Electric Fan Mods

[swathdiver]

Saw a recent post where some of the fellas were talking about more powerful fans and different bladed fans. So I did some digging through my manuals and came up with this for those interested:

Fan, Motor, 5.3/6.0 - 89023368
Fan, Motor, 6.2 - 5-Blade - Right - 20903475
Fan, Motor, 6.2 - 5-Blade - Left - 20903474
Fan, Motor, 6.2 - 9-Blade - Right - 15780796
Fan, Motor, 6.2 - 9-Blade - Left - 15780795
Fan, Motor, K5L - 700 Watt - 7-Blade Rimmed - Right - 15780796
Fan, Motor, K5L - 700 Watt - 9-Blade Rimmed - Left - 15780795

Fan, Blade Assembly, 5.3/6.0 - 7-Blade Rimmed - Right - 89024933
Fan, Blade Assembly, 5.3/6.0 - 5-Blade Rimmed - Left - 89023366
Fan, Blade Assembly, 6.2 - 5-Blade Rimless - Right - 20897350
Fan, Blade Assembly, 6.2 - 5-Blade Rimless - Left - 20897351
Fan, Blade Assembly, 6.2 - 7-Blade Rimmed - Right - 15780793
Fan, Blade Assembly, 6.2 - 9-Blade Rimmed - Left - 15780794

Fan, Shroud Assembly, 5.3/6.0 - 15780788
Fan, Shroud Assembly, 6.2, Cadillac/GMC - 5-Blade - 15780788
Fan, Shroud Assembly, 6.2, Cadillac/GMC - 9-Blade - 15780789

As for my truck, there's nothing to upgrade, it's a 5.3 with K5L, same as the 7 and 9 blade 6.2s.

It does seem that there is some inconsistent information though. Chime in and we'll update/correct.

 

[Doubeleive]

I bought these 2 motors
Fan, Motor, K5L - 700 Watt - 7-Blade Rimmed - Right - 15780796
Fan, Motor, K5L - 700 Watt - 9-Blade Rimmed - Left - 15780795
I am hoping they will fit the 5 blade fan's, I will hopefully find out this weekend

 

[swathdiver]

Wes, do we know why some Denalis have 5 blade fans while others have the 7s and 9s? Are your original motors (20903474/5) the 500 watt versions?

Well, if they don't fit you'll get a new shroud and fans but let's hope they do for the sake of simplicity and cost.

 

[Doubeleive]

Wes, do we know why some Denalis have 5 blade fans while others have the 7s and 9s? Are your original motors (20903474/5) the 500 watt versions?

Well, if they don't fit you'll get a new shroud and fans but let's hope they do for the sake of simplicity and cost.

I don't know other than it (appears) to have been a change starting in model year 2010+. I should be able verify the original motor part numbers when I get this pulled out
there could be a multitude of reasons such as cost reduction with less plastic, the re-design was satisfactory, all the way down to licensing of the blade design

 

[kbuskill]

So I guess hypothetically 2 700w motors with two 9 blade fans would be about as upgraded as you could get.

The ECM controls the power and duration the fans are on so in theory they would run less I would think.

 

[gpracer1]

I think it’s slightly more involved than that.
Motor rpms vs amount of blades vs pitch and design of blades all combined for a desired amount of airflow, plus shroud design if there are differences.

My guess would be more air flow at the engine coolant output side to the radiator.

 

[swathdiver]

Well, when mine kick into high gear they move a lot of air and are quite loud about it. Never lasts long though.

 

[Doubeleive]

ok, well the 700 watt motors for the 7/9 blade fan housings do not fit the 5 blade fan housings, also the left/right motors are different size and mount differently.
the 7/9 blade motors bolt up from the inside and 5 blade motors bolt up from the outside
the 7/9 blade fans are approx 1/2" bigger than the 5 blade fans
the 7/9 blade motors are heavier also
so overall I decided to go with bigger 7/9 blade system and put in the new motors there nice and quiet!

 

[swathdiver]

Quite a difference I'd say! I suspect that the main benefit will be in the duty cycle, they'll run less often and allow the drivetrain to work harder in hotter conditions. Same setup on the 2500s too. Probably good for the battery(s) as well!

 

[Doubeleive]

ya I already added the 1 3/8 radiator and a flexalite transmission cooler up front I think the only thing I could do to up it from here is a flexalite fan system, maybe if I lived in death valley, lol

 

[swathdiver]

Flexalite, now that name brings back some memories! Kept eating fan clutches on my '79 Buick so I ordered from JC Whitney a Black Magic electric fan. I was able to fit it within the old shroud. That thing moved some air! It came with a built in thermostat and dial to adjust when the fan kicked on and I also put in a manual switch to cool the motor off between runs at the track.

I think there's not much to improve upon with this setup, cost efficiently anyway.

 

[TM98]

ok, well the 700 watt motors for the 7/9 blade fan housings do not fit the 5 blade fan housings, also the left/right motors are different size and mount differently.
the 7/9 blade motors bolt up from the inside and 5 blade motors bolt up from the outside
the 7/9 blade fans are approx 1/2" bigger than the 5 blade fans
the 7/9 blade motors are heavier also
so overall I decided to go with bigger 7/9 blade system and put in the new motors there nice and quiet!

View attachment 193454 View attachment 193455 View attachment 193456

Where did you end up getting everything from?

 

[Doubeleive]

Where did you end up getting everything from?

I purchased a used fan housing off ebay which came out of a 2009 hummer with 200k on the clock but it was complete with motors and fans, I wasn't really to confident in the motors already having 200k on them so I purchased new motors from rockauto
normally if you buy the housing new it is only the housing and does not come with motors or fans
the housing is part #15780789
the fans are part #'s
ACDELCO 1580881 (15-80881) Radiator Fan Motor $ 45.79
ACDELCO 1580880 (15-80880) Radiator Fan Motor $ 63.79