“Duramax fan”

[Slade88]

Hi everyone I’ve been reading up on this forum about the different cooling fans available for our trucks. It’s been a mixed bag but it sounds like there’s a fan out there called a duramax fan, it has 9 blades, is this something I could find at a junk yard? And if so what engine/models. What is the best mechanical fan I can get for my truck? Electrical fans sound interesting but I’m not really a fan of cheap plasticky electrical things that have a much higher chance of breaking then a good ol metal mechanical fan, how much cooler woukd my 5.7 88 single cab run? I’d like to do some good cooling system upgrades before some major performance upgrades that will inevitably make my truck run much hotter

 

[Donald Mitchell]

This one is from a 6.0 fits perfect and the factory gauge shows 10 degree cooler. playingwithtbi may be able to help with the truck they came in.

 

[618 Syndicate]

@L31MaxExpress has got a ton of experience with different cooling setups.

 

[Erik the Awful]

The part number is in the file name of that picture. It's a GM 15-80739. Pulling that part number up in RockAuto shows:
CADILLAC ESCALADE 1999-2000
CHEVROLET C1500 PICKUP 1997-1999
CHEVROLET C1500 SUBURBAN 1997-1999
CHEVROLET C2500 PICKUP 1997-2000
CHEVROLET C2500 SUBURBAN 1997-1999
CHEVROLET C3500 PICKUP 1997-2000
CHEVROLET EXPRESS 1500 2007-2014
CHEVROLET EXPRESS 2500 2003-2020
CHEVROLET EXPRESS 3500 2003-2020
CHEVROLET EXPRESS 4500 2010-2019
CHEVROLET K1500 PICKUP 1997-1999
CHEVROLET K1500 SUBURBAN 1997-1999
CHEVROLET K2500 PICKUP 1997-2000
CHEVROLET K2500 SUBURBAN 1997-1999
CHEVROLET K3500 PICKUP 1997-2000
CHEVROLET TAHOE 1997-2000
GMC C1500 PICKUP 1997-1999
GMC C1500 SUBURBAN 1997-1999
GMC C2500 PICKUP 1997-2000
GMC C2500 SUBURBAN 1997-1999
GMC C3500 PICKUP 1997-2000
GMC K1500 PICKUP 1997-1999
GMC K1500 SUBURBAN 1997-1999
GMC K2500 PICKUP 1997-2000
GMC K2500 SUBURBAN 1997-1999
GMC K3500 1997-2000
GMC SAVANA 1500 2007-2014
GMC SAVANA 2500 2003-2020
GMC SAVANA 3500 2003-2020
GMC SAVANA 4500 2010-2019
GMC YUKON 1997-2000

Or you can just buy it from RockAuto for $41.

 

[PlayingWithTBI]

playingwithtbi may be able to help with the truck they came in.

This is what I got from a 1998 C1500 for my 88, works a lot better than the old 5 blade fan, cooler A/C too. Plus it's a lot quieter

You must be registered for see images attach

 

[PlayingWithTBI]

It's a GM 15-80379.

Maybe 15-80739?

 

[Erik the Awful]

Thanks, corrected. I fat-fingered it.

 

[Orpedcrow]

Maybe 15-80739?

And this fan blade bolts to the factory fan clutch in a 5.7? I’m thinking about going back a mechanical fan.

 

[Schurkey]

And this fan blade bolts to the factory fan clutch in a 5.7?

Not likely. That is, even if it bolts to the ordinary 5.7L fan clutch, it's likely to over-stress the clutch and cause problems.

I'd expect the "Duramax" fan to need the "Duramax" fan clutch, or one built similarly that happens to fit the 5.7L water pump.

Fans and clutches are something of a matched-set. A Heavy-duty or Severe-duty clutch shouldn't be used with a typical automotive fan because the fan doesn't provide enough drag to get the clutch to release; and the fully-engaged clutch may over-speed the fan. Similarly, a big fan on a light-duty clutch will have so much drag that the clutch is over-worked.

One wonders what rpm the Duramax fan is rated for; especially since the D-max isn't a high-rpm engine; and the pulley ratio of the 5.7 means the water pump is probably turning faster than the crankshaft rpm.

I’m thinking about going back a mechanical fan.

Overall, good idea.

 

[L31MaxExpress]

Duramax fan is similarly sized to the TBSS 6.0L fan. The fan bolt pattern is the same between the TBSS and Duramax. The 6.0L severe duty clutch threads on a Vortec water pump. Not sure what clutch someone would use to marry it to the TBIs 4 stud arrangement.