with the plate on the back
Help Me Cool Down
- Thread starter T56MaxTorq
- Start date
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yellow rose
Overnight Sensation
It doesn't matter. If the fan is close enough to the radiator and pump speed is correct then the shroud really gets in the way (just like the fan) at MPH above about 10-15 MPH. It's not that complicated. The shroud is a fix for the fan being too far from the radiator. That's all. It ain't magic.
T56MaxTorq
Well-Known Member
I see what you mean. Forward speed overcomes the fan. My fan sits 1” from the radiator. I know that a fan or propeller works by reducing the air pressure in front of it and atmosphere then flows from high to low. So without a shroud it will still drop pressure from the surrounding area. I’m also at altitude so I have 1/5 less pressure and that harms radiator efficiency as well. I’m not sure if it will help my heat rise at idle unless I remove the shroud and get a big fan.
This is what I’m working with and the crank pulley. The small cap screw locks down the ignition wheel from rotating.
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Are you running a thermostat without a restrictor? I have seen flowing to fast through the radiator can be an issue.
Here is a issue I dealt with. I am not saying this is yours, But it would be worth checking.
I saw your motor is boosted. I have seen a blown head gasket take out a aluminum radiator . On newer cars they blow the plastic tanks off.. On welded race radiators it blows the tubes in the radiator up. They become round instead of being oval. When this happens it prevents air flow . You cannot physically see this in the car.
I noticed this with an electric fan running and I didn't feel air when standing at the fender. I put a piece of paper in front of the radiator and there was little to no suction. After I took the radiator out you could not see through it with a light behind it. I bought a new radiator. Cooling problems were gone.
High instant pressure from a high pressure head gasket failure will cause this when you blow a head gasket at rpm's or under high boost. As well as a radiator freezing. Just something I would check. You never know. A radiator not only needs to flow water . It needs to flow air . I have seen front mount inter-coolers and trans-coolers do the same thing.
Maybe your car has a air flow problem? If you have room to hold a bright light behind the radiator you should clearly see it through what ever is in front of it in all core areas. Easy to check. If you restrict air flow this could be your problem.
Just some info you may want to use. Steve
I saw your motor is boosted. I have seen a blown head gasket take out a aluminum radiator . On newer cars they blow the plastic tanks off.. On welded race radiators it blows the tubes in the radiator up. They become round instead of being oval. When this happens it prevents air flow . You cannot physically see this in the car.
I noticed this with an electric fan running and I didn't feel air when standing at the fender. I put a piece of paper in front of the radiator and there was little to no suction. After I took the radiator out you could not see through it with a light behind it. I bought a new radiator. Cooling problems were gone.
High instant pressure from a high pressure head gasket failure will cause this when you blow a head gasket at rpm's or under high boost. As well as a radiator freezing. Just something I would check. You never know. A radiator not only needs to flow water . It needs to flow air . I have seen front mount inter-coolers and trans-coolers do the same thing.
Maybe your car has a air flow problem? If you have room to hold a bright light behind the radiator you should clearly see it through what ever is in front of it in all core areas. Easy to check. If you restrict air flow this could be your problem.
Just some info you may want to use. Steve
BigBlockMopar
BigBlockMember
Do you have enough timing at idle?
I would use a 7-blade factory fan. The blades of those are usually made from aluminium.
I would use a 7-blade factory fan. The blades of those are usually made from aluminium.
famous bob
mopar misfit
Makes a hell of a lot of diff. , h.p. creates heat , the more u have the harder it is to keep cool. Mine absolutely wont cool w/o a shroud. And I have had the fan in about every position it can be put in, and about every fan known to man , I did experimenting with diff. combinations "all" last summer , to come up w/ what I`m running.
Exactly...every combo has different cooling needs.
Some don't need a shroud, some do.
It's not a case of if you park the fan close enough to the radiator it'll work every time.
It wont.
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T56MaxTorq
Well-Known Member
I can see light through it and my radiator cap is 16lbs. Never blown a head gasket. My radiator is just a little small for the engine I think. I also run a thermostat.
T56MaxTorq
Well-Known Member
I will check out a stock fan and see if it improves. I need to be flowing the most air I can. My timing is 15ish - Highest vacuum possible at idle
yellow rose
Overnight Sensation
This is just not true. Like the power valve timing issue, this old wives tale needs to die.
yellow rose
Overnight Sensation
Are you making 700 HP at idle or cruise? There's more to it than max HP.
Maybe you are turning the pump too slow. I'm 6% over and would get 10-12 if I could get the pulleys.
yellow rose
Overnight Sensation
Again, how much power do you make at idle? Or cruise? If you have heating issues in those conditions, it's not a shroud that will fix it. The shroud is used when the fan is too far from the radiator. That's all. It's not magic.
It also won't fix other issues like the water pump turning to slow.
AJ/FormS
68 Formua-S fastback clone 367/A833/GVod/3.55s
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OK to summarize;
You need a waterpump with an anti-cavitation plate, a hi-flo stat, a 7 blade all-steel , hi-attack angle fan like the one shown below, with a thermostatic clutch, and a lower hose that is guaranteed not to get sucked flat, adequate exhaust flow and fresh cold air into the carb.
(EDIT; I also severely restricted my bypass hose., but still run a heatercore.)
Now when properly installed, the pump can be underdriven a lil, and the engine idled down to 650.
Proper installation means the fan cannot pull air from the engine side of the rad, and the rad is sealed to the incoming air stream. No worries, the 7 blader, when the clutch kicks in, will push all the hot air out, no hood venting required. Well with a turbo, maybe not all the hot-air will leave,lol.
After you get this set-up, the temperature differential between the top of the rad and the bottom should be a minimum of 30*F, with the hood closed, and idling at a stop. If it isn't, then install a shroud.
This system has more than adequately cooled my aluminum headed NA 367 in every iteration it has seen, with cylinder pressure above 177psi in every case, and including the mighty 292/292/108 cam.... but see, I have TTI headers and full length dual 3"pipes, and a big ol' hole in my hood sealed to the carb, directing fresh cold air into her. This system works so good, I run a minimum coolant temp of 207*F and a 7psi cap.
I and others are telling you what works.
But if you are building boost at idle, all bets are off.
You are free to spend your money any way you want to.
Oh, BTW, My rad is an ancient model, I plucked from a 1973Dart with A/C. After I proved the system worked with 100% water, I eventually swapped to 50/50 ant-freeze; so I wouldn't have to drain the water every fall, cuz; you know, I was getting older, and finding those petcocks on a lowered car was getting to be a PITA. The system continued to function as it did with pure water.
Because that 7-blader/with thermostatic clutch, is freakishly heavy, I went with a HD 8-vane pump with its larger impeller shaft, and assumed to be, heavier-duty bearings. That was 2001, and it's still on that engine; from a time standpoint that pump is the cheapest pump I ever bought..
If you are hesitant to install a real fan,on account of some stoopid video you saw that said your fan will suck 35 horsepower at 7000 rpm, then give your head a shake. Firstly your T-clutch will not be powered up at 7000, and Secondly; even if it was, you got a turbo, and Thirdly; if you can spin the tires to 60 mph what the heck does it even matter?
Thanks to Oldmanmopar for this pic
You need a waterpump with an anti-cavitation plate, a hi-flo stat, a 7 blade all-steel , hi-attack angle fan like the one shown below, with a thermostatic clutch, and a lower hose that is guaranteed not to get sucked flat, adequate exhaust flow and fresh cold air into the carb.
(EDIT; I also severely restricted my bypass hose., but still run a heatercore.)
Now when properly installed, the pump can be underdriven a lil, and the engine idled down to 650.
Proper installation means the fan cannot pull air from the engine side of the rad, and the rad is sealed to the incoming air stream. No worries, the 7 blader, when the clutch kicks in, will push all the hot air out, no hood venting required. Well with a turbo, maybe not all the hot-air will leave,lol.
After you get this set-up, the temperature differential between the top of the rad and the bottom should be a minimum of 30*F, with the hood closed, and idling at a stop. If it isn't, then install a shroud.
This system has more than adequately cooled my aluminum headed NA 367 in every iteration it has seen, with cylinder pressure above 177psi in every case, and including the mighty 292/292/108 cam.... but see, I have TTI headers and full length dual 3"pipes, and a big ol' hole in my hood sealed to the carb, directing fresh cold air into her. This system works so good, I run a minimum coolant temp of 207*F and a 7psi cap.
I and others are telling you what works.
But if you are building boost at idle, all bets are off.
You are free to spend your money any way you want to.
Oh, BTW, My rad is an ancient model, I plucked from a 1973Dart with A/C. After I proved the system worked with 100% water, I eventually swapped to 50/50 ant-freeze; so I wouldn't have to drain the water every fall, cuz; you know, I was getting older, and finding those petcocks on a lowered car was getting to be a PITA. The system continued to function as it did with pure water.
Because that 7-blader/with thermostatic clutch, is freakishly heavy, I went with a HD 8-vane pump with its larger impeller shaft, and assumed to be, heavier-duty bearings. That was 2001, and it's still on that engine; from a time standpoint that pump is the cheapest pump I ever bought..
If you are hesitant to install a real fan,on account of some stoopid video you saw that said your fan will suck 35 horsepower at 7000 rpm, then give your head a shake. Firstly your T-clutch will not be powered up at 7000, and Secondly; even if it was, you got a turbo, and Thirdly; if you can spin the tires to 60 mph what the heck does it even matter?
Thanks to Oldmanmopar for this pic
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famous bob
mopar misfit
Ended up w/ the fan 1/2 and 1/2 out , aprox 1" from the 28x19 crossflow , a little closer on the bottom .
I`d buy a smaller water pump pulley in a heartbeat , "if" I could find one the same depth as my hemi type single belt pulleys ! It`s 1 to 1 now -------
mopower440
Well-Known Member
On the water pump deal, i read a comparison a guy did on like 10 different big block mopar water pumps. It was on a motorhome forum and the motorhome had a 440 in it. The pump that flowed the best at idle and low RPM was the factory 8 bladed pump..not the 6. That 8 blade flowed 15 GPM from idle to 1500 rpm i think or something like that and all the others only flowed 4-7 GPM from idle to 1500. Being i had the most trouble with it running hot at idle and low RPM's i switched out the factory 6 blade to the 8 blade along with the radiator and fan and like i said, this thing runs super cool now. Not saying the pump is what did it but probably had something to do with it.. I put the 440 source housing on but ended up leaving the new 440 source water pump in the box after seeing how badly it flowed on that test as i already was fighting the heating problem, so i bought the factory 8 blade instead.
yellow rose
Overnight Sensation
Yep. That's a problem...finding the correct pulleys. I know it's a PITA because I had to look for a long time to find some. For some reason, my car came with an early water pump and radiator in it. So I put it back to 1973 stuff and had to buy pulleys. What a PITA that was.
An old wives tale from a mopar performance recommendation. In the direct connection manual and the Mopar performance updated Manual. 1" hole in a plate. When my rad. tubes were blown up went down to a 5/8 and it did make a difference at idle with a CSR electric pump. My wifes tail felt the same.
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I had a 17 lb cap on that super charged truck. Blew the head gasket when we under drove the charger for a test. The pressure was so great all at once it destroyed the radiator and blew the heater hoses off. That little cap had no chance to relieve the instant pressure. But if you never had a failure and your radiator is good. That is not your problem than.
yellow rose
Overnight Sensation
The manual is wrong. I have to run a thermostat. If I don't, it won't get any temp in it.
Think about it. The longer the coolant stays in the block, the HOTTER it gets. If the radiator can't get rid of the heat, adding more heat only makes it worse.
Again, it's an ignorant old wives tale that coolant needs to stay in the radiator longer. The book is wrong.
Come to think of it, I can't think of a Chrysler book I have that says to keep the coolant in the radiator longer. It's just wrong and doesn't make sense. Just like multi pass radiators.
This is my experience with a 74 Plymouth fury 318. When I got this car it was a low mileage totally all factory set up with never anything done to it. The temp gauge always showed a little over Center. That just bothered the hell out of me. So I got the brain wave to change the T stat. I had the car on many long trips. It had a 195 t stat. I went to a 160. It got hit within 20 miles on the hiway Then I went to a 180, got hot in about 50 miles. Went back to the 195. Problem solved. Well there never really was a problem other than the 1 I created. Gauge was happy being over the Center. I wasn’t. I took the cluster out and bent the needle back. Now I’m happy. Kim
With all t stats it stayed cool around town and idling. Kim
Moroso Water Outlet Restrictor Kits 63440
My motor has no bypass. The coolant system was designed at a NASCAR shop. I do not need a stat that can fail or the washers.
Due the water leaving my block is restricted with a one inch hose. This prevents cavatating which causes steam pockets. I am using a one inch upper hose. No stat can create cavatating. you must restrict the flow if your radiator is to large or with a high flow pump.
But like always you seem to know everything. I would rather believe the experts then your misguided advice as always. Sometimes I think you just make up stories to cause conflict. There are time you are correct but not often
Like I said I went to a 5/8 washer to see if I can drop the cavitating more . I was alright with the one inch hose as recommended by a friend Modify Nascar shop foreman Tony Hirshcman. Spotter for Kyle bush. #18 who designed my cooling system for street and track racing.
I did not decide this application or make up a story as you. The experts did. Something you and I are not. But I am learning late in life. Something I can admit.
YOU MUST RESTRICT FLOW LEAVING THE MOTOR AND TRAVELING THROUGH THE RADIATOR IF YOUR RADIATOR CANNOT DO IT. Steam pockets can be caused at idle with a high flow electric pump.
Seams like they all agree with the old Mopar manuals. I believe the later manuals they assumed it should be known. from knowledge learned in the 70's. Almost 50 years ago.
famous bob
mopar misfit
I used to run a washer/plate in a hot 406sbc , after trying 3-4 diff. sizes , worked very well --------did take longer to warm up tho !
One warm up pass around the pits two when its cold and the rest of the day we were running the pump and fans to get it cool for the next round. One inch seams to work the best as per the Direct Connection 50 yr old manual.
I have seen guys use a ball and homemade die to hammer a taper in the hole. Face the protruding side toward the hose. Thermostats usually fail closed. The washer eliminates the chance of it happening and watering down the track and the rear tires on the big end..
I have two bottles on the car One recovery and one catch can hooked to the top of the recovery that is mounted in front of the tire under the fender. You can see the line going to the catch can through the existing hole for the battery tray with the rubber grommet installed .
On a NASCAR they blow the steam out of the drivers side hood to keep it off the rear tires especialy the left/outside tire. After every 1/4 mile pass we drain the catch can. You cannot do that on a 300-500 mile race, And dirt cars the water just makes the track tackier.
I don't drive my car in the winter and I don't have a heater core hooked up. I cover the outlets with the coil.
The defrosters still clear the windshield on the inside and the wipers on the outside for night racing. Or when I get excited and start breathing heavy.
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