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View Full Version : Ford Challenger 260 V-8 Torque and HP Curves


ew1usnr
10-13-2015, 06:12 PM
I could not locate a horsepower and torque curve for a Ford 260. I took what information I could find, extended it using the equation HP = (Torque*RPM)/5252, rearranged as Torque = (HP*5252)/RPM, and extrapolated what was missing to create one.

The result is probably pretty close to being correct. It clearly indicates that the 260 was designed to deliver low end torque (red line) rather than high end horsepower (blue line). The engine red lines at 5000 rpm.

5183

Notes:
The equations equation HP = (Torque*RPM)/5252, rearranged as Torque = (HP*5252)/RPM are referenced here: http://www.epi-eng.com/piston_engine_technology/power_and_torque.htm
I knew three data points, 0 rpm = 0 hp, max rated hp is 164 hp at 4400 rpm, and max torque is 258 lb-ft at 2200 rpm. I also used the following info from Carroll Shelby who dyno-tested a stock 260 engine and reported the results in Hot Rod Magazine, October 1963. Shelby reported the actual peak horsepower was 86% of the Ford-rated 164 hp. I converted Shelby's figures back to the rated figures by multiplying his figures by 1/0.89 so as to display the plotted curve in the Ford- rated values.

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BadBird
10-13-2015, 06:54 PM
Good info. 141 HP isn't bad for the stock 260. Even when my Falcon had the 260 it was fun to drive and had good pep. That is the way it was when we bought it for my son 23 years ago.
The next year in his automotive class he had to have a project so he put in a 302 with minor HP upgrades. It ran quite a bit better and in his high school drag races it did a little over 94 MPH with the C4 auto.
I knew we would never put that 260 back in the car, but we saved it for at least 15 years before I gave it to someone. It still ran good. The 260 is a great engine.
Larry

ew1usnr
10-13-2015, 07:18 PM
141 HP isn't bad for the stock 260.
Larry

Hello, Larry.

I like to use my Falcon as a measuring comparison when looking at new cars. The 260 was a big jump in technology when it was introduced in 1962, but a lot of progress has been made over the past 54 years.

Check out the torque and horsepower curves for a 2015 5.0L Coyote V-8 and a 3.7L Cyclone V-6. The engines are available in the 2016 Mustang. The Coyote puts out 435 hp and 400 lb-ft of torque. Yowsa!

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I love the name of the new 3.7L Cyclone V-6 engine. Here is a beautiful 1964 Mercury Cyclone:

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Luva65wagon
10-14-2015, 01:59 PM
Fun Facts! Dennis, you have too much fun with this stuff, I can tell.

[BOW]

One of the first 'car' motors I helped build (as a ~14/15 y.o.) was a '62 260 in a '62 Fairlane we had. The first motor I remember being engaged in building in general, was a flathead Ford tractor motor. I was about 11 then and the motor was "overhauled" as opposed to being rebuilt. It stayed attached to the tractor and we pulled the head and pistons, but not the crank. New rings and bearings and regasketed. My dad had me do all the "reach into small spaces" work. It was the building of these two motors, along with a few others, that got me hooked on mechanics at such a young age - and the rest is history. Also, the parts house/machine shop we used for all this work we did is where I would eventually go to work, while still in high school, prior to moving to Seattle 3 years later.

Not long after building the 260 it was the first car I drove long distance with my learners permit - from Sacramento to San Francisco - to drive my brother to a StarTrek convention. Pretty much its "break-in" trip. I remember that trip fondly. My dad said not to exceed 62 MPH. It was pretty peppy for a 2-speed slush-box.

My brother took possession of this car and drove it on into the early 80's until it eventually died of some unknown cause. No doubt, by now, it is a Toyota.

Wilbur
10-16-2015, 07:17 PM
I've got the little 260 V8 in my blue '64 Falcon, it's mated to the three speed manual transmission and the car has a fair amount of pull. I would not quite call the car fast but I won't call it slow, and it will put a grin on my face, not a belly laugh but a grin. When I one day have a place to store a spare motor I'll remove it and in it's place put a 302 or a 289.

Carroll Shelby extracted 260 horsepower from these little motors in his original Cobras, or maybe it was 306 hp, I've forgotten, but I recall he got a lot of power out of these motors before switching to the 289. I'm fairly content with the motor in my car so I have not modified it nor is it likely that I will, though I may put a better exhaust on it.

ew1usnr
10-18-2015, 01:34 PM
I read that Ford's goal for their first small blocks was to not build a powerful engine, but one that provided the smoothness of a V-8 while delivering fuel economy that approached that of a six cylinder.

They did a good job. My 260 idles so smoothly and quietly at red lights that I can barely tell that it is running. It delivers more than enough enough power to allow me to confidently accelerate up an interstate on-ramp and easily merge with traffic. Yea, buddy!

BadBird
10-18-2015, 06:53 PM
Speaking of interstate on ramps. That seems to be the only place I can really smash the go pedal on my Falcon. What is even better with 336 RWHP, 347 c.i. and dual carbs we found that my Falcon gets 17 mpg. That even includes the over 100 mph romps and burning tires on the interstate in Reno. Hope the cops don't read this forum.
The incredible Ford engines are absolutely made for fun, power and economy.
When we first bought this car for my son almost 20 years ago it had the 260 and he loved driving it.
He then put a mild 302 in during his high school automotive class for extra credit. It turned 94 mph in the high school drags that year with a C4 and stock tires.
The weight of these cars even with the 260 makes them a great driving and fun vehicle. Long live the 260. Larry

ew1usnr
10-20-2015, 06:44 PM
The weight of these cars even with the 260 makes them a great driving and fun vehicle. Long live the 260. Larry

Hello, Larry.

I'm not saying this to brag, but ...... I spun a wheel once this morning and twice this afternoon while driving to and from work. And without even meaning to, and with a Ford-O-Matic drive to boot!

This can be explained by my having little skinny 13-inch tires and not having a limited slip differential, but it still sounds impressive when one of the tires breaks free.

The 260 engine was rebuilt about 11,000 miles ago and it was really tight when I first got it back. As the engine loosens up it just keeps performing better and better and better. It really puts a smile on my face every time I take it out.

Luva65wagon
10-21-2015, 12:49 PM
Well, Dennis, I dare say you probably have more opportunity to drive yours than we do here in rainy Washington State. Assuming, of course, we get rain again. But usually when we do, these days, there is so much road oil laid down there is significant potential for spinning tires... and slipping tires.

:rain: