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5 blade to a 7 blade well it help

pedal2themetal

pedal2themetal

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HI,
Since the cam change I'm having a over warming condition over halfway on the stock gauge It used to run less than half way .. Well going from the 5 blade fan to a 7 blade help in keeping it cooler. Radiator has been cleaned
 
Do you have a shroud? Also have you checked your fan clutch for resistance? A free spinning fan clutch is not going to cool. If it has some resistance it should be good to go.
 
HI,
No clutch on the fan and no shroud? I don't remember if it came with one when I rebuilt it like 6years ago.. If it had one I'm sure I would have installed it back on...
 
pedal2themetal said:
HI,
No clutch on the fan and no shroud? I don't remember if it came with one when I rebuilt it like 6years ago.. If it had one I'm sure I would have installed it back on...
Click to expand...
If it was an A/C car it would have a shroud.
 
HI
NO AC. So no shroud then..
As for timing. Not sure? I'll put an light on it tomorrow . When I installed the cam I timed it by vacuum .. got max vacuum and backed it off 2 ".. It runs real strong no missing or pinging at WOT to shift point. its running about 16"vacuum.
 
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pedal2themetal said:
HI
NO AC. So no shroud then..
As for timing. Not sure? I'll put an light on it tomorrow . When I installed the cam I timed it by vacuum .. got max vacuum and backed it off 2 LB.. It runs real strong no missing or pinging at WOT to shift point. its running about 16#vacuum.
Click to expand...
It still most likely had a shroud. Just a/c cars all seemed to have them.
 
HI,
OK I bought it used so I'm not sure if it had one or not.. I've owned it for almost 10 years got almost 50T on the rebuild, it just had a bad timing gear (plastic factory junk) but I rebuilt it anyway.. It only has 92,000 on the meter.. When I rebuilt there was NO junk or goop in the heads or corners of the valley very clean motor..
 
Fan shroud and Flowkooler water pump & hi flow thermostat should make a big difference.
 
HI,
Tho I appreciate all the reply's.. No one has answered my original question..
Well a switch from a 5 blade to a 7 blade fan help in cooling?? Well it move more air?
 
PurpleBeeper said:
Really? It’s hard to image that if the fans spin at the same rpm & the blades are at the same angle. Where did you see that information?
Click to expand...
More blades increase airflow resistance. I won't get into a renton-esque explanation, but fewer blades have less airflow resistance. Very simply, when a blade pulls air what takes up the space behind it ? More air or another fan blade blocking the air ? Look around the house, you'll see most fans with 3 or 5 blades.
 
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WileE said:
More blades increase airflow resistance. I won't get into a renton-esque explanation, but fewer blades have less airflow resistance. Very simply, when a blade pulls air what takes up the space behind it ? More air or another fan blade blocking the air ? Look around the house, you'll see most fans with 3 or 5 blades.
Click to expand...
Please give the scientific explanation. I understand that at the extremes, flow won’t be good….e.g. a 1-blade fan or a 1000-blade fan won’t flow well. I just went from a 6-blade to a 7-blade and saw a 5-degree lowere running temperature about 1 hr apart (before/after) and the 7-blade runs cooler
 
my experience is that it depends on the fan blade design (blade pitch, offset angles, etc). If you're comparing exact same designs and the only difference is blade count, then it's easier to compare. Different designs, it depends...for example, the Mopar viscous 5-blade moves a ton of air and it has 1 offset blade. I run an original steel 7 blade with a shroud and Flowkooler water pump and no complaints.
 
The concept that a 5 blade fan moves more air than a 7 blade makes no sense especially when you have seen fans on pickup trucks that appear to be fitted with 8 blades. A truck engine is used to tow and haul, two things that will overheat an engine if it isn't moving a lot of air.
 
Kern Dog said:
The concept that a 5 blade fan moves more air than a 7 blade makes no sense especially when you have seen fans on pickup trucks that appear to be fitted with 8 blades. A truck engine is used to tow and haul, two things that will overheat an engine if it isn't moving a lot of air.
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Then why don't prop planes have 7 blades, instead of 3 or 5 ?
 
PurpleBeeper said:
Please give the scientific explanation. I understand that at the extremes, flow won’t be good….e.g. a 1-blade fan or a 1000-blade fan won’t flow well. I just went from a 6-blade to a 7-blade and saw a 5-degree lowere running temperature about 1 hr apart (before/after) and the 7-blade runs cooler
Click to expand...
I shun getting into techno-speak, since I've observed it only causes irritating comments and disparaging replies. Just my opinion... of course. All I can say is... look it up.
 
WileE said:
Then why don't prop planes have 7 blades, instead of 3 or 5 ?
Click to expand...
Oh yeah, car radiators and planes are the same thing. How silly of me to think of automotive applications on a car forum.
 
I have no technical info on a 5 or 7 blade fan. However, my 65 Sport Fury (non AC car) had a 4 blade fan with no shroud from the factory. I mounted a piece of window screen in front of the radiator to keep the bugs out. It caused my engine temps to rise to the point of almost boiling at an idle.
I swapped the 4 blade for a shroud and thermo 7 blade fan and now the car can idle all day and not overheat. That said, I can't say that swapping a 5 blade for a 7 blade will help but from my experience, the combo of shroud and 7 blade thermo fan will bring your temps down.
 
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