I am in the middle of replacing my radiator and I noticed that my stock four bladed fan looks pretty wimpy. Since I have the radiator and shroud out anyway, I am thinking about replacing it with an aftermarket fan. I use the car as a daily driver and I want the four core 23” radiator that I am in the process of installing to be able to handle the 10 miles commute to work each way, usually doing 60-70mph on the freeway, with the occasional bumper-to-bumper traffic if I get caught on the roads during rush hour. While I am at it would it be worth adding a clutch as well? If so, any suggestions on brands or thermal vs. non-thermal? I don't want to go electric. It looks like I can get a Flex-a-lite clutch and Derale flex fan for under $100. Does this sound like money well spent? I am on a budget, but I don’t mind spending the money if the need is there and the upgrade makes sense.

What did you do to your engine, if anything that would require such a drastic change in the radiator and fan?. The Camaros were once upon a time daily drivers back in 67 to 69 and 99.9 percent of them never had an overheating prblem in their stock form.

Unless you need a new radiator becasue your old one leaks, or your car does overheat, why waste a couple of hundred dollars on a new one? If your old one is junk and you need to buy a new one, then by all means get the bigger one incase you plan future engine mods.

NEVER buy a flex fan unless you eventually want to replace a hood and all you hoses and belts. Most flex fans are junk and will eventually come apart. Stock GM multiblade fans move more air than the flex fans will and don't come apart quite as often. Yes they do eat up more HP than a flex fan, but that's why fan clutches were invented.

Flexalite 5255 Fan Clutch $29
FlexaLite 5718 18" Fan Blade $31.69

I installed the above like a few of the other guys on this board have and am very happy with it. Its quiet and a good solid solution! This is with a 4 core radiator.
http://69camaro.nextmill.net/pics_011304/fanclutch1.jpg

Whats going on Gun's? Yup, the 15/163 merge does suck.

Before I did a clutch upgrade, I used a Durale 18" stainless flex (or similar Summit PN G4918) for $30.00 and also installed the $5.95 'Brassworks' Flow cooler impeller disk to a new/stock TRW H2O pump. These were the best and cheapest upgrades, that netted the best results. I would hold out for the Durale unit, as I have never had any problem with this fan comming apart, even on the local left hand turn 'Sportsman' cars out at El Cajon.

When it came down to configuring a clutch set up, I did pretty much the same thing as Brian in the above post, with my brotheren Frogman's 67 Firechicken. It had a hot 455cid big block, bla bla bla...... The only difference was I use a Delco HD fan clutch with the same fan. With the above, the engine stayed at 180* to 190* in San Dog traffic, year round. Now he's in Tulsa OK and still hasnt seen anything over 195*.....which is perfect.

Some other things I did that helped:

I ran straight DI water.
A bottle or two of 'RedLine' Water Wetter.
Made sure the shroud was sealed to the radiator good and that there were no holes in it.
Sealed the radiator to the core support using high some 1/2" high temp foam (from Marshalls Industrial supply, down by the West gate on MiraMar).
Made sure the hood to core support seal was in good condition.
Used an 18 Stant radiator cap.
And used a 'Robertshaw' high performence 180* T-Stat.

I also used the flexalite nonthermal clutch and flexalite 6 blade fan, except I run a 17 inch fan.

Mark,
The radiator that came with my car (I just got it in October) began leaking about a month ago and has steadily gotten worse. My motor is stock for now but I went with the larger size because it is an easy drop in and you never know when the HP bug will bite, and like chicane sez, there are times you just can't get away from the traffic down here. I know the rep that flex fans used to have, but I have been hearing that the new Durale fans dont come apart, so I wanted to hear what you guys think.
Brian,
Nice setup. What size spacer are you using?
chicane,
Whats up bud? How's Lost Wages treating ya? I'll be spending Wedesday night in Nellis, I think. I have never heard of the flow cooler impeller disk. What the hell is it and where can I get one? :D
What are the pro/cons to thermal vs. non thermal clutches? The thermal ones seem like a no brainer to me, but am I missing something?

Keep in mind this flexalite 18" fan I run is not a FLEX FAN, it doesn't come apart or have safety issues. I am running a long stewart pump with NO SPACER! My previous setup was a 17" flex fan with 2" spacer, but the clutch makes up the distance, using a stock shroud which fits the 18" nicely with about 1/4" to spare which is fine with my energy suspension motor mounts.
I went with mechanical clutch, it runs 60% of whatever the engine is running at, which works well.

Vegas rocks man. No smog laws for the hot rod, cool gun laws (to include it being a 'right to issue CCW state' thank you very much), not to mention being single and working for the Company. What?....are you kiddin? Gotta love it. I take it your comin up here for a little "sand" action? Hey if you got some time, give me a buzz. Maybe there is a minute or two to kill a frosty one. Is your email address still the same? Anyway, drop me an E so I can throw you my number.

As for the H2O pump gizmo: Brass Works Flow Kooler (http://store.summitracing.com/product.asp?d=5&s=280&p=292&searchtype=ecat) from Summit. It comes with a new rear cover seal and all that. Quick and dirty install ta boot.

As for the spacer, you'll need one at whatever length that positions the center line of the blade, into the shroud. I think with a short H2O pump, I used a 3" spacer, when not running a clutch. Kinda how Brians install looks....blade half into the shroud, but without a clutch. With a clutch, I'd have to say your gonna need one between 1.3125" (actual available is 1.5") to a 2" spacer to put the fan in the same place.

Now on to the clutch, I used a Z/28 heavy duty unit that I got from the Delco distribution wharehouse in the MiraMar area. I think it was something like $65.00 or so. It is a thermal unit and is what I have used on all my Hi-Po (to include high street RPM) applications.

If you ever have to go to a dealer for anything, only deal with John Hine Pontiac, down in the valley. They are the GM wharehouse for San Dog......if anyone in San Dog had a part you were looking for, it would come from there to begin with.

Brian, thanks for the clarification on the fan. I'm looking at a Flex-a-lite clutch/fan combo similar to yours, although I am leaning towards the thermal clutch. Since I have the stock motor/body mounts on my 'vert, I might go with the 17" fan to ensure shroud clearance. I will have to do a trial fit before purchasing anything.
chicane, you've got mail.
Thanks again, TC! graemlins/beers.gif

GunnerV, if you can maximize the shroud diameter to the full 18" fan your cooling efficiency will be better at lower speeds. That said, if your engine runs smooth and when you throttle it it doesn't jump much in its engine mounts then you probably will be fine with an 18" fan.

I'll second that !!

I myself run solid mounts as of, well, forever.....but my 69 had poly mounts in it and it was a torquey little mouse, as is Frogmans Firechicken with the 455 and it didnt contact the shroud with the ole 18 incher in it....

I measured my shroud and I have at least 19" clearance so the 18" fan should fit. I just got my parts in the mail before I hit the road, so I should be able to get the radiator in this weekend. Thanks for all the help!

Brian, which shroud are you using on the 4 core rad.?

I am using the standard small block shroud, nothing special. I have a 2 Core Aluminum Radiator now, but this is the same shroud that did fit my 4 core radiator before. I run a Northern CR5072 aluminum radiator that is the same dimensions as stock and supports the stock shroud. Works great

I would steer clear of the cheap import imitation brands and stick with a well known brand like Flex-a-lite. Most of their products are rated for 10,000 rpms. I have honestly never talked with anyone that actually had an brandname, aftermarket fan problem, flexible or not, but have personally seen two factory fans come apart. One Chevy and one Ford. The Ford shot the blade right thru the drivers fender and stuck in a tree trunk. Both were older vehicles. Remember, the factory units are a moving part and are nearly forty years old.

sorry,double post.