[Kirk's67SS]

Well put Tony and is exactly what I was indicating
only you detailed it out beautifully

That is what "hydro462" and "Gtogeoff" do not seem to understand when they make a Blank Statement of
" Use the stock clutch fan and forget the toy plastic junk that blocks air movement through the radiator while the car is moving..
There is NO way the electric will even come close to a clutch fan in air movement and efficiency..... "

Shows me they do not seem to understand all of the facts/factors involved . IMHO

 

[SSJohn]

I did the efan thing for a while. Didn’t work out. Now running stock shroud and 1318 fan. Running cool in all situations.
Back in the day, the engineers at gm knew what they were doing.
As far as today’s cars, hard to put mechanical fans on transverse mounted engines.
For all the rest that aren’t, it’s a matter of cheap as possible. Corporate profits rule manufacturing these days, not engineering. Progress is not always a good thing.

 

[69SS454]

This must be like a Ford Chevy argument. Both can be made to work. There are more factory electric fan cooled V8's being made now than mechanical clutch fans.

 

[Buzzbomb]

I took the recommendation of the Derale Heavy Duty fan from this site many years ago. No complaints here...It's well built, and I'm not sure if one extra blade is worth $20 more. This fan blows a TON of air.

http://derale.com/products/belt-dri...-driven-fans/heavy-duty-flex-fans/standard-rotation2013-10-28-09-53-27333213833

 

[1966_L78]

This must be like a Ford Chevy argument. Both can be made to work. There are more factory electric fan cooled V8's being made now than mechanical clutch fans.

True... Many people will adapt some junkyard parts (remember when "Windstar" fans were so popular?)... Others will but the cheapest electric setup they can find, and still others will still buy the cheapest flex fan they can... Or buy some off-brand at a swap meet, etc...

Yes, GM engineering made sure these stock cooling setups were sufficient, of course that was with maybe 450 HP of the LS6 (what was the net HP?). More power equals more heat, so a stock setup may be fine for a mild build or a stock resto, but even back in the '60s, the bean counters were still predominantly in charge, so the cooling systems were adequate for their intended design...

Of course, IF the stock setups were really so great, then companies like Be-Cool, DeWitts, Griffin, Hayden, Derale, etc, etc, etc wouldn't have much if any aftermarket business...


Of course, it just goes to show the complexity of automobiles in general... Too many factors: timing, mixture, engine size, cylinder wall thickness, water pump, pulley ratios, radiator cores, fan design (4-blade, 5-blade, 6-blade flex, 7 blade, clutch/no-clutch), shroud, crossflow/downflow... Nearly impossible to get an apples to apples comparison...


On my latest project ('66 SS) I am planning a "stock" mechanical fan setup with a stock shroud and a 4-row radiator, but using a "1970" 7 blade fan and the HD Hayden clutch because I feel that's better than a stock 1966 5-blade setup (the 5-blade uses a different mounting pattern, and Hayden does NOT make a HD clutch for that model). But I am still considering adding some supplemental electric fans to help with low-speed cooling...

 

[v8440]

I have had electric fan setups and mechanical fan setups that work in the AL summer heat. My preference is generally electric fans, as they continue to do their max at idle when the car is not moving. Yes, mechanical fans can move 6 billion cfm...when the engine is well above idle. This usually means the car is moving, often not slowly. In other words, when you don't need it most. You can't have BS wiring for a powerful electric fan, nor can you have an alternator that's weak in low rpm charging. There's no free lunch here, an electric fan is not a magic bullet and it does impose some electrical requirements that older cars generally don't meet with stock charging systems.

However, if you're willing to do the work to install a truly strong electric fan setup, you can free up some horsepower and save some gas as well. It's really personal preference, both will certainly get the job done.

 

[70GS455]

I have both....slimline electric helper fan inside the shroud along with mechanical clutch fan.

Sent from my SM-T817V using Tapatalk

 

[v8440]

I've often wondered about setups like that, and setups with both puller and pusher fans. Do the "extra" fans hurt airflow through the radiator beyond a certain speed? It may be that they do, but perhaps by that point there's still enough airflow to keep things cool. It would be neat to do some experimentation along those lines.

 

[70GS455]

I've often wondered about setups like that, and setups with both puller and pusher fans. Do the "extra" fans hurt airflow through the radiator beyond a certain speed? It may be that they do, but perhaps by that point there's still enough airflow to keep things cool. It would be neat to do some experimentation along those lines.

Look under the hood of a late model Dodge truck. They use that setup. Now granted they are not cooling a 500 hp engine, but they don't overheat (at least mine didn't).

I'm sure when the fan is off, it presents some amount of reduced flow. But how much...idk

Sent from my SM-T817V using Tapatalk

 

[Malibu ss 64]

I've often wondered about setups like that, and setups with both puller and pusher fans. Do the "extra" fans hurt airflow through the radiator beyond a certain speed? It may be that they do, but perhaps by that point there's still enough airflow to keep things cool. It would be neat to do some experimentation along those lines.

Several older cars late 80´s early 90´s with mech fan and ac has an extra electric pusher fan that goes on when you run the ac.

 

[Gtogeoff]

Kirk's 67 SS.

If you are going to quote me in inverted commas, at least get the quote correct. You didn't.

I tried dual 14" Ford V8 Efans on my car, both fans at full speed, with an integral shroud that was a near perfect fit over the radiator, & the engine ran noticeably hotter compared to my trusty 19" clutch fan. The Efans came off the same day....gather dust on the rafters.

You don't seem to understand how clutch fans work....They do not run at fan belt speed, the clutch slips internally so that the fan speed is lower than the belt/pulley speed. At a certain higher built in speed, the clutch overruns & the fan does NOT speed up with the engine. For obvious reasons. The clutch needs to be matched to the fan. That is why clutches come in different ratings such as std, heavy duty, severe. Using a large 19" fan with blades with steep pitch with a std clutch will cause the clutch to slip more & cool poorly. Guess what gets blamed for the poor cooling...

 

[Malibu ss 64]

Kirk's 67 SS.

If you are going to quote me in inverted commas, at least get the quote correct. You didn't.

I tried dual 14" Ford V8 Efans on my car, both fans at full speed, with an integral shroud that was a near perfect fit over the radiator, & the engine ran noticeably hotter compared to my trusty 19" clutch fan. The Efans came off the same day....gather dust on the rafters.

You don't seem to understand how clutch fans work....They do not run at fan belt speed, the clutch slips internally so that the fan speed is lower than the belt/pulley speed. At a certain higher built in speed, the clutch overruns & the fan does NOT speed up with the engine. For obvious reasons. The clutch needs to be matched to the fan. That is why clutches come in different ratings such as std, heavy duty, severe. Using a large 19" fan with blades with steep pitch with a std clutch will cause the clutch to slip more & cool poorly. Guess what gets blamed for the poor cooling...

How did you wire the fans and what alternator did you use?

 

[StevenS]

I read so many times never to put a pusher fan on the front of radiator. My pickup which has a 468 chevy has just that. Has the stock radiator with a flex fan. Runs 180 all day. But if you get stuck in traffic for a long time I have seen it go to 200. Which still is ok IMO. But the truck came with the fan in front of the radiator. I flip the switch and the truck runs 180 at idle and switch it off and it still runs at 180 cruising. So do what works.

 

[v8440]

I read so many times never to put a pusher fan on the front of radiator. My pickup which has a 468 chevy has just that. Has the stock radiator with a flex fan. Runs 180 all day. But if you get stuck in traffic for a long time I have seen it go to 200. Which still is ok IMO. But the truck came with the fan in front of the radiator. I flip the switch and the truck runs 180 at idle and switch it off and it still runs at 180 cruising. So do what works.

It's not that folks are ignorant; it's just that a lot of what they know ain't so. Sort of falls into the "never say never" category.

 

[Skier_Bob]

Update - rewired electric flex a lite fan to sensor in manifold; 185 thermostat - ran consistent 180-185. highway trip for 40 min with occasional slow downs but not bad traffic. not sure it's the result I was hoping for but better than 200+.

Will run this set up for a bit then switch to 160 thermostat as next step towards clutch fan. or flexalite fan..... we are about to move from oppressive heat to Louisiana fall, so temps won't be as bad..

Why is it that I don't worry that my 2014 Silverado V8 runs a 210 all the time????

 

[SSJohn]

Why is it that I don't worry that my 2014 Silverado V8 runs a 210 all the time????

That’s because all modern engines are designed to run that hot for emissions reasons. My 2007 jeep runs at 210.

 

[70GS455]

That’s because all modern engines are designed to run that hot for emissions reasons. My 2007 jeep runs at 210.

Yes. They have a 210 thermostat from the factory

Sent from my SM-T817V using Tapatalk

 

[Dbull]

I don’t know how many folks this will help,but my 71 350 with R134 conversion would stop cooling and the temperature gauge would slowly creep up while sitting at red lights.I was using a seven blade fan and clutch assembly,which I thought was as good as it got.While at the local pick&pull I noticed a mid seventies Cadillac with a factory flex-fan using only a spacer.I deduced that if it keep that big cube Caddy cool it would be worth a shot on my stock 350 and after all it was only $7 for the fan,spacer and bolts,not to mention the reduction in rotational mass.I bolted it on and,low and behold,it lined up perfectly with half of the fan in and half out of the shroud.The amount of air being pulled through the radiator and condenser at idle was noticeably increased.The temp gauge stabilized and my cold ac at idle returned.Keep in mind that this is a stock 270hp/350 with a 2:73 gear,so high rpm’s are not a problem.For $7 this might be worth a shot for a lot of budget minded owners.

 

[v8440]

That's interesting, I had no idea cadillac (or anyone else for that matter) used non clutch fans by the 70's. I'll have to keep an eye out for one of those. My chevelle doesn't need it, but it would be a good thing to have on hand for something else some day.

 

[Super-H-Mike]

I got tired of the dual elec fans setup on mine. Too much power drain, noisy, had to keep an eagle eye on the gauge and keep turning them on and off. Tried automatic temp sensors and it never was reliable. I went with a stock repo shroud and a 17 inch clutch fan from a mid 80s Camaro 305cid. This works perfect for me. I have a big full aluminum radiator and a smallish pusher fan just in case but it never is needed. 180 is as hot as it ever gets. Every time I look at the gauge now it just makes me smile! 70 502 auto no AC.