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What is so special about the 289 HiPo fan over the standard 289 Ford factory 4 blade fan? Does each fan use the same spacer? If you had a Hipo fan, did it always come with the fan shroud?

Not building concours car, but just competed my 22GT style HiPo like 289 2 bolt main and will be installing it next weekend.
 

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The HiPo fan uses a different spacer and is a full time fan...no clutch. I believe it was done because the Ford engineers felt the HiPo engine needed extra cooling at all RPM’s and especially at higher RPM’s. I ran one on my K’ish 289 engine and now use it on my 289 race engine during Summer track events.
 

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The stock 4 blade fan is designed to be cheap to manufacture with a rpm ceiling of about 4k rpm. A basic no frills cheap fan. The K code motor will make more heat because it makes more power but the main thing is the K code is designed as a high rpm motor and needs a fan that won't fly apart or use excessive power at high rpm.
 

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The stock 4 blade fan is designed to be cheap to manufacture with a rpm ceiling of about 4k rpm. A basic no frills cheap fan. The K code motor will make more heat because it makes more power but the main thing is the K code is designed as a high rpm motor and needs a fan that won't fly apart or use excessive power at high rpm.
I agree with everything but the power use. A hipo fan is very rigid. It is going to pull more air, thus use more power than a more flexible fan (standard stamped steel fan) at high RPM.
 

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The HiPo fan uses a different spacer and is a full time fan...no clutch. I believe it was done because the Ford engineers felt the HiPo engine needed extra cooling at all RPM’s and especially at higher RPM’s. I ran one on my K’ish 289 engine and now use it on my 289 race engine during Summer track events.
65-66 Mustangs typically came without clutch fans. As I recall it was A/C cars in 66 where clutch fans started to be used. Before/other than that is was 4 or 5 blade fixed fans.
 

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The stock 4 blade fan is designed to be cheap to manufacture with a rpm ceiling of about 4k rpm. A basic no frills cheap fan. The K code motor will make more heat because it makes more power but the main thing is the K code is designed as a high rpm motor and needs a fan that won't fly apart or use excessive power at high rpm.
This is NOT a Ford Mustang fan but it is off a Ford. Same exact design as the Mustang "economy" unit.
Failure occurred at way under 4000 rpm.
The point here is that OLD is OLD..... with use, over time, metal gets fatigued. Don't let this happen to you.

736563
736564
 

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Sigh, more money to spend this winter. I’m redlining at 6400 with the original C code fan!
 

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65-66 Mustangs typically came without clutch fans. As I recall it was A/C cars in 66 where clutch fans started to be used. Before/other than that is was 4 or 5 blade fixed fans.
And that means the fan moves less air at lower rpm. Because there is no free lunch.
I agree with everything but the power use. A hipo fan is very rigid. It is going to pull more air, thus use more power than a more flexible fan (standard stamped steel fan) at high RPM.
The HiPo fan has smaller surface area but enhanced blade curvature. It was designed to be used with the shroud to avoid overheating . The fan spacers are different for the standard ( long spacer) and HiPo ( shorter spacer) to position the fan correctly for the shroud. The blades are made of aluminum to be lighter than a standard fan and it is precision balanced. There is a 5-7 hp difference ( dyno proven) gain with the hipo fan. I have done it.
A standard fan has stiffening ribs and is not as flexible as you imagine it to be.
Randy
 

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Discussion Starter #10
Done, repo HiPo fan and shroud for my 22GT HiPo style 2 bolt main 289 :). Non A/C car, but does have a C4. Thanks for everyones input!!!
 

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So should I be concerned that the repo HiPo fan is a Scott Drake part as it's usually awesome or crap with them? With the fan being $120 and the spacer being $50+ it's not an inexpensive deal.
 

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I believe there is only one source for the HiPo fan, If there is a balance issue it will take out the water pump bearing and the seal will leak. Many other fans do this as well. I check the fan/pump for wobble before I go drag racing.
The HiPo fan isn't bad at low speed because it has more blade curvature than a standard fan which is just slanted. Th fan actually cavitates at higher rpm pulling less air than a standard fan which results in the power gain. The idea is the car moving through the air doesn't really need a fan at all. Ford engineers were pretty smart.
 

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Which is why I can run my engine without a fan on cooler days at the track, but still need it on hot 90F+ days...primarily for taxying to and from the grid. On the track is stays right around 210-215 without the fan.
 

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The HiPo fan has smaller surface area but enhanced blade curvature. ...."
Randy
Bingo ! ( as usual Randy )

The pitch of the HiPo fan is dramatically different. That is secret behind the HiPo fan moving more air, a lot more air than any other fan of equal diameter, and more air than many larger diameter fans. I use to have some engineering white paper on 60's era automotive fans. The Ford HiPo fan was ranked #1 by a healthy margin.

The more aggressive pitch design is analogous to the better prop driven aircraft which have a variable propeller. These aircraft engines are usually ran at a constant RPM, and the propeller pitch is changed to increase or decrease air speed.

Z
 

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My 66 hipo has a 69 mustang radiator with a fan shroud and the original spacer. I run a lot of timing and its bored 60 over with an aod and big trans cooler plumbed thru the oem radiator, no ac, and a functional shelby hood scoop. In the summer if I was in stop and go traffic, the mechanical gauge would creep up from180 to over 200 or more depending, so, I took my hipo fan down off the wall and put it back on my car, removing a 6 blade aluminum speed shop type fan with curved rght triangle shaped blades. Low and behold, it stays below 190! Fan blade style does matter!! Very glad I switched back to that old school, unique looking 4 blade hipo fan.... :)
 

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A very informative thread! I thought the HiPo fan was just cool thing to say you had. I'll give it a try along with the proper spacer. I already use the shroud.
 

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Which is why I can run my engine without a fan on cooler days at the track, but still need it on hot 90F+ days...primarily for taxying to and from the grid. On the track is stays right around 210-215 without the fan.
What T/S do you run on those 90º+ days?
 

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I don’t. I use a 3/4” flow restrictor. I also don’t have a heater, heater hoses, or bypass hose.
K, Thanks! Am assuming yours is a track (road course) car?
 
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