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.

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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.