Re: Can a hood scoop cause overheating?
[Re: ademon]
#1028692
07/09/11 11:20 AM
07/09/11 11:20 AM
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Joined: Jan 2003
Posts: 1,481
Outside
thedriver
pro stock
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pro stock
Joined: Jan 2003
Posts: 1,481
Outside
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Maybe. With the extra air you are running lean, thus running hot?
1973 challenger
Dana. 4 speed. Low deck.
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Re: Can a hood scoop cause overheating?
[Re: VITC_GTX]
#1028693
07/09/11 11:25 AM
07/09/11 11:25 AM
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Joined: Jan 2003
Posts: 28,067
Irving, TX
feets
Senior Management
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Senior Management
Joined: Jan 2003
Posts: 28,067
Irving, TX
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If it's not sealed to the air cleaner it can reduce the air drawn through the radiator a wee bit. It shouldn't make more pressure than the air moving through the grille.
Electric fans with shrouds? What kind of fans? Some of the cheapies (and not so cheapies) don't flow enough air to keep up with highway speeds.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind.
- Stu Harmon
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Re: Can a hood scoop cause overheating?
[Re: feets]
#1028695
07/09/11 01:32 PM
07/09/11 01:32 PM
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Joined: Mar 2003
Posts: 4,923
Tri-Cities, Washington
VITC_GTX
OP
master
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OP
master
Joined: Mar 2003
Posts: 4,923
Tri-Cities, Washington
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Quote:
If it's not sealed to the air cleaner it can reduce the air drawn through the radiator a wee bit. It shouldn't make more pressure than the air moving through the grille.
Electric fans with shrouds? What kind of fans? Some of the cheapies (and not so cheapies) don't flow enough air to keep up with highway speeds.
Unfortunately I don't know what kind of fans they are. I bought the system here from a Moparts member. I would think I wouldn't even need the fans at highway speeds. When I turn them off the temp doesn't change (on the highway).
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Re: Can a hood scoop cause overheating?
[Re: VITC_GTX]
#1028696
07/09/11 01:43 PM
07/09/11 01:43 PM
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Joined: Jan 2003
Posts: 25,200
Upper Midwest
MoparforLife
Too Many Posts
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Too Many Posts
Joined: Jan 2003
Posts: 25,200
Upper Midwest
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Quote:
Quote:
If it's not sealed to the air cleaner it can reduce the air drawn through the radiator a wee bit. It shouldn't make more pressure than the air moving through the grille.
Electric fans with shrouds? What kind of fans? Some of the cheapies (and not so cheapies) don't flow enough air to keep up with highway speeds.
Unfortunately I don't know what kind of fans they are. I bought the system here from a Moparts member. I would think I wouldn't even need the fans at highway speeds. When I turn them off the temp doesn't change (on the highway).
You are right in most cases you would not need a fan a highway speed as the forced air is plenty but in this case the fans may be blocking the flow at highway speeds. Adequate air flow at hiway speed may also depend a lot on the RPM's turned at said speeds.
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Re: Can a hood scoop cause overheating?
[Re: VITC_GTX]
#1028697
07/09/11 04:56 PM
07/09/11 04:56 PM
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Joined: Jul 2010
Posts: 1,719
Up North eh'
Stroked_Hemi
top fuel
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top fuel
Joined: Jul 2010
Posts: 1,719
Up North eh'
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I'm going to lean towards what feets is asking about, the fans and rad setup.
Typically when it comes to aero, if the hood scoop is not sealed, it will help cool the engine, because the air coming in will pass around the engine, exhaust manifolds / headers, etc.. and go under the car, yet this results in a handling disadvantage since this will promote front end lift at high speed.
Good luck,
Mike
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Re: Can a hood scoop cause overheating?
[Re: Stroked_Hemi]
#1028698
07/09/11 06:18 PM
07/09/11 06:18 PM
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Joined: Jan 2003
Posts: 28,067
Irving, TX
feets
Senior Management
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Senior Management
Joined: Jan 2003
Posts: 28,067
Irving, TX
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Quote:
I'm going to lean towards what feets is asking about, the fans and rad setup.
Typically when it comes to aero, if the hood scoop is not sealed, it will help cool the engine, because the air coming in will pass around the engine, exhaust manifolds / headers, etc.. and go under the car, yet this results in a handling disadvantage since this will promote front end lift at high speed.
Yes and no.
Vehicles at speed create low pressure areas behind the radiator. The radiator is an obstruction to air flow. Therefore, it has higher pressure in front than behind.
Chin spoilers and under covers increase this low pressure effect and actually help draw more air through the radiator.
Hood scoops that do not seal to the air cleaner or carburetor force air into the engine compartment and greatly reduce the low pressure area behind the radiator. That kills the additional suction behind the radiator.
Sealing the radiator to the grille so air can't get around it slightly increases the air flow. The problem is the air will only stack up a wee bit before venting around the grille opening and over the hood.
Air is a funny thing. It flows like a liquid but can be easily compressed.
I'd like to see the fans and shroud on this car. If it's one of those flat faced square cornered "pretty" aluminum fan shrouds it needs to go in the trash.
It might be possible to "save" some of those by making some flappy cutouts in the flat parts of the shroud. They open towards the engine to allow air trapped by the shroud to escape. At low (or no) speed the fan draws them closed and pulls more air through the radiator.
Look at this factory style Viper fan and you can see how much air the engineers wanted to vent out of the shroud.
We are brothers and sisters doing time on the planet for better or worse. I'll take the better, if you don't mind.
- Stu Harmon
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Re: Can a hood scoop cause overheating?
[Re: feets]
#1028699
07/09/11 07:01 PM
07/09/11 07:01 PM
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Joined: Jul 2010
Posts: 1,719
Up North eh'
Stroked_Hemi
top fuel
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top fuel
Joined: Jul 2010
Posts: 1,719
Up North eh'
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This discussion can surely get complex, but for the old Demon having a hood scoop which isn't sealed, it will surely keep the engine cooler, even going back to the old Hemi Super Stock Barracudas and Darts, some would find that it was better to run without the plate that seals the carbs to the hood because the cooling benefit would outweigh the ram air effect for performance on the drag strip.
Edit.. removed my excessive babbling..
Cheers,
Mike
Last edited by Stroked_Hemi; 07/10/11 01:04 PM.
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Re: Can a hood scoop cause overheating?
[Re: VITC_GTX]
#1028700
07/09/11 09:34 PM
07/09/11 09:34 PM
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Joined: Jan 2003
Posts: 4,213
Williamsport PA North Central ...
13ChargerR/T AWD
master
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master
Joined: Jan 2003
Posts: 4,213
Williamsport PA North Central ...
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Ive got the OPPOSITE problem it will get into the 200's in town/traffic/stop and go with not a ton of air flow but cools right down to 175-180(180 thermo) on the road. ive got a 6 pack scoop a Eddie 750 and its a 340 engine with stock cam and im guessing 8.5 compression. its a stock radiator with a typical 340 fan(no clutch fan just a "regular" one) and its got the shroud in place. Also not a sealed unit(obviously by picture)
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Re: Can a hood scoop cause overheating?
[Re: feets]
#1028704
07/10/11 06:35 PM
07/10/11 06:35 PM
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Joined: Feb 2003
Posts: 607
NY
old340dog
mopar
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mopar
Joined: Feb 2003
Posts: 607
NY
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I opened up my hood scoop when we did my motor rebuild in my duster 340. Since the hood was off I figured it would be a good time. I seem to run around 200 on the highway. But have had some issues with getting the carb mix right. This topic has praised some questions and issues I have wondered in regards to air/fuel mxture. One thing I have had on mine is a K and N extreme air cleaner lid and air cleaner. I changed it yesterday,and took the car out for a run. To me it seemed like the car ran a little better and was a little more responsive.Since I didn't have so much air coming into engine bay.  But what do I know.
old340dog
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Re: Can a hood scoop cause overheating?
[Re: Mopar_Country]
#1028708
07/10/11 11:48 PM
07/10/11 11:48 PM
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Joined: Oct 2004
Posts: 601
Clintwood VA
johnedod
mopar
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mopar
Joined: Oct 2004
Posts: 601
Clintwood VA
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I have an open 6 pack scooped hood on my 68 road runner. Mine didn't run hot with the stock hood and it doesn't run hot now either. My scoop isn't sealed to the breather. No radiator weatherstrip at the front of the hood or cowl weatherstrip at the rear. for what it's worth.
Johnedod
68 Road Runner
71 Road Runner
78 Power Wagon
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