[DaleO]

Originally Posted by lust4speed

I haven't told the story here, but did have that catastrophic accident with a Mark VIII fan when it came loose during testing and my hand was literally eaten by the blades. Had to have three fingers put back together and back on the hand, and spent a week in the hospital. While the event seemed like an explosion, the fan cut through my fingers about every inch until the blades were gone. The fan went into my hand from the radiator side and pulled it in, and neither the fan nor I faired that well. I was very fortunate that one of the best hand surgeons possibly in the world was on duty that evening and he took on the challenge with his surgical team. It was his first night back at the hospital after a three week speaking tour. The emergency room doctor had already told me that they would just clean up the hand and amputate the fingers back to good flesh and bone. Just after he told me that, a couple of young doctors came in and said they were looking for a challenge for their surgical team, and I was definitely it.

The fan blade still hangs over my workbench as a reminder to try and not be a dumbass. It's been a little over 10 years and the arthritis is settling in like they warned me, but I have full use of the fingers. Dropped a lot of nuts and bolts for the first two years but surprisingly have almost full feeling in the fingers now. The X-ray was taken just after we walked into emergency and we had gathered up parts and wrapped them up with the hand in a not-so-sanitary towel, and they just took the X-ray through the wrapped up towel.

uggh, that's awful, thanks for a cautionary reminder.

[Squidward]

Well, thought I would try the route of the Dorman 620-118.

I bought off Amazon so I could have favorable returns. Sure enough, I tried to install the fan behind my radiator, and it wouldn't clear the pump snout. I did some measuring, and if I were to trim the fan shroud to the tiniest clearance between fan and core, I MIGHT just barely clear the fan motor to the water pump snout. This is with a long nose pump. There is a small gap, maybe 1/2 to 3/4", between the rad support opening and the core. This would mean I would have to rework brackets for the radiator, AND radically trim the efan shroud.

Fan is being boxed up and sent back. So the Lincoln Mark 8-ish fan is too thick for a 1st gen.

[RocktimusPryme]

How deep is the Lincoln fan? I would have thought anywhere that could get a clutch fan could get one of the electric fans.

[GOAT8U2]

I have this dual on my GTO, don't need 1 big one anymore.

https://a.co/d/fkWjTyZ

This is a copy of the Ramcharger fans from years ago I believe.

[grivera]

Originally Posted by Squidward

This is with a long nose pump. There is a small gap…

…So the Lincoln Mark 8-ish fan is too thick for a 1st gen.

Since the first gen birds come with 4” (short) water pumps, would the OEM set up allow clearance for the fan?

[JLMounce]

Originally Posted by GOAT8U2

I have this dual on my GTO, don't need 1 big one anymore.

https://a.co/d/fkWjTyZ

This is a copy of the Ramcharger fans from years ago I believe.

This is far too big for a first gen F-body. The core on these things is only 23" wide, and end tank to end tank is in the neighborhood of 28".

Originally Posted by grivera

Since the first gen birds come with 4” (short) water pumps, would the OEM set up allow clearance for the fan?

I would think so. I have the short water pump and use a Flex-A-Lite Black Magic fan. It's fairly deep and I have about 2" of room to the waterpump pully.

[Sirrotica]

Yesterday I watched an episode of Matts Off Road Recovery (southern Utah) where he was going over his fleet of vehicles and touching on their shortcomings. When it came to his XJ jeep with a inline 6 in it he talked about the fan and the hood louvers. He said that he had tried every electric fan that was highly touted as the answer to a changeover from mechanical to electric, Including the Ford/Lincoln fans that everyone talks up.

He said all the electric fans failed in that application and he kept going back to the mechanical fan for his XJ with A/C. He said no matter the ambient temp he never has to stop and let the vehicle cool down with a mechanical fan like he did when testing the electric fans. I thought it was a good apples to apples test under extreme conditions that in his application he had never been able to use an electric fan without the vehicle overheating. When he switched back to mechanical fans the problem was non existent.

He issued a $10,000 challenge that if anyone had an electric setup that could cool in southern Utah and they could prove it didn't overheat, he'd give them $10,000. Putting his money where his mouth is........

Just for an observation, I've never seen any closed course race cars with electric fans used to cool them, always mechanical fans. i did see one autocross car many years ago with an electric fan that failed miserably after only a lap around the course.

Probably a little known trick to cool oval track cars down during a red/yellow flag was a water reservoir using a washer pump to squirt water over the core of the radiator while bringing the RPM up, works very well under extreme conditions. The water and air mixture together, will pull a lot more heat from the core than just air will.

[RocktimusPryme]

Originally Posted by Sirrotica

He said no matter the ambient temp he never has to stop and let the vehicle cool down with a mechanical fan like he did when testing the electric fans.

I think this guy is having the opposite problem that nearly all of us have with the under-radiated 60s cars. Unless I am reading it wrong its not really an apt comparison.

I also never have to stop to cool down....I have to start moving to cool down. Its the stopping that's the problem. And that's where an electric fan would benefit me. I don't think anyone would make the argument that a big mechanical fan wont move more air under RPM, including racing like you said. The problem is getting stuck in traffic, or a drive-through etc. I need more air at idle.

My car is pretty well sorted out, Cold Case, big 19" clutch fan with a modded clutch to engage faster (I could probably bend it a little more even). And its fine, but it creeps enough at idle that the thought of getting stuck in a bad traffic jam scares me. And its hard to keep temp down in the staging lanes unless.

Plus I have the Terminator installed and Im not making use of its fan controls, which activates my personal flavor of autism and annoys me. Ive just always had something more important to spend money and time on than moving this one to electric.

[JLMounce]

There's a reason the 2nd gen f-body has a much larger radiator than the first gen. There's simply not enough frontal area on a first gen factory sized radiator.

Big tubes and additional cores only get you so far. After the air passes through the first set of tubes and fins, most of the cooling that can be done already has. Each subsequent core of tubes and fins is dramatically less efficient as the delta between the air temp an water temp decreases.

This is why you see modern radiators thin with large amount of frontal area. It simply cools better. Of course it helps the modern EFI systems can rotate idle and skip cylinders here and there.

If I was to go back 10-15 years and catalog all of the threads on this forum discussing cooling issues, I would lay odds that the majority of them revolve around first gen F-bodys and early A-bodies. Both notoriously under radiated.

The rads are so small, that with anything much over stock power, you need massive CFM at idle to keep them cool.

My setup works okay. It used to cool fine at idle with my old engine, but I added quite a bit of power with the new engine. Now in temps about 80 degrees it will creep ever so slightly at idle. The fan is rated at 3300 cfm and I've taken pains to make sure the shroud is sealed as tightly to the core as possible and have also taken steps to reduce the amount of underhood air that can circulate back in front of the core between the radiator and the core support. This is actually my only complaint with the Cold Case radiator. The factory AC rad I took out of the car sat up against the core support with about 1/4" of room. The Cold Case has about an inch and a half of room between it and the core support, allowing hot underhood air to circulate in front of the radiator.

[Sirrotica]

First if all if the video wasn't applicable, I would haven't posted about it.

He's driving his XJ on the road, stop and go traffic to pull out stuck vehicles that he lets the engine idle while they're hooking up ropes or winches. All the time isn't running at elevated speed. How much air is passing through the radiator while winching a vehicle out of a ravine that isn't pulled by the fan, I can answer that, zero.

If you're unfamiliar with XJ jeeps the core support has the exact same problem as a first gen F body has, a small opening in the core support that is limited in how much radiator can face forward. He also cut louvers in 2 places in the hood to have less restrictions to exhaust the heated air from under the hood.

What speed is he traveling while rock crawling up embankments? No help from the air being pushed through the grill by vehicle speed.

I guess you'd actually have to watch his recoveries to see how much idling, and being driven at a crawl off road that is done before making a call that I don't understand the problem.

To add to this southern Utah ambient air temps during the summer hover from the 90s to well above 100 degrees much of the time.

BTW, closed course cars do plenty of idling in the pits as well as when they're is a red/yellow flag to re-align the running order before restarting a race. The point is as JL Mounce has stressed, fin area can only exchange so much heat at a given air speed.

Pointed out here already is the best electric fan loses at least 15% air volume over a mechanical fan, that's a fact that you can't overlook if your setup is already marginal.

I realize that you probably haven't spent a lot of time around construction sites, or HD trucks, but none of them use electric fans, all mechanical as well as large radiators. You can't cheat physics and if your system is under designed with little margin for say scale in radiators. or dirt on the fins, you're likely to run over that invisible line, and end up on the wrong side of it, at least occasionally.

After many years of running these cars on the street as well as racing them. I have the knowledge to know what works, as well as what doesn't. Electric fans will not be as efficient as an mechanical fan will for the energy expended.

There is a point that the alternator won't run the fan as fast as what is needed to transfer heat at the worst possible cooling conditions. My 05 GTO has electric fans, but it also is 364 Cu in aluminum block, with a huge aluminum radiator, it still likely wouldn't cool a 455 Stratosteak engine under adverse conditions.

The first gen F body was a chevy design and likely was intended to have enough cooling capacity for a 350 SBC. Add 50 to 105 more inches of engine to cool and you're going to run into a problem, especially at high ambient temperatures, Add A/c and you compound the problem even further. With an automatic transmission you further load the radiator. Stacking auxiliary radiators such as A/C and transmission coolers further dilutes how much heat can be dissipated from the cooling system.

I believe I have a very good grasp on thermodynamics applied to all vehicles, both from a classroom point, as well as a hands on learn the hard and expensive ways of what will cool a problem child vehicle. If you feel my post have little to no merit that's fine, just ignore my post. I was just trying to give some feedback from practical knowledge, as well as classroom physics.

If you want to continue to pursue electric fans as a solution to overheating at low sped or idling in traffic, by all means prove all the others wrong that have been down the road.

[RocktimusPryme]

You are taking that a heck of a lot more as a personal attack than I intended for it to be. We have conversed multiple times in cooling threads and never gotten heated (Hah!), so I don't know why you think I would be calling your credentials into question.

You are right, I didn't watch the video. All I implied was, if that dude was having to stop to cool his vehicle down as you stated, that is not the problem most of us have. If the video is otherwise then okay, fine.

Without getting complicated, I would say appropriately sized electric fans have two basic advantages over mechanical fans.

A. Less Parasitic Loss
B. Air Movement at low engine RPM.

If you have a fixed fan over a clutch fan maybe you can makeup some of the idle airflow gap, but then parasitic loss is an even bigger issue. So if your problem is at idle, its not a giant leap to try the thing that has an advantage in that area.

Conversely their biggest weakness is probably that they block a large amount of surface area so now all of the sudden when you are at highway speed you might be blocking flow through the radiator and may find out that you didn't solve you problem, only changed it.

I have no idea if this dude is right and there has never been a JK out there with a working electric fan setup, but there are plenty of people out there with 1st gen f-bodies that have functional electric fans. Not to mention pretty much every vehicle made in the last 30 years. Finding a camaro with a well-sorted electric fan setup wouldn't exactly be like discovering cold fusion.

Im also in agreement that many electric conversions are underwhelming, people always blame fan selection and that is part of it, but I think the flat cookie sheet shrouds everyone starts with don't help. When you look at a lot of OWM setups the shroud itself will have some sort of subtle convex shape leading to the fan that allows some venturi effect. WHen I was at PRI last year I was talking to both Derale and SPAL and they were talking about the shrouds more than the fans.

[70GS455]

Originally Posted by RocktimusPryme

I think this guy is having the opposite problem that nearly all of us have with the under-radiated 60s cars. Unless I am reading it wrong its not really an apt comparison.

I also never have to stop to cool down....I have to start moving to cool down. Its the stopping that's the problem. And that's where an electric fan would benefit me. I don't think anyone would make the argument that a big mechanical fan wont move more air under RPM, including racing like you said. The problem is getting stuck in traffic, or a drive-through etc. I need more air at idle.

My car is pretty well sorted out, Cold Case, big 19" clutch fan with a modded clutch to engage faster (I could probably bend it a little more even). And its fine, but it creeps enough at idle that the thought of getting stuck in a bad traffic jam scares me. And its hard to keep temp down in the staging lanes unless.

Plus I have the Terminator installed and Im not making use of its fan controls, which activates my personal flavor of autism and annoys me. Ive just always had something more important to spend money and time on than moving this one to electric.

Sounds like you could benefit from adding a slim helper puller electric fan inside the mechanical fan shroud ( if there's enough depth)

[Squidward]

Originally Posted by grivera

Since the first gen birds come with 4” (short) water pumps, would the OEM set up allow clearance for the fan?

I used to run the short nose until the impeller started slipping and the seals went out. This was at the dragstrip. Racing was over, and a buddy drove me to Autozone for a replacement, which I was surprised they had. After that I went to a long nose (3/4" difference) and a deeper pulley to realign with crank/PS.

I considered a short nose pump, but as I tried test fitting everything, I would have to go short nose AND trim the shroud drastically, and/or mod the radiator mounting brackets. The Dorman version of the mk8 is just TOO thick.

Years ago, I had a Taurus fan on the bird. Interestingly enough, I had the OPPOSITE situation: When the fan was running at idle, it seemed to do better, but then I had creep at cruise and highway drives. I attributed this problem to the fan thinking it was blocking air at cruise. But I think now that it was more a result of running a poorly flowing thermostat that couldn't flow enough coolant when wide open. So I went SIMPLE: clutch fan and shroud, and I run the smallest wp pulley to maximize coolant flow AND fan speed. I enjoy playing with gizmos and gadgets, but I really do appreciate simple and reliable as best I can.

So here is why I am playing with an efan: Tired of getting a 34 lb rectal pucker every time I get stuck in traffic. Drive thru's are part of why we have these cool old cars, so I don't want to forego those. And I spent the money to put AC in this car, and I want to use it.

Data point: My 04 GMC 5.3 had a standard 28" radiator and clutch fan. With AC on and idling in a drive thru, it would creep to 220-ish or more. Putting it in neutral and giving it a rev to 2-3k for 5-10 seconds would bring it right back to 195 due to the increase in airflow and coolant flow. Interesting case in point: Heavy duty cooling option got you a 34" wide core. So I upgraded to a 34" radiator, even still using the shroud for the 28" core (I know, I know... it's on my list). It does better, but will still start to cook a little bit when it's 115+ out here. Never a problem at speed, tho.

Another interesting data point: In 2005 GM went to dual electric fans on their Sierra's and Silverados, and never looked back. A factory dual efan setup is a project on the horizon for my truck, unless I get a 2nd gen as a daily driver...

If I lived back in Michigan, I would likely think differently. I wouldn't care about AC so much, and cooling wouldn't be as much of a challenge. Just keep the windows down, and try not to swallow too many bugs.

[dataway]

In general I'm not a fan of electric fans on our old cars since the OEM system works great if properly installed and maintained ( stock engines )

However, whatever GM did on my Sierra cooling system is outstanding. It's got the two fan setup, HD cooling package, tow package etc.

I have never seen it get above the T-stat rating in it's entire life, not on the hottest day, towing 6,000 lbs up the steepest mountain, with AC full blast. Sometimes I think they nuked the gauge in some fashion so it never goes above 220.

I have seen the Trans temp go up some in the above scenario.