Horsepower And Classic Cars Meaning

 

During the time that I have been writing these posts I have received questions that were more general in nature than those that I usually answer. Rather than answer all these similar questions individually, I thought that it would be interesting to more fully explore some of these topics.

This post I am going to take one subject and look at it in more detail than usual. Hopefully, you’ll enjoy it. Depending on your feedback, I might continue this format in the future. This post’s topic is Horsepower.

The ability to move 33,000 pounds one foot in one minute. That is 1 HP. But I do not own any cars that weigh 33,000 pounds. The engine in a 1972 Cougar produces about 163 HP, so some simple math dictates that it should be able to move 5,379,000 pounds one foot in one minute. All my worldly possessions combined, including my house, don’t even come close to weighing over 5 million pounds, and I can’t imagine any situation in which I would need to move them one foot in one minute.

Horsepower is a measurement of work done over a period of time. In fact, the formula is HP = Work/Time. Going back to our original example, 1HP = Move 33,000 lbs. 1 foot (work) /1minute (time).

The amount of horsepower produced by the engines in our cars are measured on an engine dynamometer, but the dynamometer cannot measure horsepower directly. It must first measure torque, and then convert the torque to horsepower using the formula Torque x RPM / 5252 = horsepower. Using this formula, we see that an engine that produces 300 pound-feet of torque at 4000 RPM makes 228 HP, or 300 x 4000 /5252 = 228. Keep in mind that as the RPM changes, so does the torque, and therefore, so does the horsepower. So, it is a little misleading to say that an engine makes 300HP, or 400, or 500. All engines make different amounts of horsepower at different RPMs.

Which leads me to my next point. What does all this mean, and how does it relate to the performance of our classic cars?

I think that most of us understand that, in general, the more horsepower any given car has, the faster it will be. But it is not that simple.

Let us take a make-believe 1970 Camaro with a 300-horsepower engine. Do not forget that it only makes that 300 horsepower at a specific RPM. The RPM at which it makes the three hundred horsepower is dependent on many different variables including, but not limited to the engines bore, stroke, camshaft profile, intake and exhaust design, and compression ratio. The variables are determined by the manufacturer, or engine builder depending on the performance needs.

If the Camaro is going to be raced at a dragstrip, it will need to make as much horsepower as possible very low in the RPM range because the car will be starting from a standstill every time it races. If it will be raced on a road course, the engine will need to be built in such a way as to make the maximum horsepower in the middle and upper RPM ranges because that is where the engine will be operating during most of the race.

Suddenly it becomes apparent that the published horsepower figures that we see really mean very little. A simple graph showing how much horsepower an engine makes as the engines RPM increases would be much more useful, and that is exactly the information that a “dyno chart” provides.

Now that we are all experts on horsepower, forget everything I just told you, because during the time that our classic cars were built, the manufacturers umm…err, fibbed when it was convenient for them.

During the “horsepower wars” of the 1960’s, manufacturers could get higher horsepower figures by stripping the test engines of accessories such as alternators, or even water pumps! The engine only had to run for a short time. This backfired when the insurance companies noticed some very high horsepower figures, and perceiving a higher risk, they charged a higher premium, resulting in decreased sales for the manufacturers. To reverse this loss of sales, the manufacturers went in the opposite direction by under-reporting actual horsepower figures and leaving it up to buyers to look at test reports in the enthusiast magazines of the era. An example of this would be the 1969 Camaro Z-28 or the 1969 Boss 302 Mustang. It is generally accepted that the reported horsepower of both of these engines was grossly underrated at only 290 horsepower.

Finally, in the early 1970s the SAE (Society of Automotive Engineers) stepped in with standardized test procedures and horsepower ratings were more consistent.

So, what does all this mean? Nothing. Unless you are a professional racer or engine builder because you cannot really feel horsepower. The force that pushes you back in your seat when you step on the gas pedal is the “torque” that the engine produces. But that is a story for another day.

 

Classic Cars: Buy What Feels Right

 

I get to drive a lot of classic cars, and one of the things that never ceases to amaze me is how few of them “just feel right.” There is absolutely no relationship to how much money may have been spent on a restoration—or how little, for that matter.

I will occasionally have a conversation about this subject with colleagues or friends, and they know what I am talking about. But most people simply do not understand.

This most often happens when I am inspecting a car for a prospective buyer. I will give the client a written report extolling the virtues of the subject car. Pages and pages of how the car was taken off the frame and every single suspension part replaced, whether it needed to be or not. The acres of flawless leather upholstery, and the paint that is flawless. I will usually continue with a description of all the documents and receipts for the parts and labor, which will often exceed the cost of a new home.

I get to the part where I give my opinion as to how the car feels when you drive it, which is something very subjective indeed. And very often I must end my report by stating that this expensive masterpiece of a restoration, something that is cosmetically and mechanically far better than new, “just does not feel right.” Naturally when my customer receives the report, the first response is “How can this be?” And the truth is, I have no answer. I explain that I do not mean to imply that the car does not drive well, or handle well, or steer well, or stop well. In most cases it does. But still, it just does not feel right. I suppose that what I am trying to say is that it does not feel the way that it did when it was new.

This brings me to my next point. How do I know what it felt like when it was new? I came of age during the time that many cars that are now considered collectible were new or so. I also seek out and collect “survivors.”

Although this term is bandied about to include about anything that is not restored, including junk, my definition is a bit more discerning. I believe that a survivor must be in excellent, unrestored, original condition, including drive train, paint, and interior. But I go one step further. It must have exceptionally low mileage, usually not more than 20,000. This last criterion is what makes it possible for the car to not only look right, but also feel right. In effect, what I look for is what would have been advertised as a “low mileage used car in excellent condition” 40, or 50 or 60 years ago.

As it turns out, I am not the only one who appreciates this virtue. Survivors are one of the hottest segments of the collector car market. When you ask someone why they collect survivors, the number one answer is “they just feel right.” The number two answer is usually something like “they’re only original once.”

Survivors are in tremendous demand, sometimes with equally tremendous premiums. I find it interesting that the attribute that makes them so desirable is virtually unquantifiable. How do you define “just feels right”? It means that the car feels the way that it did when it was new. No better. No worse.

Worse is extremely easy to achieve. It can be accomplished by ham-fisted mechanics, ordinary wear and tear, and the use of improper or inferior parts.

Better is also easy to achieve, thanks to talented mechanics as well as parts and materials that are superior to those that were available when the car was new. It is exceedingly difficult to achieve that “just right” feeling, and that is why collectors are willing to pay a premium for a survivor.

That is not to say that “it just feels right” cannot be achieved. There are restoration shops across the country, and around the world - usually marque specialists that have spent decades learning how to make cars “just feel right.”

The wait to get a car into one of these shops will often be measured in years, and you should be prepared to have an open checkbook. You would be surprised how many cars that “just feel right” were restored in a collectors’ garage. The amount of time and love that these experts have lavished on cars cannot be translated into dollars, but they can sometimes be translated into the way driving a car feels.

Occasionally I will see a collector walk away from purchasing a concours-quality restoration. I will ask why, and the collector will respond “it just didn’t feel right.” That impresses me.