That would be a good test.

_________________
1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

"They were not testing the cooling capacity of each fan."

I agree, maybe they should have instead tested the cooling fans for weight, or color, or db level, or MOI, etc. (that's sarcasm to be perfectly clear )

They ran a test IMO to support a conclusion they already had. A better more useful test would be one that at least used a targeted amount of air, and then varied the size of fan in each style, to meet the target temp, my assumption being a smaller fan would consume less hp and a better solution if it reached target temp. I don't think it would have been beyond the testers capability to just forget the dyno, and just use a suitable electric water heater source to measure fan cooling with a variable speed electric motor, and measure its current draw, leave the engine out of the picture. Adding the road speed fan would be additionally informative. But then GIGO still applies.

not exactly,, one factor tests are always intended to provide direction only, unless the single factor being tested can account for 100% of the variability.

It appears to me the video authors are saying 'cooling fans take power to run and some fans take more than others' and the tests ran prove that.
Would have been silly to run the dyno pulls then not provide any hard data. The HP numbers developed are probably repeatable for each fan design, but everyone would agree there are other factors that influence fan drag.

It also appears that the test process was valid: same dyno, same engine, tests ran as concurrently as possible with the same operators. What else could you ask for?

To come to a final conclusion of HP loss due to cooling fan design one would need to either gather realms of data and use regression analysis to determine what variables impact HP or identify the variables to be studies and use anova designed experiment. Either of these methods would require much more testing dyno time and a you-tube video hours in length to explain the analysis and how conclusions were confirmed. That is beyond the intended scope of the video.

I see the purpose of the video to directionally state that with other variables held constant, some cooling fan designs have more or less engine drag, and the video did that.

Chrysler's own slant six data can be used to support the video's conclusion.

The slant six was originally rated at 145 gross hp. That is hp at the flywheel with no accessories.

In 1972 it changed to 110 net hp. That is hp at the flywheel with accessories.

35 hp loss with fan and alternator would be consistent or at least close to the video's findings.

_________________
1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

No, there are wayyyyy too many guesses and assumptions stacked up in what you are calling Chrysler's "data" to support the assumption you've just made.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

What am I guessing at? 145 hp gross and 110 hp net are Chrysler's numbers.

_________________
1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

Oh, brother. If you're interested to discuss what I actually wrote, fine; we can start once you've read and understood this.

Until then: good day, sir.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

You're forgetting the exhaust system and that 145 hp was a lie to begin with. Go look at a Dodge truck data plate of the 1960s and you'll see that essentially the same 225 that was 145 hp in a passenger car was 127 hp net in a pickup. In 1972 with passenger car emissions controls and exhaust system the net rating was, as you state, 110 hp. That's a 17 hp difference between non-emissions net horsepower and 1972 emissions horsepower which is half of your claim.

Let's look at this another way. A 50 amp alternator is only capable of 725 watts output and 1 hp = 746 watts, but we generally only get 500 watts or so from 1 engine hp so the alternator probably takes 1.5 hp to drive at maximum output. Dyno testing, and the clocks at drag strips have shown that the car exhaust system costs about 7 hp. By my math that leaves, at most, 8.5-10 hp to drive the fan and water pump.

Older (ended in 1956 apparently) Dodge trucks had both gross and net horsepower listed. My 1954 C1 is that way and the horsepower is 145 gross at 4400 RPM and 123 net at 4000.

_________________
Joshua

I read your post and I understand and agree with it, There are a lot of variables at play.

If you dynoed 10 1969 engines (when they were new at the time) you would have recorded 10 different hp numbers. You could dyno 10 2017 Challengers straight off the showroom floor and get different numbers. No two engines will be exactly the same.

I used the 1972 rating because not much changed from the 1971 slant 6. There were much larger hp drops in the V8's because most lost compression for 1972.

Another variable in the eary 70's was gasoline changing from leaded to unleaded. I don't how old you are but I remember how bad the early unleaded gas was.

Bottom line is that the largest drop in hp between gross hp and net hp is the addition of accessories added to the engine. The biggest power grabber is the fixed blade fan.

_________________
1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

A reasonable reply, that I disagree with in regards to my original objection. I did get some info out of the video, but had to me, about the same merit as a test of how many gallons of gas different cars gas tanks hold, and not much more. I sure beat the crap out that horse, didn't I?

Here are more realistic numbers from a 1961 225 engine, removed from a new Dodge Lancer, put through a 50-hour break-in, meticulously checked and set to factory specs, and put through well-documented tests in March of 1961, NOT by (or on behalf of) Chrysler:

Gross output (air cleaner removed)
Maximum BHP 126.5 @ 3800 rpm
Maximum Brake Torque 210.7 lb·ft @ 1600 rpm

Maximum output (just shy of detonation)
Maximum BHP 115.9 @ 3800 rpm
Maximum Brake Torque 196.9 lb·ft @ 1400 rpm

As-Installed Output
Maximum BHP: 104.5 @ 3800 rpm
Maximum Brake Torque: 189.4 lb·ft @ 1400 rpm

These numbers are notable for a bunch of reasons: they don't conveniently end in nice, tidy, round, advertising-friendly 0s and 5s like Chrysler's 145 (hp) and 215 (torque) figures. The gross BHP figure falls well shy of the published claim. It does, however, match up very well with the "127" rating Chrysler published for the industrial 225 configured and equipped just about identically to the passenger car engine in all the ways that mattered to output. That looks a lot like it was wisely decided that the only real purpose of a horsepower number on a passenger car is to sell the car, while people specifying industrial engines have a genuine need to know what they're actually getting. Also, the as-installed figure and the gross-output figure are clustered closer than the two numbers you wanted to use.

Elsewhere in the same report is a graph of fan horsepower, considering the 4-blade solid fan as installed in a 1961 Dodge Lancer. The figure rises exponentially with engine speed and peaks at all of 4.4 whole, entire horsepower at 4400 rpm in still air. That's a speed seldom seen by a 225 in real usage; consider a car with 205/70R14 tires and a 3.23 rear axle ratio, with a non-overdrive transmission. At 60 mph, that engine is spinning about 2600 rpm. At that speed, the 4-blade solid fan was eating up one horsepower in still air. Change the axle ratio to 2.76 and we're at 2200 rpm, where the fan's hogging up six-tenths of a horsepower.
With the exception of one or two companies who offered a no-lead gasoline in certain parts of the US starting in the '60s, unleaded gasoline became generally available in mid-1974. There was nothing the matter with the early unleaded gas -- it was not "bad" -- it was just only available with regular-grade octane levels (91 RON, that is 87 AKI...same as today's regular gas at sea level). It was perceived as "bad" because it didn't run well in high-compression engines that called for higher octane fuel, nor in engines that originally ran fine on regular but had been accumulating lead sludge in their combustion chambers and so now required higher octane...and there were many of both kinds of engine on the road when unleaded came in for '74.

And none of this is relevant to the question at hand for a couple of reasons: engine performance rating tests were not done on gasoline obtained by driving down to the local gas station, they were done on fuel of standardized characteristics. And there was plenty of high-test leaded gasoline available at any/every gas station well into the 1970s.
No, the biggest drop in HP between gross and net published figures was due to the rising cost of auto insurance and the increasing traction of auto safety regulators. In the '60s, bigger numbers did a better job of selling cars. In the '70s, smaller numbers did a better job. Surely you didn't think the industry devised the new net system and switched to it out of the goodness of their pure and noble hearts, so they could sleep better at night 'cause the consumer was getting a more realistic (and equally meaningless) number!
No, sir, it is not. Bigger by a large margin is the exhaust system.

(Preemptively: Not from me, you can't. It took me most of two decades' effort to get hold of it, and the terms I got it under let me quote from it, but not republish it. It is not mine to share.)

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Wow, it's hard to imagine why all auto manufactures abandoned the fixed blade fan and have almost exclusively went to electric.

_________________
1976 Feather Duster /6 4sp
1984 W100 318 727 np241
1972 'Cuda 340 4sp
1985 D250 360 46RH

No, it isn't. Front wheel drive became the prevalent drive arrangement for a number of (not relevant here) reasons. Front wheel drive is most easily accomplished with transverse mounted engines, but transverse mounted engines (in most production vehicles) don't have the crank pulley pointing at the radiator. Ergo, manufacturers needed a new non-crank belt driven way to power a fan to draw air across the radiator with the vehicle traveling at low speeds or at rest. Easiest solution? An electric fan. Once the shift was made to electric fans, the auto makers foudn it easier to keep electric fans, even on the still rear-whell drive models.

_________________
Casually looking for a Clifford hyperpak intake for cheap.

What is their definition of:

Gross output

Maximum output

As-installed output



What is and what isn't hooked up?

_________________
Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Is it really? Sorry to hear it. While you've got your thinking cap on about that, also think about this: a 22" high-lift lawnmower blade is a lot like a solid radiator fan, with the added drag of the grass it's dragged through. Oddly enough, a 4- to 5-horsepower engine is enough to swing that blade at 3600 rpm through the air and the grass at the same time, without guzzling a whole lot of gasoline in the process. Don't like that because it's a 2-blade fan instead of a 4- or 6-blade fan? Okeh, how 'bout the 3.5- to 4-horse engines commonly fitted to lawn vacuums with their 3- to 6-blade fans about 20" in diameter? Or look at the giant 30"-diameter 6-blade fans in hot air balloon inflators, powered by 7- to 8-horse engines.

Donno why you're so tightly married to your pet idea about engine fans, but I hope you two are happy together. :shrug:

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.