|09-23-2013 12:32 PM|
|eric32||Here is an update guys I just got back from my dad's house and I finally with his help got a real shroud on this thing. I could not use a clutch fan as it hit the radiator and it is forward as far as it can go even to the point we cut into the core support when we stuffed a v8 in it four years ago. Its only low 60's so I can not really test it yet too see if its enough but you can't get any better then this for a shroud setup as its from a s10 and had to just cut some here and there to make it work but man it pulls a lot more air then it used to and I am still having to use a flex fan but if this does not do it then next summer I will get a electric setup for it. Thanks guys.|
|07-22-2013 01:34 PM|
|eric32||I was going to go that route but I can't with the way my motor sits the fan comes above the radiator and even using a smaller 15 inch it still will be slightly above the top. I am going to hopefully enclose the bottom up some and re do the top section and I am also going to try to cut out some of the lower air dam to allow more air as my fan only is pulling air through the top half of the radiator and the bumper air dam on the bottom of the bumper covers the rest of the radiator. Going to try a few things and I will post back of what happens. Getting ready for a paint job too so will have hands full.|
|07-22-2013 09:42 AM|
The root problem is the lack of a shroud. The shroud must fit the perimiter of the radiator (at least the core) tightly. Then fair in the shape to just enclose the fan plus some engine movement space around the diameter. Without this type set up the only place the idleing engine's fan pulls air is just in front of the fan. This leaves half or more of the core with little to no air movement hence no heat transfer to the atmosphere. The shroud uses the fan to develop a low pressure area behind the entire core, therefore, there is air pulling through all the available cooling surface instead of half of it.
Clutch fans would make no difference in cooling, though are quieter at cruise where they are not needed so they clutch out and just coast with the air streaming past. Plus, there isn't any forward space for them in an S10/15 conversion. Electric fans suffer many of the same issues with a inability to configurationally cover the needed core area and take up too much space especially when properly mounted using some bracket method that doesn't use fastening the can to the core.
So keep the fan you have and either buy a decent shroud kit; examples:
Aluminum Fan Shroud, 28 W x 18.5 H - Speedway Motors, America's Oldest Speed Shop
A configuration that couldn be home fabricated and is very strong:
Google Image Result for http://www.cadtechindustries.com/Images/products/Offroad%20parts/radiator%20shroud.jpg
|07-22-2013 09:04 AM|
|eric32||That is a option but I would like to have the fan instead as I am not a big fan of electric fans. I will see how it goes with a different add on to what I already got then go from there. I can get a standard duty clutch fan from summit but from what I read they don't cool as good as a heavy duty or a severe duty clutch fan. I don't know if a standard duty one would be good enough or not.|
|07-21-2013 03:15 PM|
|07-21-2013 12:16 PM|
|eric32||Ok guys talked with my Dad over the weekend and the shroud I posted will not work with what I currently have so what we are going to do is close up the bottom as much as we can and see how it goes. Hopefully it will work but if I need to replace the flex fan with a clutch fan I have several issues. Where I live its hard to find anything less then mid 90's for vehicles at the local junkyards and my belt system is a v belt setup with a clockwise rotation fan and if I got a clutch fan from a local junk yard it will be a counter clockwise rotation fan and a serpentine setup. I just put a brand new water pump on and I don't want to have to change everything out just to run a counter clockwise rotation clutch fan. I want to run a heavy duty one but I don't know the first place to look and how to get the proper depth of a clutch fan. Any suggestions on where to start and what I should look for? I have never looked to buy one before. Hope some one can help me with some info.|
|07-20-2013 09:04 AM|
I found this make your own custom shroud kit at summit and I believe this will be what I need and should work wonders with my flex fan. I don't think I need a clutch fan just yet as tech said I need to get my shroud going first then test and see how this goes. Like I said it pulls a lot of air you can feel itpulling but as you seen the photos its needs a proper shroud like the oem's use. Thanks a lot guys I got a direction and what I need to do. Cheers all.
|07-16-2013 02:01 PM|
If you use any type of fan clutch on the water pump hub, you must use a factory fan that fits the fan clutch and the fan clutch bolt pattern. That is why fabricators use flex fans and fan spacers.
When I installed a 1970 Pontiac 455 engine in my '55 Chevy, I used a flex fan and spacer, no fan shroud. The 4-tube radiator came from a '68 Oldsmobile and the radiator shop sectioned the radiator tanks and core and neatly fitted it to the '55 Chevy radiator support. The engine ran 180* with a 180* thermostat in Texas summer heat with 4.10 rear gears on the highway at 4500 RPM.
|07-16-2013 01:29 PM|
|07-16-2013 12:57 PM|
When I changed from a 7-blade CCW rotation fan back to the OE 5-blade CCW rotation fan, I also replaced the thremo-fan clutch just because the OE clutch had 160,000 miles on it. Even with that many miles, the OE thermo fan clutch seemed to still be in good condition.
I installed a new AC Delco 15-4630 (GM-15709933), CCW rotation, thermo-controlled fan clutch. I purchased it from a seller on e-bay, NIB, for $60. It is still available from GM for $182 msrp.
LOL I did not know they still made those green fiberglass flex fans. A 1969 - 1970 Pontiac GTO with the Ram Air IV engine was equipped with a steel solid flex fan.
|07-16-2013 11:50 AM|
|joe_padavano||The number of fan blades alone does not determine how much air a given fan will move. Automakers will vary the number of blades, blade spacing, blade shape, and fan diameter based on available space and even things like noise reduction. A seven blade fan is probably quieter, not necessarily more efficient than a five blade. Fans are also optimized for a specific RPM range. This is like designing a propeller.|
|07-16-2013 10:45 AM|
|07-16-2013 09:49 AM|
I purchaced a severe duty fan clutch from auto zone around 90.00 as compared to gm I think around 250.00 with spring and viscous coupling I is for temp other is for rpm I use mine to pull a 33 camper and a car trailor so average around 6000-6500 lbs ,I cured my overheating problem ,only drawback I have if it is a problem for you it Does make more noise when it enguages a positive lock up and freewheels when not needed ,also it will spin when Cold until oil warms up then it works as designed ,,Works Great for me ,hope this helps
also you will need about an extra 1 in space between radiator and fan as it is thicker.
|07-16-2013 08:47 AM|
|eric32||I did some research and according to what I found there is a standard duty then heavy duty and then super duty clutches for a clutch fans. Now checking out summitracing they only have standard duty clutch fans and the best you can get is either a heavy duty or super duty clutch setup but since they don't have any heavy duty style clutch fans I don' know what to do about that. But I did find that summit also has aluminum shrouds that you can customize from a 15 inch to 19 inch fan and I might go that route first before changing out the fan at this point but I am going to make some big changed to what I got first and maybe cut some of it back and get a factory shroud set up to maybe fix it to clamp on my existing one and close up the bottom. I am getting ready to do a paint job next week so all that will be addressed. But thanks to you guys I do have some ideas. If I have to go to a clutch fan the thermo style is the way to go but they all have different temp ratings and I don't know what to get on that as I would like it to be fully engaged at idle if around 190 to 200. Like I said I never had one on truck before. I also would like it to be either a 5 or 6 blade heavy duty steel fan not a cheapo plastic one.|
|07-16-2013 06:14 AM|
Just by coincindence, a discussion about the used of a 5-blade fan in comparison with a 7-blade fan as used on a GM thremo-controlled clutch occurred the last Saturday in June at the monthly "Cars and Coffee" outdoor car show. The several Corvette owners at the gathering agreed that the 5-blade fans coolled better than the 7-blade fan on their Corvettes and they said they have tried them both. According to the Vette owners, GM put 5-blade thermo-controlled clutch fans on Corvettes, with or without A.C.
That prompted me to experiment and change a 1992-1995 7-blade steel fan and thermo-controlled clutch back to the original 1991 5-blade steel fan and thermo-controlled clutch on my 1991 S10 Blazer 4x4. I immediately saw a slight improvement in cooling but only at highway speed with no difference in traffic. GM used a 5-blade steel fan on S10 Blazers with RPO C60 A.C. through 1991. Starting in 1992 through 1995, GM used a 7-blade steel fan and starting in 1996, GM used a 11-blade plastic fan arrangement.
Either a 5-blade or a 7-blade fan was standard equipment with RPO C60 A.C. The RPO C42, without A.C., were equipped with 3-blade fans. My 1963 Pontiac Cantalina with a RPO Police and Ambulance option without A.C. was equipped with a 5-blade solid fan, and no fan shroud. The 1963 Pontiac with Police and Ambulance option, witout A.C., had a low fin count, 3-tube radiator for improved air flow at high speed. Only the 1963 pontiacs equipped with A.C. had a fan shroud and thermo-controlled fan clutch.
There is no definitive proof which number of blades and what type of fan is best under all driving conditions.
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