People in the auto news forum are just ahead of the curve.

 

I think this thread by far is the most intresting (and refreshingly expertly) discussion I've seen on any thread on any site in a very long time.

Although we've gone seriously off subject, this is one of those threads you just sit back and read.

 

Sorry to dissapoint, but it's not a gasser, it's a diesel.
Did the 460/C6/4.10 thing in a '75 F-150 Trailer Special.
Pulled like a dozer, and had similar mileage too. 7-8mpg full or empty,

Now running a 7.3 PowerStroke... Stock with "a little help".
20-21mpg empty, never worse than 17mpg loaded to the gills.
3.55:1 rear, 4x4 Off-Road package, towing pkg, extra cooling, etc
Power captains chairs, cloth, CD, power everything.


To the theme of this thread, I bought my truck to WORK. I pull horses, cars, boats, tractors, hay, and anything else I need to to run a farm and enjoy my hobbys. I frequently have 1000-2000lbs in the bed of the truck, and the only difference you notice is that the ride is smoother with weight in the bed - otherwise the diesel never knows you have anything in there.
I have to put 5000lbs behind it to really start noticing there's a load via the accelerator.
In the image above, I bought a King Cobra and met a guy in Delaware to pick it up. With the KC on the trailer, and a spare engine and transmission in the bed of the truck, I was able to come down US-81 through Virginia towards NC running 75-80mph in overdrive (which is really a no-no) with cruise-control on, and the truck never shifted out of O.D. - it was incredible. I have hundreds of stories like this now, and all it has done is made a believer out of me - diesels are the sh1+ when it comes to work trucks... period.

This is why I am so "uninterested" in these new gas engines with "381hp" in a 1/2-ton. I think marketing is pushing these truck designers and engineers into a bad situation - basically they are going the wrong way IMO. If they want high-hp speed trucks - then fine, go the way of the Lightning and SRT Ram. But don't dope-up the regular work truck and try to make it something it should not be.

 

Another thought on the Hp v. Tq discussion...

Do you guys understand that you can gear a car (or truck) to make MORE Tq at the wheel, but not more Hp?
I guess a better way to say this is that for any given engine, you can alter the gearing - via transmission ratios, rear axle ratios, and even wheel/tire diameter - and actually multiply or reduce the torque value acting between the tire and the asphalt.
But the actual horsepower value will not change via gearing or ratios.

What this means for the average driver is that you can gear your car in a way such that you can overcome a Hp deficit for a short period of time. Any 5.0 driver realizes the benefit of dropping in a set of 3.73s to replace the 2.73s most cars came with. It made the 5.0 with 225hp competitive on the street with cars having 285 or even 320 hp. It was the first mod most 5.0 owners did to get "serious" about launching, and it made the 5.0 a wicked player for stoplight jumps and 1/8th tracks.
Of course the down-side to this was that you run out of wind on the top-end, and the cars able to make the Hp and run lower gears to boot simply drive away. Also a fact many 5.0 owners are aware of.

It goes back to the point I made about torque being independent of time (completely) whereas power is time-dependent.

And to contradict what has been said earlier - you CAN have Torque without Power.

Suppose you have a bolt that is welded to the plate it was screwed into (go with me on this).
You put a wrench on the bolt and apply 100 ft-lbs of torque to the bolt, but it doesn't move because it's welded.
You ARE putting 100 ft-lbs of torque on that bolt - no doubt!
The torque wrench tells no lies.
You can apply that force (torque) for minutes, hours, days... but it won't move.
Until it moves, you have not completed any WORK (force through distance), or used any POWER (work per unit time).
So you can have torque without power, but you can not have power without torque.
Which of the two "sounds" more important to have?

Things that make you go "Hmmmmm".

 

That is incorrect

Torque can be measured at the engine, and it can be measured at the wheels. Similarly with horsepower.

HP = (TQ x RPM) / 5252

That's the formula. If you alter TQ, you alter HP. When you alter gearing, you modify TQ at the wheels, but not at the engine. And your wheel HP will be modifed as well, not engine HP.

What you're talking about is the total work done by the engine may not change. This is difficult to achieve/measure, as that depends on the total area under the graph (you need to use integration).

Incorrect as well . You are applying 100 lbs of force, but you do not have torque. Torque is the force that produces rotation. It causes an object to rotate. Without rotation, you got no torque.

Physics, engineering and all that jazz gets funny when you get into details and work with actual definitions of words.

 

Back on the Ford Trucks... My friends who lives and breathes Ford belive that they are going to go back to a push-rod style motor starting in the trucks around 09-2010.

 

Boss isn't a pushrod... it's a SOHC 2v
So that would be a negative.

 

I'll debate with you til pigs fly on this one friend.
Suppose you have 100ft-lbs of Tq at 100rpm from the engine.
In case #1, we have a 1:1 drivetrain with no efficiency losses, so 100ft-lbs make it to the pavement at 100rpm tire speed.
If you change the rear gear to 2:1 and run the engine at the same speed (100rpm), you will get 200 ft-lb of torque, but you will only have 50 rpms at the tire.
According to your own equation... at the wheel...
Hp1 = (100*100)/5252 = 1.904hp
Hp2 = (200*50)/5252 = 1.904hp
Hence, DOUBLE the torque, but SAME horsepower.
Just like I said.

The engine can NOT make any more power - regardless of how you gear it.
But you can change gearing around all you want and play games with the Tq.
You err in what I highlighted in red.
NO gearing change can affect total power in a common driveline.
Law of Conservation of Energy ---> Power in = (Power out - losses of efficiency)


NO, without rotation you got no WORK.
Work = Forcee through distance and/or torque through rotation.

I'll contest you til pigs fly on this one too.
Torque is a force applied at a distance from a center of rotation.
That applied force (or torque) does NOT have to result in movement to exist, the unique thing is that it is being cancelled by another (reaction) force... but it DOES exist.
What is still at a value of zero is the WORK done, because work is dependent on movement or displacement. No move, no work.
Since power is work per unit time, no work, no power.

You see, in the totality of my simple example, we neglected to account for things that are "given". If we do a summation of forces about the center of rotation, we simply find that the applied force (that we are putting on the torque wrench) is being countered in the opposite direction by the bonding forces of the weld at an atomic level. In other words, there is a "reactive" force that is countering the one I am applying. Sum of forces = 0, so no acceleration, no move, no work, no power, but the applied force (Fa) is VERY real.

Now if you really want to get into micro-statics, we have technically deflected the bolt at a microscopic level, and it has in fact rotated a miniscule amount, but not so much that it has overcome the Van der Walls forces and resulted in permanent deformation of the steel. It will in fact flex back to it's original position when the pressure is released, so what we have really done is stored some potential energy in the system while it was deflected, and released that energy when we removed the applied force, still resulting in a net work of 0, and net power of 0.

 

I'll be surprised.

One thing all the complexity of OHV engines does allow is varied valve timing and combustion adjustments. As fuel regulations change and emissions get ever harder to comply with, I suspect that alterior benefits will become more profound in OHV engines in the future.

I further suspect that combustion engines will basically evolve through OHV configurations until they are replaced by hybrid and eventually electric motors.

I see the future of pushrod engines as dim. Not snubbed out, but dim.
The LSx series from GM flies in the face of conventional pushrod theory, but even those magnificent engines have design limitations.

 

Thats true but they just can't keep up with the power without adding a blower. I'll call my friend i got this from a little later and see if i can get more info.

 

But what happens when the guy that has 320 HP...say...a 99 Cobra....goes from 3.27s to 4.56s?

We gotta hook up sometime at a show, meet, or race....you're only about 4 hours SE of Va Beach.

Bob

PS....I'm selling my Hog, and will likely bring an old friend back into the garage.

 

You use gearing to make up for torque deficits, not HP deficits. That is why you can have a Formula 1 car that makes only a couple hundred ftlbs of torque at the motor have very high instant acceleration values. Although they are only displacing 2.4L, they rev to 19,000 RPM, and could tow any size trailer of hay bails if you geared it right and had the right clutch (or an auto).

(Of course F1 cars weigh nothing, but that isn't the whole story).

 

I stand corrected on both counts. First, my definition of torque was not correct, I thought motion was required.

Second - i didn't take into account varying RPM (duh - it's in the formula), but that's because i was thinking more of cars, gearing and dyno.

I remember my grade 12 physics teacher telling the class to lift up our chair. He said while we're lifting, we're doing work. He would pay us for working. Once we lifted it, he said to keep the chair lifted. We were not doing any work and he would not pay us for holding the chair. That was a funny way to illustrate definition of work in physics.

 

I can't go along with that.

GM's 4.8 runs 295 horsepower and 305 torque. The current 4.6 in the Mustang runs 300 horsepower and 315 lbs/ft of torque.

Move to the GM 5.3 and you're talking 320 horses and 340 torque in top tune. Meanwhile, the latest Ford 5.4 Triton makes about 300 horses, yet belts out 365 lbs/ft of torque.

In both instances Ford not only keeps up in power, they arguably set the bar and set the pace in power at displacement.


You make the mistake that's often made when comparing GM's pushrod and Ford's cammer engines. People tend to throw everything Ford makes against GM's larger 5.7, 6.0, and 6.2 engines, despite them being smaller in displacement. Ford substitutes larger displacement with more cams and/or a supercharger and has arguably done a splendid job at it when you pit the blown 4.6 against a GM 6.0 or 6.2 engine (remember, the blown Cobras were underrated by at least 20 horses). The blown 5.4 (an engine barely any larger in displacement than the small V8 in the Impala SS) puts out as much horsepower as the Chrysler SRT V10, and is structurally capable of putting out significantly more.

Give credit where credit's due.

GM is great at getting high fuel economy and amazing life out of large V8 pushrod engines. But Ford's OHC V8s are by no means behind the curve.

Though the Ford V8s do have drawbacks (mainly cost to manufacture and physical size due to the massive heads on them) saying they can't make the power without a blower is false. Displacement to displacement, and the fact that Ford spends the extra money on forged internals, their engines put out the power.... and are friendly to blowers to boot.

 

Another factor is the use of the power curve. Using 4.56s instead of 3.27s allows the car to stay near the power peak for a longer period of time.