what fan blades to use/
udoittwo
Posted 2018-07-10 6:17 PM (#566430)
Subject: what fan blades to use/


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Although I have never boiled over with my 318, it does sometimes get fairly hot when sitting in a long traffic stop on a hot day. Towing my boat to Canada again this year in August I thought I might try a different fan. I am still running the 4 blade factory fan but I am wondering if it will run any cooler with a more aggressive fan. Will a 6 or 7 blade flex fan keep it any cooler? If it will help, what is a good fan option and what adapters might be needed?

Thanks again,
Karl.
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wizard
Posted 2018-07-11 2:13 AM (#566452 - in reply to #566430)
Subject: Re: what fan blades to use/



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Never use the flex fans as they are very consuming in horse Power.
Use a MoPar 5 or 7 blade fan with a fan clutch
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59 in Calif
Posted 2018-07-12 2:28 PM (#566517 - in reply to #566430)
Subject: Re: what fan blades to use/


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I don't see why a flex fan would require more HP to turn it, other than at idle RPM where it pulls the most air thru the rad. As the eng RPM raises, the blades flex into a somewhat neutral position. As the vehicle speed increases airflow thru the rad increases allowing the rad to do what it's suppoed to do. Personally, I prefer the clutch fan. But when I restored wife's 59 Dodge I didn't have the room for a clutch fan so I used the flex fan that came with the eng when it was in a motor home. I have not had any overheating issues. Jerry
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wizard
Posted 2018-07-12 3:12 PM (#566519 - in reply to #566430)
Subject: Re: what fan blades to use/



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Search for Engine Masters dyno test. The flex fans sucked the most horse power, followed by the oem 4 blade fan....
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udoittwo
Posted 2018-07-13 7:39 PM (#566565 - in reply to #566430)
Subject: RE: what fan blades to use/


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All right, "knock on wood" that I do not have ANY overheating issues in the future and, please know that I am NOT racing, so I don't really could care less IF I am losing HP in a hot day traffic jam. I simply would like to know, as I drive an old car with a factory 4 blade fan, no shroud, and that all cooling systems SEEMS to be working fine. What would be the best option, IF i get in another traffic jam for hours on a really hot day, that would make me think my car is doing OK and not about to boil over? Sorry, but I am just not racing in a traffic jam.

At THIS time, my only plan is to pull off to the side of the road, keep a plastic bottle with a large opening close at hand, have some craft brew and some snacks.

Basically, will a multi-blade fan[Chrysler or ANY] make any difference? How can I simply reduce the heat on a hot day with no free airflow?

Thanks again,
Karl
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wizard
Posted 2018-07-14 1:15 AM (#566574 - in reply to #566430)
Subject: Re: what fan blades to use/



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http://forwardlook.net/forums/forums/thread-view.asp?tid=21436&post... fan&highlightmode=1#M154551

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BigBlockMopar
Posted 2018-07-15 5:14 AM (#566624 - in reply to #566430)
Subject: Re: what fan blades to use/



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Aside from the 4-blade fan, running without a fanshroud is one of the main reasons for hot temps during idling.

Cars with engines that would most likely pull a load, like with airconditioning and such received factory fan-shrouds (although simple at first) and thermoclutch fans with 6/7 blades.
Any other (heavy) car will benefit too from this, although I don't see why a stationwagon didn't get a fanshroud as a standard option.


As for those 'flex fans', they indeed rob power to run from the engine, but as cooling fans are hardly necessary at highway speeds

And if you're (like most) running the ignition vacuum advance on ported (carb) vacuum, that's one more reason for a hot idling engine.
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udoittwo
Posted 2018-07-22 8:12 AM (#566997 - in reply to #566430)
Subject: RE: what fan blades to use/


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Looking for ideas on of how to pull a little more air through the rad. Car never had a shroud and again, it has never boiled over.
It just runs how when idling for long periods stuck in traffic when it is sunny and 90 degrees or more as any car will but maybe something simple to help it even the slightest?

I used to run an additive in my GTO. "BE COOL" os something like that and that actually helped a little. Maybe I try that.
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1960fury
Posted 2018-07-22 9:46 AM (#567005 - in reply to #566430)
Subject: Re: what fan blades to use/



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My car never had a fan-shroud either and it is entirely normal when the temperature rises in hot weather stop/go. Just use a good motor oil, not mineral oil. I use 5w-50 during summer months.
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udoittwo
Posted 2018-07-23 6:15 PM (#567095 - in reply to #566430)
Subject: RE: what fan blades to use/


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Yeah, it definitely runs hotter on hot days. I run full synthetics[10W-50] during the summer. I didn't notice any difference with the temps but the oil pressure held up much better when running full synthetics on really hot days in my black 67 GTO["great" car in the summer, I called in "my own private kiln"].

Guess I will just add some additives to the rad. and be happy. I haven't heard that they harm things and supposedly lubricate the coolant system and help to protect the seals.
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1960fury
Posted 2018-07-23 6:44 PM (#567097 - in reply to #566430)
Subject: Re: what fan blades to use/



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I personally don't like fan-shrouds, it makes servicing the engine more difficult and I like the idea of free flowing air at high speeds thru the radiator when cooling is needed most. Fan shrouds are somewhat restrictive and eat some horsepower too. I can get away without one in German summers. Things would be probably different living in the south.

Several years ago I installed a smaller aluminum radiator that cools better and weights 1/3 of the leaky OE one and uses less water too. The weight reduction is noticeable in fast curves. Only drawback, since it is smaller, its easy to get in contact with the rotating fan blades now when working on the engine. Fortunately I thinned and sharpened the blades so when I put accidently my fingers into it once, it was a memorable experience, so I will never do that again.
However to protect wires from the timing gun, etc, I put an aluminum cover over it (only the upper half). It looks like a shroud, but it isn't.
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Mopar1
Posted 2018-07-25 11:37 AM (#567165 - in reply to #566565)
Subject: RE: what fan blades to use/



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udoittwo - 2018-07-13 6:39 PM

please know that I am NOT racing, so I don't really could care less IF I am losing HP in a hot day traffic jam.
You may not be racing, but inefficient parts are reducing your MPG, even if it's not noticeable.
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Stroller
Posted 2018-10-20 1:00 PM (#572048 - in reply to #566430)
Subject: Re: what fan blades to use/


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Ok I know this is and old post. The shroud serves a purpose although arguable. Flex fans are garbage, period. They flatten out at high speeds. I have the original 4 blade fan for my '56 354 Fire Power hemi, but I put in a thermal clutch with a 6 blade fan. Runs nice an cool on hot july/august days sitting in traffic with the A/C on. Never goes above 190.
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