FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: cjshaker on May 03, 2017, 07:35:39 AM
-
I know this is pretty common knowledge, and that many of you watch Motor Trends' Engine Master videos and have probably already seen the latest one about cooling fans, but just thought I'd throw this out there for those that don't.
It really kind of drove it home just HOW much power you're giving up by using a standard cooling fan. Even the best type, the clutch fan, which I had considered going to, gave up over 20 HP. The "high performance" fans were even worse, robbing as much as 31 HP. It's hard to ignore this fact and I'm now considering switching over to electric. Can't say I'm a 'fan' (pun intended ;D) of adding more weight and more complex wiring, not to mention having to switch over to the 3G alternator, but to ignore the HP gains seems stupid. Who wouldn't want an extra 30 HP without even having to touch your engine?
I like simple mechanical designs. Very little to go wrong and much easier to work on, but I think I'll take a little stroll on the Dark Side...
Has anyone had a direct comparison to ET gained from switching from mechanical to electric?
The link to the Engine Masters video for anyone wanting to watch it...
https://youtu.be/ZXdLgaFXZzs
-
Car Craft did the same type test a LONG time ago, and came up with similar results. I'm usually a "simpler is better" guy as well, but hard to pass up the benefits, plus no fan to worry about cutting off a thumb while you're working on a running engine. I run a simple 1 wire 100amp alternator and it runs my fan OK.
-
I respectfully disagree. Below is the old CC fan test and it clearly shows only a 7.7 hp non-thermal STD clutch fan loss to an electric fan.
http://www.network54.com/Forum/215655/message/1066184641/Car+Craft+Cooling+Fan+Dyno+Test
My '70 Mach 1 (490 hp worked 358 CID Windsor) has the same set-up, reliable as all get out. I can live with the reliability for only a small hp loss.
I know this is pretty common knowledge, and that many of you watch Motor Trends' Engine Master videos and have probably already seen the latest one about cooling fans, but just thought I'd throw this out there for those that don't.
It really kind of drove it home just HOW much power you're giving up by using a standard cooling fan. Even the best type, the clutch fan, which I had considered going to, gave up over 20 HP. The "high performance" fans were even worse, robbing as much as 31 HP. It's hard to ignore this fact and I'm now considering switching over to electric. Can't say I'm a 'fan' (pun intended ;D) of adding more weight and more complex wiring, not to mention having to switch over to the 3G alternator, but to ignore the HP gains seems stupid. Who wouldn't want an extra 30 HP without even having to touch your engine?
I like simple mechanical designs. Very little to go wrong and much easier to work on, but I think I'll take a little stroll on the Dark Side...
Has anyone had a direct comparison to ET gained from switching from mechanical to electric?
The link to the Engine Masters video for anyone wanting to watch it...
https://youtu.be/ZXdLgaFXZzs
I know this is pretty common knowledge, and that many of you watch Motor Trends' Engine Master videos and have probably already seen the latest one about cooling fans, but just thought I'd throw this out there for those that don't.
It really kind of drove it home just HOW much power you're giving up by using a standard cooling fan. Even the best type, the clutch fan, which I had considered going to, gave up over 20 HP. The "high performance" fans were even worse, robbing as much as 31 HP. It's hard to ignore this fact and I'm now considering switching over to electric. Can't say I'm a 'fan' (pun intended ;D) of adding more weight and more complex wiring, not to mention having to switch over to the 3G alternator, but to ignore the HP gains seems stupid. Who wouldn't want an extra 30 HP without even having to touch your engine?
I like simple mechanical designs. Very little to go wrong and much easier to work on, but I think I'll take a little stroll on the Dark Side...
Has anyone had a direct comparison to ET gained from switching from mechanical to electric?
The link to the Engine Masters video for anyone wanting to watch it...
https://youtu.be/ZXdLgaFXZzs
-
Thats assuming the Car Craft test is the accurate one....
Either way, 10-20hp through a wide RPM range, with something as simple as reducing parasitic drag seems like a good update.
All depends on priorities of course, if a guy isn't trying to optimize his combo it's not a big deal. Any vehicle built in the last 10-15yrs has an electric fan so not sure what the issue is with reliability.
-
I use electric fans on everything - got tired of dodging the 16"~18" salad shooter engine driven stainless blades. A also engineer the radiator/fan setup as a unit. In most cases, a couple of bolts and disconnecting a plug allows the entire assembly to lift out of the car for front motor work. Combined with a quality electric water pump it frees up space and reduces power loss. Add in my preference for electric fuel pumps too. You get to where the whole motor including alternator is assembled on the stand, then drop in, connect a couple of harness plugs and a few wires, connect fuel line, bolt on headers, drop in radiator assembly and done under the hood.
-
Im that kind of guy to why put on more electric stuf ?
But 30 hp, even if you dont are after those last extra
horses,they burns a lot of gas those 30 horses
-
As for modern car fan donors I personaly have not seen many problems with the Ford Taurus compared to Jeep being the most problematic. If you drive your vehicle more than 3000 miles a year you may come out ahead buying a new fan and switch from Ford, if you can still get them.
-
I run two Spal electric fans, one 11" and one 12 " on my 67.
They are pusher fans which I know is not as good as puller but they cool fine in AZ summer heat.
It sure is nice to work on with all that room.
It's been around 10 years and they've been reliable but I can't say I drive a lot of miles.
Now for the electric fan hp loss I ran back to back 1/4 mile passes with and without the fans turned on and
found no discernable difference in the ET's. The car was very consistent ET wise so I believe the results.
-
Usually an engine driven fan is bolted to a mechanical water pump, so you need to consider both. I always figured a water pump with a closed thermostat used more power than a fan.
Nick
-
Yes, the really hot set-up would be an electric water pump and electric fans. But I've not seen a current back-to-back test of same. Anyone here have any test article to post up?
-
I respectfully disagree. Below is the old CC fan test and it clearly shows only a 7.7 hp non-thermal STD clutch fan loss to an electric fan.
Bob, I would think that Steve Brule has some of the best equipment available for testing. I would guess that their dynos are modern and pretty darned accurate, so I'd be inclined to believe their testing, but admittedly they didn't test a non-thermal fan either. I really do prefer simple and reliable, but because I'll be switching to an electric pump, I'll basically have no choice. But I'll admit that not having to fear for my hands and fingers is pretty appealing also. :)
Combined with a quality electric water pump it frees up space and reduces power loss. Add in my preference for electric fuel pumps too.
Chris, that's the thing. I bought a set of Jays' water pump adapters and am planning on switching to a CVR water pump, which would necessitate an electric fan. For the money, I think it's about the cheapest horsepower upgrade one could do. With the O-ring seals on Jays' adapters, it's also appealing for the easy access to the front of the engine without having to deal with gaskets every time.
-
My dyno test, with a fixed blade aluminum fan and an Edelbrock pump vs. an electric fan and the CVR pump showed a difference of about 20 HP at 5500 RPM. Almost no HP change up to 3500 RPM, but then it starts and grows with RPM. I could easily see a 30 HP improvement if you were spinning the engine to 6500+. Another point of reference might be what I read somewhere a long time ago, about the mechanical water pump on the SOHC. It was said that cooling systems pressures of up to 90 psi were recorded at 7500 RPM at some point in the cooling system for those engines. For the pump to develop that much pressure in a recirculating system, you know it was taking some power...
-
Thanks Jay as we now have a good point of reference. I do wonder though what the net would have been with a non-thermal OEM type clutch fan and the electric pump. Maybe someday.....................
-
Just to back up Jay's testing with the "Fan laws" as stated volume increases directly with rpm. Double the rpm = double the flow. Static pressure goes up by the square. The hp required goes up by the cube. So if the fan was consuming 3 hp at 3500 rpm then at 7000 rpm that should be 27 hp. Of course this assumes the fan is not in stall. The "laws" work for centrigual pumps as well. So if the pump is generating 10 psi in the system at 3500 rpm then at 7000 rpm it would generate 100 psi.
-
I suppose that that info was in your book, but there's so much info in there that it tends to get lost in my memory ::)
I recall Blair talking about water pressures with standard pumps on high RPM engines and that had crossed my mind also.
-
If a person wanted or had to use a stock belt driven water pump the same concept as a clutch fan could be used in the waterpump housing. The impeller could back away from the cover to regulate psi and be over ridden by temperature. Seems it would be a fairly easy power saver. Easier than hiding nitros in a pillar or welding a C6 bell housing to a C4.
-
No electric fan will ever flow the cfm of a real fan.
-
How much of a Hp power draw does the 3G take compared to a standard unit? Are you moving the HP draw from one device to another?
Joe
-
No electric fan will ever flow the cfm of a real fan.
Who told you that?? My Spal fans pull more air than I've ever seen a mechanical fan pull.
-
How much of a Hp power draw does the 3G take compared to a standard unit? Are you moving the HP draw from one device to another?
Joe
Its pretty minimal. You can calculate it by knowing that 1 HP = 750 Watts. So for example, let's say that you are changing from a 60 amp alternator to a 200 amp alternator. That is a difference of 140 amps. Let's also assume your charging system is putting out 14 volts. Power in watts is equal to current (amps) multiplied by voltage. So, 140 amps X 14V = 1960 watts. 1960 divided by 750 is 2.61 HP. If your alternator is only 50% efficient, that's about a 5 HP difference. And the alternator is probably a lot more efficient than 50%. Plus, your 200 amp alternator is not putting out 200 amps all the time, it is only delivering that amperage when it is required.
Now let's look at an electric fan, that draws 15 amps continuous at 14V. That is 210 watts, and again assuming a 50% efficiency in the alternator, the alternator is requiring 0.56 HP to generate the power for the fan. On the other hand, per the previous posts you can expect to lose at least 10 HP running a mechanical fan. Is it any wonder all the new cars have electric fans?
-
I sure wish they had tested a non-thermal clutch fan. It would seem that type of fan would disengage more as rpms and drag increased. A thermal clutch fan might not.
JMO,
paulie
-
I sure wish they had tested a non-thermal clutch fan. It would seem that type of fan would disengage more as rpms and drag increased. A thermal clutch fan might not.
JMO,
Paulie
Simulate driving conditions with a 70 mph fan blowing on the front of the engine. The engine fan drag won't use as much hp on the road as compared to a stationery dyno. I think if someone was dedicated enough they could modify the water pump like I mentioned. If a turbo can be produced with variable pitch the same could be done on most pumps. Less of any engine drag means better economy for any vehicle.
-
I found out when i lost a fanbelt if i drove over 70 mph
the fan rotated the waterpump enough to not overheat
So some of the powerloss must help to pull the car forward.....
How do we test that? :o ;) :D
-
I know lotsa drag racers with electric water pumps and fans.
I don't know many that run them while doing a run.
On the street I don't see how it matters.
I run electric fans simply for packaging reasons.
-
I know lotsa drag racers with electric water pumps and fans.
I don't know many that run them while doing a run.
On the street I don't see how it matters.
I run electric fans simply for packaging reasons.
I bet under a certian speed it matters a lot. I had a 19 1/2" cluth fan lock up on my truck once. After 4000 rpm it could be heard very well over the glass packs. A man I knew with a 99 Powerstroke put a kit on his cooling fan that assisted engine braking. I can't tell you anything about them or how well they worked though.
-
Yeah, I had an 89 F250 like that. Sounded like a B17 and was obvious even over the diesel engine.
I love fan clutches. Sadly I have no room in my vehicles for them.
-
I had a big 8 blade fan with stainless blades
Oem FoMoCo from what i dont know
That was the first thing you heard of my
Fairlane. It sounded like a Hoovercraft
before you could hear the engine
-
Yeah, I had an 89 F250 like that. Sounded like a B17....
Hmm, now if it sounded more like a Corsair, I'd seriously consider switching over ;D
-
Summer is coming and i want to reduce the thermostat in by 428 down to a 160 (195 in it now) and consider an electric fan now that i have a 3G alternator. Wondered what you used in your SOHC galaxie?
Thanks
-
I don't recall the thermostat temp that Jay uses, but I know he uses Spal fans, and I agree that they're the best.
-
Yes, both in the Galaxie and in my Shelby clone I use 160 degree thermostats and two electric Spal fans. The radiator in both cars is also large, 31" X 19", aluminum with two 1" cores.
-
No electric fan will ever flow the cfm of a real fan.
Yea, they do. OEM quality too. Cheap in the yards, motors available at any parts store.
(http://raceabilene.com/misc/LT1fanB.jpg)
-
I was referring to a mechanical fan, not electric. Sorry for the confusion. Spal actually makes a lot of the OEM electric fans...
-
LOL. I don't know who the OEM is on those but they came off an LT1 Camaro. They work like gangbusters. I can make a pass, come back at 200F or better, run the fans and electric water pump for 60 seconds and be below 180F.
-
I know lotsa drag racers with electric water pumps and fans.
I don't know many that run them while doing a run.
I always run the water pump while making a pass. Need to get the heat out of the chamber.
-
Sorry Barry, I was unclear. I meant running the fans.
-
In the Falcon with the big fans, I run only the water pump during a run. With a 31x19 radiator, don't really need them on a pass. Same with the 300 HP 302 and the old 500 HP 351C. The Mustang has a smaller radiator and small 10" fans, so it runs the fans as needed to control heat. Driver preference (wife) on that one. She just has one override switch to cool the car in the pit. In the dragster, with the radiator behind the deflector plate, fan and pump run starting when I leave the Ready Line heading to the burnout box. The water pump ALWAYS runs - the control switch panel in the dragster has two positions: pump, pump+fan. In the door cars, ignition on = pump running.