and a meziere 300 series 55gpm water pump? Maybe build a directional shroud from the grill to the radiator to direct more air into the radiator so none of it trys to bypass it? Of course i want to save money but if $500 is what will fix the problem without spending 20 hours of my time diagnosing and fiddling ill spend it.
 
#5 ·
Ignitrous said:
The motor is a 396 BBC bored .060 over. I can start the car and drive around for 15-20 minutes before it begins to really heat up. Fans are set to come on the minute i start the car. I can cruise around at 60 mph and keep a pretty constant temp (170-190) when its 75-85 degree F out side when its 95+ the car will run up to 200-210 but stay steady until i hit a light or slow down to 40 or under. Im running about 40/60 coolant/water mix. The water pump is being over driven to move more water. Just last night the cap actually started leaking after i let it get up to about 230 before shutting it off the night before. I've been doing a lot of research and wanted your opinions. Would a higher pressure rated cap help fix this problem along with some redline water wetter? Should i put a pusher fan in the front of the radiator because it seems like im having an airflow issue? Build a shroud directing the air from the grill directly to the radiator? There isn't much room in the engine bay so im wondering if the hot air being sucked in by the carb is helping in the heating process? No cowl hood and the hood sits right ontop of the carb.

Thanks for any help!


So here is some info on the motor:
396 BBC bored .060 over
TRW forged pistons .360 dome
Shot peened connecting rods with ARP wavloc rod bolts
Stock crank polished
Merlin oval port cylinder heads with 119 cc combustion chambers, heads have had the combustion chambers polished, bowl areas of heads have been polished as well
2.30 intake valves, 1.88 exhaust valves double springs
Comp cam, lift is .595 on exhaust and intake, 260/260 degree duration at .50
Comp cam stainless steel roller rocker arms ratio is 1.7
Weiand stealth intake
Barry grant race prepped silver claw 850 cfm carb, venturis have been polished
Mallory comp 9000 dist
Mallory hyfire VIIIA ignition box
2800 stall converter from TCI
Weiand water pump
Griffon aluminum radiator
Flex a lite fans ? 1 ? 16? fan and 1 ? 10? fan larger fan on the drivers side and smaller on the passenger side. Not enough room to put two large fans due to the clearance between the radiator and the water pump pulley
Utah means altitude, altitude means lots of attention to mixture and timing.

The fans are what, electric, water pump driven?

If the carb is jammed up against the hood that probably means no aircleaner or flow guides. Lack of proper air entry control will mess up the mixture because of turbulence in the ventures and boosters, this needs to be corrected. Polished venturis in the carb and ports in the head, why? Polished surfaces reduce flow because the boundary layer likes to stick to them. The carb should never be allowed to suck hot under hood air, this greatly reduces the octane value of the fuel used and leads to detonation and preignition.

High volume water pumps and high flow thermostats usually work at cross purposes against engine cooling, if you're going to drive on the street, just use street stuff and forget the whiz bang faux racer junk. The race track and the street are two different engineering problems, what works in one place doesn't necessarily transfer to the other. Water wetter is usually good for 5 degrees or less, don't think that's going to help, increasing system pressure is no help, nor is a cooler thermostat. This system, assuming no lean mixture or retarded timing (cam and or distributor) issues, shows classic not enough radiator and not enough air flow thru the radiator. Cruse overheating being not enough radiator, stop and go not enough air flow. A chin air dam helps a lot a cruise speeds by forming a low pressure area under the engine compartment which helps pull more air thru the radiator. Running the fans at cruise speeds just gets in the way of airflow, fans can't come close to the amount of air being rammed past the grill. Ducting between the radiator and the grill is useful if there is more than a couple, 3 inches between them.

I see lots of problems with aluminum radiators, lots of Chevys from the 1970s came with big blocks, just get a replacement GM radiator for something that came with a 396/427 and bolt it in. Use a factory fan shroud and a factory fan with a temp clutch. If you're married to aluminum radiator then simplify the fans with a factory shroud and clutch fan, put on a separate engine oil cooler and if an automatic a separate tranny oil cooler. This will knock 20-40 degrees off the radiator. Early 70s Novas could be had with 396s so solving these problems shouldn't require going further than the GM parts book.

Bogie
 
#6 ·
You have what sounds like a classic lack of air flow issue. I say this because you say it is ok at speed. The forced air flow of the car moving is cooling the radiator. A shroud may help or maybe 1 large fan. Some of the after market fans can actually restrict almost as much as they help.
On the smaller fan you may do a little better if you can move it closer to the top of the radiator as well.
 
#7 ·
So tonight i took the hood off, jacked up the front of the car filled up/started/finished filling the radiator and stuck a new 16psi cap on. Dropped it down and started it up. Drove around until it was warmed up and at about 165 it started spewing coolant out the cap so i went back home pulled the cap and squeezed on the over flow tube and coolant went back into the radiator...took off the cannister and emptied it out completely. Radiator still looked full so i stuck the same cap back on jumped in and took off again. It warmed up to about 183 and stayed there for 15 maybe 20 minutes of driving stop and go in my neighborhood cruising no faster than 40 usually trying to go about 20-35. Would romp on the throttle to put a good load on the motor and it was staying steady for a good while! I was so excited! WOOOOO! ITS FIXED! ......
....
....
No....no its not, its starting to heat up...190...195..it stayed around 195-200 for about 5 minutes then continued its climb as i was going 10-15 through this little apartment complex next to my neighborhood. Around 210 it started spewing coolant out of the cap again. Checked the over flow and there is a little coolant in it buts its not full......

***?! I took the hood off and it really seemed like it helped out. Then...????? why would it just start heating up again and spewing coolant out of the cap at 210? Im starting to wonder if that radiator is jacked? I think its made for the roundy-rounds. Looking in the top of the cap i can see two rows of round fins and i watched the coolant flowing really well as i was filling it up the rest of the way after i started the car. It doesn't have a drain on the radiator you have to take the bottom hose off. The bottom hose i think may be a little long as it comes off the radiator and makes a long u-turn up to the water pump. Its that polished metal accordian style hose.

Ideas? I dont want to just throw money at the problem. What should be the next step? Is there anything else? I've done a thermal temp test and the radiator will cool 30-40 degrees across, the timing is right on, valves are all adjusted correctly. Im running 10w-40 oil. If the motor was put together too tightly it could cause this problem but by now i'd be hearing other issues and have loads of metal in my oil. Everything is clean as a whistle.

With the way the car was running with that cap maybe i need more pressure? Maybe the radiator is FUBAR? Its a closed system should i get a vented overflow? :sweat: :sweat: :sweat: :sweat:
 
#9 ·
Sounds like my 396 when I didn't use the bypass hose.

that 3/4 inch heater hose that goes between the water pump and intake (bypass hose) is required if you are using a regular t-stat.

use a gutted t-stat to see if it helps. A gutted t-stat is a cheap t-stat with the spring and valve cut out (just the washer portion). If it works with the gutted t-stat then you have a bypass issue. Funny thing is my 454 does care if it has a bypass hose but my 396 has temperature fits without it.
 
#10 ·
If the cap is spewing at 210 it has a problem replace it.Then (I know no one wants to hear this)dump the electric fans and water pump get a stock clutch fan and good shroud with a stock water pump and your problems will be gone.Also if it has overheated take a light and look at the radiator tubes thru the fins if they are swelled th rad is toast aluminum radiators will do this with to much pressure and then not allow enough airflow thru the rad.
 
#12 ·
454C10 said:
Sounds like my 396 when I didn't use the bypass hose.

that 3/4 inch heater hose that goes between the water pump and intake (bypass hose) is required if you are using a regular t-stat.

use a gutted t-stat to see if it helps. A gutted t-stat is a cheap t-stat with the spring and valve cut out (just the washer portion). If it works with the gutted t-stat then you have a bypass issue. Funny thing is my 454 does care if it has a bypass hose but my 396 has temperature fits without it.
I have that installed but maybe its on the wrong side of the water pump? There are two places you can connect that to the waterpump. Its connected on the right.
I will have to cut up a t-stat.
Im going to buy another cap and an air cleaner so i can drive around with an aircleaner on the car and hopefully a radiator cap that works. Keep the hood off until i fix the problem.
Ill also check to see if the tubes are warped on the radiator. Before it started spewing out of the cap the car would get up to 230 and never leak fluid. Maybe i did crack a head?
Im wondering if a radiator from a 1970 camaro with a 396 will fit in my 73 nova? If so i may just buy that stock 70 camaro radiator and start going back to "stock"

That wiki article is very detailed and has loads of useful information. Thanks for the link.
 
#13 ·
Ignitrous said:
So tonight i took the hood off, jacked up the front of the car filled up/started/finished filling the radiator and stuck a new 16psi cap on. Dropped it down and started it up. Drove around until it was warmed up and at about 165 it started spewing coolant out the cap so i went back home pulled the cap and squeezed on the over flow tube and coolant went back into the radiator...took off the cannister and emptied it out completely. Radiator still looked full so i stuck the same cap back on jumped in and took off again. It warmed up to about 183 and stayed there for 15 maybe 20 minutes of driving stop and go in my neighborhood cruising no faster than 40 usually trying to go about 20-35. Would romp on the throttle to put a good load on the motor and it was staying steady for a good while! I was so excited! WOOOOO! ITS FIXED! ......
....
....
No....no its not, its starting to heat up...190...195..it stayed around 195-200 for about 5 minutes then continued its climb as i was going 10-15 through this little apartment complex next to my neighborhood. Around 210 it started spewing coolant out of the cap again. Checked the over flow and there is a little coolant in it buts its not full......

***?! I took the hood off and it really seemed like it helped out. Then...????? why would it just start heating up again and spewing coolant out of the cap at 210? Im starting to wonder if that radiator is jacked? I think its made for the roundy-rounds. Looking in the top of the cap i can see two rows of round fins and i watched the coolant flowing really well as i was filling it up the rest of the way after i started the car. It doesn't have a drain on the radiator you have to take the bottom hose off. The bottom hose i think may be a little long as it comes off the radiator and makes a long u-turn up to the water pump. Its that polished metal accordian style hose.

Ideas? I dont want to just throw money at the problem. What should be the next step? Is there anything else? I've done a thermal temp test and the radiator will cool 30-40 degrees across, the timing is right on, valves are all adjusted correctly. Im running 10w-40 oil. If the motor was put together too tightly it could cause this problem but by now i'd be hearing other issues and have loads of metal in my oil. Everything is clean as a whistle.

With the way the car was running with that cap maybe i need more pressure? Maybe the radiator is FUBAR? Its a closed system should i get a vented overflow? :sweat: :sweat: :sweat: :sweat:
I sighted a while back that some of these aluminum radiators just have problems on the street and suggested you drop back to the SS cars of the late 60s early 70s for an OEM brass/copper solution. A question on the filler cap, they are usually on the return to the pump side of the radiator, does your radiator fit this or is the cap on the engine to radiator return side?

What about the bypass? I have no explanation for this but many Chevy's, big and small block, don't like to be operated without the large return hoses of the heater circuit.

Overflow should go to a puke tank and the cap should be dual venting by that I mean it vents pressure coolant to the tank and when the engine cools, the vacuum formed in the cooling system siphons the coolant back from the puke tank into the radiator. A normal OEM style cap does this. You stated that you removed coolant from a tank, do you mean the overflow tank (puke tank) or one of the side tanks of the radiator. Normal operation of an engine results in a lot of fluid expansion, the pressure cap is there to place an upper end pressure limit on the system, the pressure is caused by the expansion of the liquid and some to vapor, the pressure is intended to raise the boiling point of the fluid which allows the engine to be run at a higher more efficient temperature than can be done with an atmospheric pressure system, it also makes for a consistent system pressure that doesn't change the fluid's boiling point with altitude changes. The ultimate pressure selection by the cap is also a structural protection for the cooling system it is set for a point where the pressure is maintained lower than the point were a failure of a hose, gasket, or radiator would occur. So finally the point I was trying to get at about expansion of hot fluids, if you removed fluid when the system is hot, then when it cools and contracts there will not be sufficient fluid in the system and the engine will overheat all the sooner.

So is summary my first suggestions are:

1) A vented cap with a connection to an overflow tank such that excess coolant is returned to the radiator as it cools.

2) Installation of an OEM heater circuit bypass. This doesn't mean you have to have a heater core, just a hose that makes a connection from the engine side of the thermostat back to the intake side of the water pump.

3) I'd highly recommend that if you're over or under driving the water pump, that you return to OEM pulley ratios.

4) I think the pump needs to be checked to be sure it's rotation is compatible with the belt drive system. Stock V-belt has a clockwise rotation (viewed from the front), stock serpentine uses a counter clockwise rotation. Aftermarket serpentine systems can be either rotation, you need to look at how the belt wraps the pulley to see which way the pump needs to turn.

Bogie
 
#14 ·
oldbogie said:
I sighted a while back that some of these aluminum radiators just have problems on the street and suggested you drop back to the SS cars of the late 60s early 70s for an OEM brass/copper solution. A question on the filler cap, they are usually on the return to the pump side of the radiator, does your radiator fit this or is the cap on the engine to radiator return side?

What about the bypass? I have no explanation for this but many Chevy's, big and small block, don't like to be operated without the large return hoses of the heater circuit.

Overflow should go to a puke tank and the cap should be dual venting by that I mean it vents pressure coolant to the tank and when the engine cools, the vacuum formed in the cooling system siphons the coolant back from the puke tank into the radiator. A normal OEM style cap does this. You stated that you removed coolant from a tank, do you mean the overflow tank (puke tank) or one of the side tanks of the radiator. Normal operation of an engine results in a lot of fluid expansion, the pressure cap is there to place an upper end pressure limit on the system, the pressure is caused by the expansion of the liquid and some to vapor, the pressure is intended to raise the boiling point of the fluid which allows the engine to be run at a higher more efficient temperature than can be done with an atmospheric pressure system, it also makes for a consistent system pressure that doesn't change the fluid's boiling point with altitude changes. The ultimate pressure selection by the cap is also a structural protection for the cooling system it is set for a point where the pressure is maintained lower than the point were a failure of a hose, gasket, or radiator would occur. So finally the point I was trying to get at about expansion of hot fluids, if you removed fluid when the system is hot, then when it cools and contracts there will not be sufficient fluid in the system and the engine will overheat all the sooner.

So is summary my first suggestions are:

1) A vented cap with a connection to an overflow tank such that excess coolant is returned to the radiator as it cools.

2) Installation of an OEM heater circuit bypass. This doesn't mean you have to have a heater core, just a hose that makes a connection from the engine side of the thermostat back to the intake side of the water pump.

3) I'd highly recommend that if you're over or under driving the water pump, that you return to OEM pulley ratios.

4) I think the pump needs to be checked to be sure it's rotation is compatible with the belt drive system. Stock V-belt has a clockwise rotation (viewed from the front), stock serpentine uses a counter clockwise rotation. Aftermarket serpentine systems can be either rotation, you need to look at how the belt wraps the pulley to see which way the pump needs to turn.

Bogie
The cap is on the return side of the radiator where the fluid would go back to the water pump.
I have a puke tank but it is completely sealed. Its just an aluminum can with an inlet to accept the puke from the radiator and outlet that can be unscrewed from the bottom to release what ever the puke tank is holding. This is where i emptied the coolant from. Not from the radiator.

The pump is being driven clockwise. The belt runs around the crank up around the alternator, over across the waterpump and back around clockwise. Alternator is on the left side of motor looking at the front of the car.
There is a return hose from the water pump connected to the intake manifold. There is only one spot to connect it directly beneath the outlet from the t-stat. There are two spots on the water pump where it can be connected, right or left of the pulley.
The system has a pulley that is over-driving the water pump.
I still have the heating system hoses and box the hoses are not currently connected to the system. This car did not come with a 396 though so im not sure why it would matter if this system was hooked up to the heater or not? I might just be confused.

1)I do have a vented cap. My definition may differ from yours?
2) I think the bypass may be going from the t-stat to the output of the water pump instead of the inlet side. Ill check and reverse this if thats the case.
3)If #2 doesnt work ill try this
4)I saw the water flowing last night and it was moving from the engine side through the radiator back down to the water pump inlet side. Its flowing the correct direction. I have 2 separate belts, 1 driving alt. and water pump. the other driving the power steering.

Thinking i might just go buy that radiator today, its only $130....
 
#15 ·
oldbogie said:
I sighted a while back that some of these aluminum radiators just have problems on the street and suggested you drop back to the SS cars of the late 60s early 70s for an OEM brass/copper solution. A question on the filler cap, they are usually on the return to the pump side of the radiator, does your radiator fit this or is the cap on the engine to radiator return side?

What about the bypass? I have no explanation for this but many Chevy's, big and small block, don't like to be operated without the large return hoses of the heater circuit.

Overflow should go to a puke tank and the cap should be dual venting by that I mean it vents pressure coolant to the tank and when the engine cools, the vacuum formed in the cooling system siphons the coolant back from the puke tank into the radiator. A normal OEM style cap does this. You stated that you removed coolant from a tank, do you mean the overflow tank (puke tank) or one of the side tanks of the radiator. Normal operation of an engine results in a lot of fluid expansion, the pressure cap is there to place an upper end pressure limit on the system, the pressure is caused by the expansion of the liquid and some to vapor, the pressure is intended to raise the boiling point of the fluid which allows the engine to be run at a higher more efficient temperature than can be done with an atmospheric pressure system, it also makes for a consistent system pressure that doesn't change the fluid's boiling point with altitude changes. The ultimate pressure selection by the cap is also a structural protection for the cooling system it is set for a point where the pressure is maintained lower than the point were a failure of a hose, gasket, or radiator would occur. So finally the point I was trying to get at about expansion of hot fluids, if you removed fluid when the system is hot, then when it cools and contracts there will not be sufficient fluid in the system and the engine will overheat all the sooner.

So is summary my first suggestions are:

1) A vented cap with a connection to an overflow tank such that excess coolant is returned to the radiator as it cools.

2) Installation of an OEM heater circuit bypass. This doesn't mean you have to have a heater core, just a hose that makes a connection from the engine side of the thermostat back to the intake side of the water pump.

3) I'd highly recommend that if you're over or under driving the water pump, that you return to OEM pulley ratios.

4) I think the pump needs to be checked to be sure it's rotation is compatible with the belt drive system. Stock V-belt has a clockwise rotation (viewed from the front), stock serpentine uses a counter clockwise rotation. Aftermarket serpentine systems can be either rotation, you need to look at how the belt wraps the pulley to see which way the pump needs to turn.

Bogie
The cap is on the return side of the radiator where the fluid would go back to the water pump.
I have a puke tank but it is completely sealed. Its just an aluminum can with an inlet to accept the puke from the radiator and outlet that can be unscrewed from the bottom to release what ever the puke tank is holding. This is where i emptied the coolant from. Not from the radiator.

The pump is being driven clockwise. The belt runs around the crank up around the alternator, over across the waterpump and back around clockwise. Alternator is on the left side of motor looking at the front of the car.
There is a return hose from the water pump connected to the intake manifold. There is only one spot to connect it directly beneath the outlet from the t-stat. There are two spots on the water pump where it can be connected, right or left of the pulley.
The system has a pulley that is over-driving the water pump.
I still have the heating system hoses and box the hoses are not currently connected to the system. This car did not come with a 396 though so im not sure why it would matter if this system was hooked up to the heater or not? I might just be confused.

1)I do have a vented cap. My definition may differ from yours?
2) I think the bypass may be going from the t-stat to the output of the water pump instead of the inlet side. Ill check and reverse this if thats the case.
3)If #2 doesnt work ill try this
4)I saw the water flowing last night and it was moving from the engine side through the radiator back down to the water pump inlet side. Its flowing the correct direction. I have 2 separate belts, 1 driving alt. and water pump. the other driving the power steering.

Thinking i might just go buy that radiator today, its only $130....
 
#19 ·
Just wanted to say thanks to all those who gave me input on this.
This problem is fixed now...Its funny because the expensive set up i had didn't do the job. Dont ever buy a "Shiraco style 2 core aluminum radiator"....

So I took the hood off and began to see an improvement, threw a air filter on and saw a bit more of an improvement, enriched my mix a little and saw a little more. Still wasn't fixed but i could drive around longer at slower speeds and keep a steady 180-190 temp for 20-30 minutes after that it would heat up faster than a hot pocket in a microwave.

Bought a $36 stock water pump from a local parts store, a $12 190 degree t-stat (did not gut it) and a stock size 3 core radiator made for my year and model of car, not for the specific motor, but the seller gauranteed me it would cool 800hp no problem or my money back. So i paid $235 for the radiator +fan combo, slapped it all in and went for a ride.
Car doesn't go over 200-205 Fahrenheit at any speed while im moving. I can cruise around town at 5-20mph and it sits at a steady temp. The stock water pump is using the over drive pulley still.

This new radiator is considerably smaller compared the one i had on it, and only 1 16" electric fan, not even one of the expensive electric fans i purchased. If i warm it up to 205 and then let it sit and idle it will begin to heat up after 5-10 min or so. I think ill need to buy a small pusher fan to put on the front so if i ever get stuck in traffic i can turn on that "Aux" fan to help move some more air. Im sure a mech fan with a shroud would do the job but I dont think i have the clearance for the shroud and fan...besides I'd rather have the elect fan with another fan set up on a switch i can turn on when its needed than take the loss of HP.

So because I did 2 parts at once and wanted to see what the problem really was I did a little study after it was fixed. Took off the stock water pump and put my expensive weiand pump back on.
Results: The larger 2 core radiator DOES NOT cool more efficiently than the smaller 3 core radiator will. 50/50 mix in the 3 core cools better than any mixture i tried in the 2 core.
 
#20 ·
Glad you got it worked out.

I had a near identical issue with an off-road rig. When I built it, I wanted to make sure I would never have to battle heat. So I bought the best I could get for pump, rad and fans.
Well, it got hot. I just "KNEW" it could not be my zillion dollar aluminum radiator, so I started replacing everything else. The first thing I did was ditch the electric fans. I like electric fans on an off-road rig for many reasons, but went with a large clutch fan. Still hot. Changed the water pump to a different brand, still hot.
Just for the heck of it, I pulled out the aluminum radiator and installed the old, worn out, stock one and it stayed cool.

Now, I'm not going to throw any radiator manufactures under the bus here...but lets just say you would know the name.

I am currently running a new stock radiator, went back to my electric fans and a mechanical water pump. Never gets hot. Even went crawling along on a hot day.

Sometimes the factory knew what they were doing I guess...go figure. ;)
 
#22 ·
Ignitrous said:
Just wanted to say thanks to all those who gave me input on this.
This problem is fixed now...Its funny because the expensive set up i had didn't do the job. Dont ever buy a "Shiraco style 2 core aluminum radiator"....

So I took the hood off and began to see an improvement, threw a air filter on and saw a bit more of an improvement, enriched my mix a little and saw a little more. Still wasn't fixed but i could drive around longer at slower speeds and keep a steady 180-190 temp for 20-30 minutes after that it would heat up faster than a hot pocket in a microwave.

Bought a $36 stock water pump from a local parts store, a $12 190 degree t-stat (did not gut it) and a stock size 3 core radiator made for my year and model of car, not for the specific motor, but the seller gauranteed me it would cool 800hp no problem or my money back. So i paid $235 for the radiator +fan combo, slapped it all in and went for a ride.
Car doesn't go over 200-205 Fahrenheit at any speed while im moving. I can cruise around town at 5-20mph and it sits at a steady temp. The stock water pump is using the over drive pulley still.

This new radiator is considerably smaller compared the one i had on it, and only 1 16" electric fan, not even one of the expensive electric fans i purchased. If i warm it up to 205 and then let it sit and idle it will begin to heat up after 5-10 min or so. I think ill need to buy a small pusher fan to put on the front so if i ever get stuck in traffic i can turn on that "Aux" fan to help move some more air. Im sure a mech fan with a shroud would do the job but I dont think i have the clearance for the shroud and fan...besides I'd rather have the elect fan with another fan set up on a switch i can turn on when its needed than take the loss of HP.

So because I did 2 parts at once and wanted to see what the problem really was I did a little study after it was fixed. Took off the stock water pump and put my expensive weiand pump back on.
Results: The larger 2 core radiator DOES NOT cool more efficiently than the smaller 3 core radiator will. 50/50 mix in the 3 core cools better than any mixture i tried in the 2 core.

This is an all too common discovery, glad you got it working.

Much of this whiz-bang cooling system stuff just isn't effective on the street. As far as power savings from electric fans and electric coolant pumps go for that matter, the power saved is highly overrated and only occurs, if at all, way up at WOT red line RPM. These fans, or pumps, that claim to save you 20 or more horsepower only do so in an engine speed range where the crank driven equivalent gadget is absorbing that much power. At lower engine speeds the power taken off the crank by these ancillaries is a lot less and usually not noticeable; either as a decrement against performance, nor as a cooling issue.

It's important to keep in mind that what's designed for a race situation is not useful for the street. Further, different types of racing require unique solutions. For instance, when drag racing one can use an electric coolant pump to free up a few horses. In a drag race the running time is short and a charged battery will have sufficient reserve to run the pump for the required time. However, in an endurance event of several hours a battery of reasonable size and weight does not have suitable capacity to run a pump for the event duration. That would require an alternator of sufficient output to sustain the pump's motor, which would requiring sizing the alternator for not only the power consumption of the pump motor but also all the looses and inefficiencies inherent to electrical generation and distribution. This in the end results in a very large alternator that would remove more power than just directly turning the pump off the crankshaft.


Bogie
 
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