need to cool down max wedge in traffic and stop lights

[biomedtechguy]

flex fans have a reputation of cracking and the the blade flies off putting a nice hole in your hood, radiator and hoses.

I'm 58 years old, been around cars since my early teens, and I've never heard of that before. I don't doubt that you and F4R/T (he agreed) have, but I haven't.
Maybe varying degrees of build quality and materials? I seem to remember some pretty flimsy ones to the touch from "back in the day" but I find it hard to believe that Derale would make a fan that would come apart.
FWIW here's what mine (I needed a thin one) on the Roadrunner looks like:

 

[coloradodave]

My experience with flex fans. Always ran Flex-A-lite (fiberglass) flex fans on my race cars. Very light and cooled fine for making rounds. Worked and raced out of a major California speed shop for many years and sold hundreds (yes, hundreds) of flex fans. Heard the stories, NEVER saw one come apart. Actually, a customer did bring one in to show us after it had an encounter with his radiator, which had come loose from its mounts.
Anybody have pictures of a fan through the hood? Your opinion may vary...

 

[MoparLeo]

I f we are going to do a "my dog is bigger than your dog " thing. I am 66 years old and have had 2 flex fan failures on 2 different cars. As said above both ended up destroying radiators and cutting the hoses and a belt. Stay stock or go electric. Flex fans were for racing not street cars. They are cheaper and lighter than factory but not nearly as durable. That is from my experiences. They don't go through the hood, not enough mass but they do put good dents in them. Pay your money, take your chances. Street parts must be a lot more durable than strip parts. Fact.

 

[biomedtechguy]

Thanks Mopar Leo, and it's always an honor to meet a fellow NRA member.
If I should happen to have a flex fan failure, I will be sure to post pictures in this forum, AND explain as best as I can what caused the failure. I read what your failed flex fans destroyed, but nothing, not even a guess, as to what caused the failure.
I "went electric" since the 3" of space I have now won't allow my factory clutch fan to fit. 3 fan motors later, a brand that ranks 4.9 out of 5 stars w/over 70 reviews, "it's the only brand I sell because they work so well and no problems" was what the retailer said, and the manufacturer claimed on one motor burned up (before my 3 in less than a week) and that was because the Ford Bronco had an alternator putting out more than 16 VDC.
My alternator passes muster w/the manufacturer of the fans as it always reads 14.73 VDC, I have all of the proper, recommended components in the circuit, and today I measured 0.44 V as my total voltage drop from source to fans. Fans, SPAL fans that have yet to burn up or fail. I would rather have my low profile flex fan than ANY electric fan as my primary cooling system radiator fan because I have my own chart of failure events, and so far it's electric fans 3, flex fans ZERO, and the 2 10" SPAL fans take up any "slack" quite nicely. Once I add a shroud, I will likely be able to reduce the parameters of when the electric fans kick in for backup, and it all fits.

 

[coloradodave]

I f we are going to do a "my dog is bigger than your dog " thing. I am 66 years old and have had 2 flex fan failures on 2 different cars. As said above both ended up destroying radiators and cutting the hoses and a belt. Stay stock or go electric. Flex fans were for racing not street cars. They are cheaper and lighter than factory but not nearly as durable. That is from my experiences. They don't go through the hood, not enough mass but they do put good dents in them. Pay your money, take your chances. Street parts must be a lot more durable than strip parts. Fact.

See? Here's another guy with lots of experience. Since I don't even remember 66, I'd say he's as qualified as I am to give an opinion with a lot of experience behind it...BTW, my current ride has twin electric puller fans. Who said anything about dogs?

 

[biomedtechguy]

Who said anything about dogs?

Right?

 

[RJRENTON]

Not to intrude but flex fans have a reputation of cracking and the the blade flies off putting a nice hole in your hood, radiator and hoses.

Not sure what the infatuation with flex fans is....both the aluminum or fiberglass blade design... is it strictly cost? They are significantly cheaper than the "tried and true" rigid design with either a torque drive or thermal drive clutch arrangement.....BUT...nothing is said about performance in terms of air movement (CFMs at some RPM level)....only "works great" or ???....nothing quantitative only a subjective thought..... how can effective performance, in terms of air flow at some RPM level, be compared to a "feeling" .....perhaps measuring effectiveness in terms of a drop in coolant temperatures at a repeatable condition (air temp entering the radiator) at a given speed to compare either the flex blade design (with and without a shroud) and a rigid blade design with clutch arrangement (with and without a shroud). Comments without some form of substantiation are only just an opinions....and we all know about opinions..... The other factor is flex fans have been known to fail unexpectedly....often catastrophically. I'm sure others will disagree.... Just my opinion of course.
BOB RENTON

 

[biomedtechguy]

My situation is simple. 3" total space on the Roadrunner. Already ruined the new Cold Case aluminum radiator in the GTO by putting a factory clutch fan into it, with about 1/2" of space when I installed it. I certainly wasn't expecting that to happen...I am using a full size blade flex fan on the GTO now.
On my Roadrunner, I only have enough room for the low profile flex fan. Without a shroud, it is not as efficient as I would like, but other than certain electric fans, I don't have a choice, and after 3 fan motor failures, I am not going to use ANY electric fan as my primary cooling fan. In conjunction with the appropriately timed activation of one or both of the 10" SPAL pusher fans, the flex fan and dual 10" fans have my temps running between 185-191. I am very happy with that range, and I expect a shroud will do any or some of the following: improve the cooling capabilities of the flex fan, which may reduce the parameters that determine when the electric fans operate.
It has been a frustrating and rather expensive journey, and it cost me several days of not being able to attend Cruisin the Coast, and that is treasure lost that I cannot recover.
So I am using what works, and once the shroud is on my car I'm done and happy with what will be a very effective cooling system barring any fan failures. With 3 fans and the primary fan being mechanical, I have more confidence than any other configuration that will fit the space I have available.

 

[RJRENTON]

My situation is simple. 3" total space on the Roadrunner. Already ruined the new Cold Case aluminum radiator in the GTO by putting a factory clutch fan into it, with about 1/2" of space when I installed it. I certainly wasn't expecting that to happen...I am using a full size blade flex fan on the GTO now.
On my Roadrunner, I only have enough room for the low profile flex fan. Without a shroud, it is not as efficient as I would like, but other than certain electric fans, I don't have a choice, and after 3 fan motor failures, I am not going to use ANY electric fan as my primary cooling fan. In conjunction with the appropriately timed activation of one or both of the 10" SPAL pusher fans, the flex fan and dual 10" fans have my temps running between 185-191. I am very happy with that range, and I expect a shroud will do any or some of the following: improve the cooling capabilities of the flex fan, which may reduce the parameters that determine when the electric fans operate.
It has been a frustrating and rather expensive journey, and it cost me several days of not being able to attend Cruisin the Coast, and that is treasure lost that I cannot recover.
So I am using what works, and once the shroud is on my car I'm done and happy with what will be a very effective cooling system barring any fan failures. With 3 fans and the primary fan being mechanical, I have more confidence than any other configuration that will fit the space I have available.

Out of curiosity, WHY did to need to change to the Cold Case Aluminum Radiator in your GTO? Pontiacs have always run a little hot but how much more? What is the godpel, not to exceed number...200° F, 220° F, how hot is too hot? I had a '70 LeMans convertible with factory A/C that the previous owner installed a new Pontiac water pump and listened to a "buddy", that told him to replace the drive sheave to make the pump turn slower and therefore last longer. It ran hot.... Pontiac only used one pump design on all their engines...the difference was in the pump's sheave diameter which was almost 3" smaller diameter, spinning the pump faster by the ratio of ~ 8.5" diameter / 11" diameter x RPM, resulting in no over heating in traffic with A/C on and 90° ambient, because the VELOCITY AND GPM of the circulated coolant was greater. Perhaps you could change the water pump sheave to that of an A/C car to achieve the benefit. Not all solutions to a hot running engine are solved by an aluminum radiator. Remember, the fins per inch and not the number of tubes, is the important factor as the fins are the heat transfer media. Personally, i believe electric fans are a panacea, but if significant engine modifications are involved, these changes would adversely affect the cooling systems performance. Re your electric fans failures, most of the time the motor has failed is due to an OVER LOAD condition trying to move more air flow at a higher static pressure than the motor can deliver. You would need to look at the fan's curve (static pressure vs CFMs) at a given impeller diameter and RPM to determine if the motor supplied is capable. Most of the electric fan suppliers seldom publish curves for their offerings....its up tp the purchaser to pick the fan, then make it work. I can appreciate your difficulties but I'll continue to use what was origionally supplied for my application.
BOB RENTON

 

[Cranky]

Well, I'll be 70 in May and have seen both flex fans and stock fans with cracked blades but so far, never one that came apart....and never had any of mine crack or fail....both flex and stock ones.

 

[biomedtechguy]

I'll continue to use what was origionally supplied for my application.

My "application" has morphed by choice to something far from the original design.
Why Cold Case?
My Roadrunner had a 26" radiator from some 1968 car and I have had it tick up in temperature on a long highway run, a couple of vertical cooling channels were rolled at the bottom, and being a V-Code, it never had Air Conditioning like it does now, and the Wraptor added power steering, a MUCH better looking AC compressor that the Vintage Air offering, a 140 amp alternator and the dang thing sure is pretty...
So lots of reasons for the Cold Case radiator in the Roadrunner.
As far as the Cold Case in the GTO, I found it running on the hot side and it also received a Wraptor and Vintage Air, so the Cold Case radiator provides a better radiator with the non-AC radiator cradle the GTO has.
The problem with the GTO I truly believe is the gap in the impeller vanes to the divider plate is larger than 1/10th inch, but until I remove/move a world of "stuff" to check and adjust that gap, I can only hope that's the problem, although I've addressed just about everything else.

 

[RJRENTON]

My "application" has morphed by choice to something far from the original design.
Why Cold Case?
My Roadrunner had a 26" radiator from some 1968 car and I have had it tick up in temperature on a long highway run, a couple of vertical cooling channels were rolled at the bottom, and being a V-Code, it never had Air Conditioning like it does now, and the Wraptor added power steering, a MUCH better looking AC compressor that the Vintage Air offering, a 140 amp alternator and the dang thing sure is pretty...
So lots of reasons for the Cold Case radiator in the Roadrunner.
As far as the Cold Case in the GTO, I found it running on the hot side and it also received a Wraptor and Vintage Air, so the Cold Case radiator provides a better radiator with the non-AC radiator cradle the GTO has.
The problem with the GTO I truly believe is the gap in the impeller vanes to the divider plate is larger than 1/10th inch, but until I remove/move a world of "stuff" to check and adjust that gap, I can only hope that's the problem, although I've addressed just about everything else.

Re your GTO, you mentioned it was "running on the hot side".....how hot? and how hot is too hot...quantitatively?? as determined by who? Just asking. My experience with the Pontiac engine, the water pump's divider plate is a stamping, usually a stainless steel component, and is not adjustable, with O-ring like sealing members that seals the back side of the divider plate to the block's coolant passages. If these O-rings have slipped (possibly split) during assembly, the impeller coolant flow will by pass back to the impeller "eye" reducing block circulation.....sort of a P-P arrangement.
Re your V code car, as far as your comment goes, "couple of vertical cooling channels were rolled at the bottom", don't know what that means? My RS23V0A****** GTX with 4.10 Dana 60 A833 4 speed, same cam, PS-PDB with aux PS cooler, origional #2998956 radiator with the #2806070 torque drive fan clutch and 7 blade fan with shroud and runs at 210° F at highway speeds on a 90 degree day and during the Woodward Avenue dream cruise in August without any difficulties.....sometimes temp creeps up to 220 degrees F....without the world coming to an end. The only real change to my car was to use the same water pump drive sheave as the 426" Hemi uses (approximately 1.5" smaller diameter) and a Flowkooler pump, for better volume and higher velocity and Dexcool at 50%. Not exactly sure or why the 180-190 degree temp became the not to exceed value...pethaps some cooling system vendor picked the number to sell radiators?
BOB RENTON

 

[RJRENTON]

My "application" has morphed by choice to something far from the original design.
Why Cold Case?
My Roadrunner had a 26" radiator from some 1968 car and I have had it tick up in temperature on a long highway run, a couple of vertical cooling channels were rolled at the bottom, and being a V-Code, it never had Air Conditioning like it does now, and the Wraptor added power steering, a MUCH better looking AC compressor that the Vintage Air offering, a 140 amp alternator and the dang thing sure is pretty...
So lots of reasons for the Cold Case radiator in the Roadrunner.
As far as the Cold Case in the GTO, I found it running on the hot side and it also received a Wraptor and Vintage Air, so the Cold Case radiator provides a better radiator with the non-AC radiator cradle the GTO has.
The problem with the GTO I truly believe is the gap in the impeller vanes to the divider plate is larger than 1/10th inch, but until I remove/move a world of "stuff" to check and adjust that gap, I can only hope that's the problem, although I've addressed just about everything else.

Have you considered APE, Ames Performance Engineering, for all your Pontiac parts both new and repro stuff...ive used them b4. They have all the various water pump, divider plate, pieces and parts....free catalogs etc.
[email protected]

Just a thought....
BOB RENTON

 

[biomedtechguy]

Not exactly sure or why the 180-190 degree temp

Because it's the range I am extremely happy about my engine operating within. Because I have a deposit on a BMP aluminum stroker that is going to have those same cooling system components to keep it cool, and I anticipate a 6XX HP and as close and wide a torque output of 700 ft lbs as can be reasonably achieved. I expect that may be a bit more challenging, so a baseline of the temps I have now hopefully will lend to an acceptable temperature range when the 541 cu in beast is generating heat as a byproduct of horsepower creation.

Re your GTO, you mentioned it was "running on the hot side".....how hot? and how hot is too hot...quantitatively?? as determined by who? Just asking. My experience with the Pontiac engine, the water pump's divider plate is a stamping, usually a stainless steel component, and is not adjustable, with O-ring like sealing members that seals the back side of the divider plate to the block's coolant passages.

It's malleable, and there's a 70 page thread on the Ames Performance Years forum that I have been active on for about 13 years. It deals mainly with the critical nature of the gap size between the water pump impeller vanes and the divider plate, with 1/10th inch being desirable.

Have you considered APE, Ames Performance Engineering, for all your Pontiac parts both new and repro stuff...ive used them b4.

We get their catalogs and have used them for a variety of parts. I appreciate the solid referral. The high volume, cast impeller (vs crappy stamped steel) in the aluminum bodied CVF water pump are all of the most favored designs, but I believe that the mechanic who installed that as part of the CVF Wraptor serpentine belt and accessories system failed to assure that the gap was in that 1/10th inch range, and all of the conditions that the temperature rises in are also indicative of that being a likely culprit. Regardless, and despite the labor intensity involved, I gots ta know...