Mounting electronic fans
 

I have a 2004 2500 8.1 Suburban that I am going to put electronic fans on. For those of you that have done this, how did you mount the fans? Do I need to fabricated a shroud or just drill a different hole and bolt them up? the 8.1 radiator is just under 38 inches and the factory fans are 34 inches so, obviously, the mounting holes do not match up .

have you tried to mount the OE fan shroud to the radiator support? holes might line up, and then you just have a small amount of exposed rad on either side.

I haven't really tried anything just yet. I took off the clutch fan and shroud and test fitted the fans and took some more accurate measurements. The mounting holes of the shroud do not line up with the fans. Now I am just looking for suggestions and advice. I thought about buying a new fan shroud and cutting it up to mount the e fans onto it, but a new shroud (upper and lower) is like 300 bucks at the local stealership which cost more than all the items for this little project combined.

the fans OE dont line up with the shroud. They mate with tabs on the lower rad support, and bolt in with threaded bosses at the top of the rad support. I have my 1500 with e fans and my neighbor has an 8.1 Sub I can try to compare for you tonight.

Take it from someone who is currently trying to cool an 8.1 with the 34" Tahoe fans and a GMT400 34" wide 454/8.1 core radiator, keep the mechanical fan. Pulling around my 1999 Tahoe my 420 hp marine cammed 8.1 struggles to stay running cool. My Tahoe also has the factory condenser pusher fan FWIW and it still runs hot. I am currently hunting for a factory big block or diesel fan shroud and will be putting a Duramax fan blade on a TBSS fan clutch on my 8.1.

I dunno, I made 477 at the wheels, pulled a car all the way to Vegas and back, in 100° F heat, highest we saw on coolant was 213, I backed out at 196 on the trans. This was on a 16mi climb, unlocked in third.

I have oe efans, aftermarket aluminum rad, oe engine cooler, external trans cooler. Without a load in winter I have to run the winter grill cover or she never gets past T stat temp on the highway.

OP; I still need to get a hold of my neighbor to measure for you. I think E fans will do what you need.

Now that will pull some air!

DEWFPO

P.S. TBSS ?

Trailblazer SS

TBSS = Trail Blazer SS

The 2007 Trailblazer 6.0L fan clutch has the same thread size as the water pump and the same bolt circle as the Duramax blade. Have had a Duramax fan blade and TBSS clutch on my L31 Express van for years.

Believe it or not that big massive fan actually helped my mileage compared to the stock stamped steel 5 blade fan that was always engaged because the Duramax fan could keep things cool while freewheeling with few exceptions. When I get stuck in bumper to bumper traffic with a trailer and the a/c blasting it kicks in momentarily when you accelerate but only engages maybe 15-30 seconds at a time as opposed to that little flyswatters near constant engagement. 42°F a/c temps are also very refreshing at idle compared to the 50-60°F the factory fan gave. I ran the factory HD Tow package fan from a 1999 Suburban for a while too which was alot better than the 5 blade steel fan but did not move nearly the air of the Duramax.

https://cimg0.ibsrv.net/gimg/www.per...04d48aeb88.jpg



https://cimg3.ibsrv.net/gimg/www.per...6669ef0bf0.jpg

Thank you all for the suggestions and replies. Do any of you have part numbers for the TBSS items? I may try that after the efans. I'm not overtly concerned about issues that may arise. I do this little projects between clinical rotations to defragment my mind. I stumbled upon an old thread by screen name Whipple 496 that seems to have pictures of a shroud he made for his efan conversion ; however, I am unable to get the pictures to display. If anyone knows how to get ahold of that guy, please do so.

If you decide to play around with it. The stock 8.1 fan may already have the larger bolt circle of the TBSS and Duramax. It may be a direct bolt on. I have not had one to compare.

I do however know the Duramax fan is much quieter just sitting there freewheeling 99% of the time than those E-fans are screaming and it is alot easier on your alternator. Not to mention at idle the CFM of the Duramax fan roughly equals the electric and above idle the Duramax fan moves a TON more air. Please excuse the noisy 1.7 full roller rockers.

Regarding the pictures. Here is the few that do still show up. I have copied and attached them here for you.

https://cimg6.ibsrv.net/gimg/www.per...ab7f96317f.jpg
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You can buy higher flowing fans that came with the max trailering package. Three6gmc did just that. See his Instagram post below.

The fans I purchased are Dorman part number 620-654 which is the replacement for the trucks with enhanced cooling (towing package)? They have the following specification per Dorman tech support. Hopefully they will cool appropriately; however, it's a mute point if I can't figure out how to mount them :( .
https://cimg7.ibsrv.net/gimg/www.per...3b74f062a3.png

[QUOTE=1FastBrick;5449564]Regarding the pictures. Here is the few that do still show up. I have copied and attached them here for you.
https://cimg8.ibsrv.net/gimg/www.per...51ba8d7eae.jpg

https://cimg0.ibsrv.net/gimg/www.per...9293e13b5e.jpg
Thank you for the pictures! It would appear that I need to construct this back/ mounting bracket. What material would you all recommend for this endeavor?

What a great and simple idea. Will any year Duramax blade work?

DEWFPO

I love simple when it comes to a daily driver or tow rig. The belt turns the water pump and the water pump drives the fan. Does not get much more complicated than that.

The A/C Delco part number listed on rock auto for the fan blade is 1580690.
Fits 2001-2005 Duramax engines in trucks and 2006-2010 Duramax vans.
Hayden 2851 should fit both the 30mm x 1.5 thread pitch of the water pump and the 3.81" bolt circle of the Duramax fan. The OEM clutch for the 8.1 will not bolt to the Duramax fan. 3.25" vs 3.81" bolt circle.

The fan and clutch change is 1/2 the cost of what the electric fan assembly is itself. That is ALOT of gas you could buy and put in the tank and the mechanical setup actually cools better than the electric in my experience.

Also my appolgies to the OP of this thread. I got off topic with the mechanical fan upgrade. I hope the electrics work out for you. Just wanted to throw the information out there before you put a lot of time, effort and money and ended up disappointed in the electric setup like I did when it failed to meet my needs.

Sounds like my first marriage! No apologies necessary, sir; the information you provided was quite valuable.

Hey, folks. Sorry to resurrect an old thread, but....

Any idea if the Duramax Fan + TBSS Clutch would work on a 6.0?

Many thanks for any thoughts.

I still like my factory electric fans and factory harness a/c nice and cold in traffic, engine temp. nice also. Again only use FACTORY parts, used parts are better than aftermarket parts IMO

https://cimg8.ibsrv.net/gimg/www.per...6373d9b850.png

Thanks for letting us know you still like your fan setup after all this time.

DEWFPO