By David Reher, Reher-Morrison Racing Engines
“Why does an engine with standard parts run better than one with all of the latest tricks, gizmos and gadgets?”
Sometimes technology can go too far. I recently purchased a cell phone that came with an instruction manual as thick as a brick. I use a telephone for one reason: to make calls. I didn’t buy a cell phone to play video games, take fuzzy photographs, download disco music, get directions to my house or monitor the stock market.
By David Reher, Reher-Morrison Racing Engines
“I’m excited about the emerging trend toward fast sportsman drag racing.”
Looking back at the 2004 season, I can attribute much of the performance improvement in Pro Stock to faster engine speeds. It’s difficult to believe that 500cid Pro Stock engines now routinely turn 10,000 rpm, but the truth is plain to see on the data recorders and on the time slips.
By Darin Morgan, Reher-Morrison Racing Engines
DARIN MORGAN, author of this issue’s Technically Speaking column, is in charge of cylinder head research and development at Reher-Morrison Racing Engines.
“Comparing the Space Shuttle to a racing engine may seem like a leap, but in fact the underlying variables in an engine combination are equally mind-boggling.”
With four national events in four weeks, including two round trips to Maple Grove Raceway, David Reher has been spending more time sitting on airplanes than on writing his column for National DRAGSTER. David asked me to pinch hit for him in this issue, and since my subject is computer simulation, you might think of this as a simulated David Reher article.
Engine simulation software is a hot topic in the automotive industry. Sophisticated programs such as WAVE and MANDY cost millions of dollars, which limits their customer base to auto manufacturers and Formula 1 teams. For the rest of us, there are engine simulation programs with prices that range from less than $100 to several thousand dollars.
I admit that I’m addicted to engine simulation software. I’ve played with numerous programs, and I’ve spent hours running “what if?” scenarios. But as a professional engine builder, I also understand the limitations of these programs. Unfortunately, some racers don’t.
In my conversations with simulation software designers and code writers, I’ve learned that these programs were never intended to design an entire engine. Rather, their primary objective is to note specific trends of individual changes. In other words, a program can tell you with reasonable accuracy what the likely result will be if you change the bore, stroke or runner length in a Corvette LS1 engine. It can’t tell you how to build a Quick 16 engine from scratch.
My specialty at Reher-Morrison Racing Engines is cylinder head development. I’m frequently asked about equations or formulas that can determine specific engine design criteria. Customers want to know how to calculate the perfect port volume for an engine, how to select the ideal intake manifold, or how to determine the optimum valve diameter for a runner. They want a magic formula that explains how a racing engine works – but such a shortcut simply doesn’t exist.
Consider the Space Shuttle. It’s just an airplane with rocket motors, right? But when you look into the details of launching, flying and recovering the Shuttle, it becomes apparent that this is a task of mind-boggling complexity. The variables are almost infinite.
Comparing the Space Shuttle to a racing engine may seem like a leap, but in fact the underlying variables in an engine combination are equally mind-boggling. If you don’t understand what these variables actually do, it’s tempting to plug numbers into a simulation program until you get the results you want. One likely consequence of this approach is to design an engine that’s not applicable in the real world.
Here’s an example. Recently a racer questioned me about all of the components in one of our Super Series bracket racing engines. I gave him the information he requested, and he modeled the engine with a simulation program. His results were fairly accurate, with an error of about 2.5 percent (20 horsepower), which I thought was reasonable. But the software stated that if the exhaust duration were increased 10 degrees, the engine would gain 25 additional horsepower. I just wish it were that easy!
We’ve built and dyno tested dozens of these engines. They’ve logged thousands of runs on drag strips. Now a customer tells us that we left 25 horsepower on the table. But what the simulation software didn’t allow him to do was input the discharge coefficient of the exhaust port. In other words, the program didn’t “know” the design specifics of the exhaust system. It based its calculations on simple airflow, and therefore didn’t have enough information to generate a realistic answer.
You still need experience and knowledge to get it right. The more complicated the software, the more essential this real-world database becomes. When dealing with ultra-high performance engines, the details become so subtle that no software can simulate them. In a high-end racing engine, a tiny change in the approach to the valve seat or the contour of a piston dome can produce a measurable difference in performance on the dyno and on the drag strip. Even Ferrari, with its whiz-bang Formula 1 simulation software, still has to build, test and validate any change in hardware before taking it to a race.
It’s a mistake to put blind faith in a computer program. Some programs are certainly more accurate in their predictions than others, but they all have shortcomings. Building an engine on a computer screen is no substitute for bolting together the parts and running it down a track. To my knowledge, a virtual engine has never won an NHRA national event.
By David Reher, Reher-Morrison Racing Engines
“A little oil consumption is a good thing because it indicates that you’re right on the edge of the minimum required ring tension.”
I’m told there is no free lunch, but I am certain there is free horsepower to be found in many racing engines. What I define as free horsepower is increasing an engine’s output by reducing parasitic losses such as oil windage and internal friction. Piston rings and oil systems are two interrelated areas where you can often find horsepower without changing the basic engine combination.
By David Reher, Reher-Morrison Racing Engines
“Some racers wear out the threads on their carburetors trying to adjust for weather conditions.”
As I write these words, we’re loading our Speedco Pontiac Grand Am into the transporter for the annual trek to Denver. Preparing to race at a mile above sea level brings home the reality of racing under adverse conditions. While we make many adjustments for Bandimere Speedway, one of the items that is definitely not on our to-do list is to change carburetor jets.
By David Reher, Reher-Morrison Racing Engines
“A low-tension valve spring and a heavy steel valve is the worst possible combination for high-rpm reliability.”
Faithful readers of this column know that my mantra on engine building is to spend your money wisely. Sometimes that means writing a bigger check initially in order to save money in the long run. A case in point is the decision whether to use flat tappets or roller lifters. In my view, a flat tappet is a ticking time bomb in a racing engine. Sooner or later, that bomb is going to explode with expensive results.
By David Reher, Reher-Morrfison Racing Engines
“The valve spring is like a canary in a coal mine – it will usually signal a developing problem before a catastrophic failure.”
When Galileo pointed his handmade telescope at the planets and became the first human to behold Jupiter’s moons and Saturn’s rings, he saw something that had been invisible. Of course these moons and rings had existed for millenia, but they were beyond human perception until the invention of a device that could magnify the faint images. Like Galileo’s telescope, tools such as dynamometers, wet flow benches, and data recorders have given drag racers the ability to “see” events that would otherwise be imperceptible to human senses.
By David Reher, Reher-Morrison Racing Engines
“Not everyone may agree with our technique, but I am convinced that it is the best way to achieve accurate results.”
With apologies to my sister the veterinarian, there is more than one way to skin a cat and more than one way to measure piston-to-valve clearance. I’m not an authority on cat skinning (nor do I want to be), but I do know about the importance of proper valve clearance in a racing engine. I see hundreds of engines come through our shop every year, and I’m alarmed by how many engines assembled by do-it-yourself builders have incorrect piston-to-valve clearance.
DARIN MORGAN, author of this issue’s Technically Speaking column, is in charge of cylinder head research and development at Reher-Morrison Racing Engines.
“We felt like blind men who had been given the gift of sight.”
If you expected to find David Reher’s column on this page, I hope you won’t be too disappointed to find my words here instead. I’m in charge of cylinder head development at Reher-Morrison Racing Engines, and David asked me to write about the extraordinary impact of wet flow testing on our R&D program. I’ve given presentations on our wet flow development at the Performance Racing Industry (PRI) trade show and the Advanced Engine Technology Conference. Since most National DRAGSTER readers can’t attend these events, David thought that Technically Speaking would be a good way to spread the news. He also promised that he’d be back on this page in a few weeks.
By David Reher, Reher-Morrison Racing Engines
“Building a racing engine is like painting a car – the preparation takes far longer than the final act.”
Walking through the aisles in a supermarket can teach you more about marketing in the 21st century than a business school textbook. It’s easy to see the hot buttons that the experts have determined will trigger a purchase decision for anything from breakfast cereal to dog food: “New!” “Improved!” “Natural!” “Low Fat!” “Low Sodium!” shout the packages. It takes a skeptical consumer to recognize the hype behind the words. Yes, a tin of lard is low sodium; that’s because it’s pure fat.
By David Reher, Reher-Morrison Racing Engines
I couldn’t tune a piano if my life depended on it, but I have tuned a few engines in my career. The process of tuning is fundamentally the same for racing engines and musical instruments. In both cases, you are making the final adjustments to a complex assembly of precision components. No one tunes a piano with a hammer, but sometimes I see racers take a sledgehammer approach to tuning engines.
By David Reher, Reher-Morrison Racing Engines
I believe that an informed customer is a better customer. Whether I’m buying a laptop for my daughter to take to college or a new CNC machining center for our shop, I like to know as much as possible about the product before I sign on the dotted line. So in this spirit of full disclosure, I’m going to tell you something you need to know about racing engines: The more powerful the engine, the more maintenance it requires.
By David Reher, Reher-Morrison Racing Engines
“A dry-sump oil system is one of the few products you can buy with confidence that it will improve performance.”
According to the informal David Reher telephone poll, interest in fast Sportsman classes is skyrocketing. If the sample of racers I talk to is representative of the sport as a whole, then Top Sportsman racing has a bright future. Interest in this particular style of fast doorslammer racing is spreading as quickly as a rumor on the Internet. The fact that Top Sportsman has been adopted by several NHRA divisions is a leading indicator of the class’ future growth.
By David Reher, Reher-Morrison Racing Engines
Has the world really become a more dangerous place, or are we just more aware of the dangers of everyday life? If I buy a new appliance, a power tool or a treadmill, the owner’s manuals typically have dozens of pages of warnings, cautions, disclaimers and notices before I ever get to the instructions. There are enough stickers in my truck warning me about the possible dangers of air bags, roll-overs and exploding batteries to make me think that driving to work should qualify as hazardous duty. But ironically, the more we are assailed by warning signs, screaming yellow caution notices and clever icons depicting various ways that stick people can be killed and maimed, it seems the less attention we pay to them.
By David Reher, Reher-Morrison Racing Engines
A strong, dependable block is the cornerstone of every racing engine. It’s the foundation that supports all of your efforts to build horsepower. Yet as important as the block is in building a reliable and powerful motor, too many racers still insist on using a “good old block” as the starting point for a competition engine. In my opinion, that’s a major mistake. The truth is that there aren’t any good old blocks – at least when the subject is big-block Chevrolet V8s.
By David Reher, Reher-Morrison Racing Engines
In the drama of drag racing, drivers are the stars and engine builders are the extras. I understand why the Best Actor at the Academy Awards gets his picture on the front page while the camera operator gets a mention in the final paragraph. After all, no one interviews the winning engine after a final round; it’s the drivers who get (and deserve) the glory.
By David Reher, Reher-Morrison Racing Engines
When I first discussed writing the Speed Reading column with the staff at National DRAGSTER several years ago, we agreed that I would focus on engine technology for sportsman racers. At the risk of pushing the editorial envelope, this month I’d like to expand my assigned topic with some thoughts on how chassis and car setups affect quarter-mile performance.
By David Reher, Reher-Morrison Racing Engines
The 21st century has been called the Information Age, but I’m beginning to wonder whether it might be more accurate to call it the Infomercial Age. The advent of long-format television commercials has blurred the distinctions between advertising and reporting. If the production is slick enough, it’s difficult to discern the difference between a sales pitch and a documentary.
By David Reher, Reher-Morrison Racing Engines
It’s the nature of racers to work on things – even parts that may be better left alone. Ingenuity and experimentation have produced power levels that were once thought to be impossible. As a lifelong tinkerer, I confess that I find it hard to resist the urge to mess with mechanical components. Nevertheless, I strongly urge you to resist the temptation to service the valve seats in competition cylinder heads.
By David Reher, Reher-Morrison Racing Engines
“Almost without exception, engine problems are the result of insufficient clearances.”
We are often told to think big if we want to achieve success, but today I want you to think small. In fact, I want you to think about clearances in a racing engine that are smaller than one thousandth of an inch. These minuscule measurements can mean the difference between long life and sudden death for a racing engine.
By David Reher-Morrison Racing Engines
The road to high technology is often a two-way street. People who are involved in motorsports maintain that racing improves the breed, from the invention of the rearview mirror by Ray Harroun, the first Indianapolis 500 winner, to the disc brakes and low-profile tires that are commonplace on cars today. But the improvements that are made on everyday automobiles and trucks can pay dividends for racers, too. The extended lifter bosses in the sixth-generation (Gen VI) big-block Chevrolet V8 are an example of production engine technology that has benefited hardcore drag racers.
By David Reher, Reher-Morrison Racing Engines
According to the calendar on my office wall, this is my last column of the year for National DRAGSTER. It’s true: Time does fly, whether or not you’re having fun.
Ten months ago, Bruce Allen and I were preparing our new Pro Stock Grand Am for its maiden run. Now both the car and the crew are showing the effects of a long season that seemed to pass in a blur. Fortunately, 2001 has been a rewarding year for the Reher-Morrison team, and I’m already making plans for next season.
By David Reher, Reher-Morrison Racing Engines
If a generation is roughly 25 years, I calculate that our sport is about to see its third generation of racers pull into the staging lanes. As NHRA celebrates its Golden Anniversary season, I’m grateful for the improvements in the quality of parts that the first two generations of racers have produced.
When I started racing years ago on dusty Southwestern drag strips, we expected to break parts. My friends didn’t ask me on Monday morning, “Did you win?” Rather, they wanted to know, “What did you break?” The station wagon rearends, junkyard 4-speeds and oddball parts that were the staples of our so-called racing program were the strongest pieces we could pull out Texas salvage yards – but they still couldn’t withstand the unreasonable demands of a bunch of neophyte drag racers.
By David Reher, Reher-Morrison Racing Engines
What’s wrong with this picture? I am walking through the staging lanes at high noon on a sweltering summer day. All around me people are wearing shorts and T-shirts, with wet shop rags wrapped around their foreheads to keep the heat at bay. Super Comp drivers sit in their dragsters with umbrellas strategically placed to ward off the sun, while electric fans circulate the heat inside a dozen Super Gassers like convection ovens. As I head toward the starting line, I hear engines running on all sides as racers warm up their engines.
Wait a minute! It’s hot enough to cook an omelet on the starting line, so why are drivers warming up their engines?
By David Reher, Reher-Morrison Racing Engines
There seems to be some confusion about the true purpose of the lubrication system in a racing engine. The primary purpose of the oiling system is to lubricate the engine – period. It is emphatically *not* the place to look for horsepower in a bracket racing motor with a wet-sump oil pan.
Think of a sportsman drag racing engine as an endurance motor. It may only run at maximum power for a few seconds at a time, but those runs add up over a long season of racing. If you are a serious sportsman racer, you need an engine that can make 300 to 400 passes without looking at the bottom end. From my perspective, that’s the equivalent of running a 500-mile Winston Cup event or a 24-hour endurance race.
By David Reher, Reher-Morrison Racing Engines
“I am convinced that the two most misunderstood words in engine building are ‘bolt on’.”
According to my sister, a veterinarian, all dogs are descended from a common ancestor. Every member of canis familiaris, also known as the domestic dog, can trace its roots to grey wolves that walked the earth 14,000 years ago. This means that Duke, the chocolate Labrador retriever who rules the Reher household, belongs to a family that also includes yappy miniature poodles, towering Great Danes, and every mutt at the Humane Society.
By David Reher, Reher-Morrison Racing Engines
As Reher-Morrison Racing Engines has evolved over the years, I have seen the differences between Pro Stock and high-horsepower sportsman engines become less discernible. Once upon a time, there was a common belief that some parts were just too exotic for sportsman-type engines. When my friends and I built small-blocks in the back room of an auto parts store in 1972, we thought that roller cams and custom pistons were wildly sophisticated. Now, of course, such components are commonplace in every eliminator.
By David Reher, Reher-Morrison Racing Engines
Economists and stock market analysts look to leading indicators to divine the future, but I have discovered a more accurate way to predict what will happen. I simply listen to my customers. The trend is clearly toward bigger, more powerful engines for all types of sportsman racing.
I can say categorically that interest in bigger engines is expanding (pardon the pun). While a 502 or 522-cubic-inch engine was once considered a big-inch powerplant, I now frequently field calls from racers asking about 615 and 632-cubic-inch motors. With the introduction of a new generation of Pro Stock-style CNC-ported cylinder heads, horsepower levels are climbing faster than the cost of electricity in California.
By David Reher, Reher-Morrison Racing Engines
It’s often said that the only difference between men and boys is the price of their toys. Forty years ago, I earmarked the profits from my newspaper route to buy a new bicycle; today I can hardly wait to pick up my new 2001 Pro Stock Grand Am. I tell my accountant (and my wife) that a new race car is really an investment, a tool to promote our business and to keep Reher-Morrison Racing Engines on the leading edge of engine development. But just between you and me, I wouldn’t be gearing up for 24 weekends on the road next year if I didn’t enjoy racing.
By David Reher, Reher-Morrison Racing Engines
I come from a family of teachers, so I suppose it was inevitable that I would end up standing in front of a classroom. My father lectured on economics, but my specialty is racing engines. I thought I knew that subject well – until my students asked questions that I couldn’t answer!
This year we’ve hosted a series of Reher-Morrison Racing Engine Schools at our shop in Arlington, Texas. It’s rare to have a weekend when Bruce Allen and I aren’t racing or testing our Pro Stock Firebird, but I’ve found myself looking forward to the classroom sessions. A recent group of students who came for a two-day class was really into internal combustion, and their enthusiasm renewed my interest in parts and pieces that I’ve worked with for years.
By David Reher, Reher-Morrison Racing Engines
There is a rule of thumb in the computer industry that speed and memory double every six months – at half the price. Alongside today’s Pentium processors and mega-gigabyte hard drives, the personal computers and that were state-of-the-art a few years ago now seem like steam-powered antiques.
The PC revolution has had a huge impact on drag racing – and not just in data acquisition systems and weather correction programs. The development of powerful mini-computers has dramatically cut the cost of horsepower by making sophisticated CNC (Computer Numeric Control) machining readily available. The result: Racers get more bang for their bucks than ever before.
By David Reher, Reher-Morrison Racing Engines
I am neither a golfer nor a golfing fan, but even I have heard about Tiger Woods. It seems there isn’t a national magazine, television news program, or newspaper that hasn’t featured golf’s latest multimillionaire. Woods’ success on the links has brought even greater success on his business ledger, with personal endorsements for everything from credit cards to sport shirts.
I know that buying a set of Tiger Woods golf clubs will not make me as good a golfer as he is. I have no illusions that owning a Mark McGwire baseball bat or a Michael Jordan basketball will make me a sports superhero. Unfortunately, some racers don’t understand that buying the parts used by successful drivers does not guarantee a place in the winner’s circle.
By David Reher, Reher-Morrison Racing Engines
Our era is often referred to as the Information Age, but not all of the available information is necessarily useful. I am beginning to think that flow benches should be labeled with a government warning: “Caution! Excessive reliance on flow numbers may be harmful to your engine!”
I’m kidding, of course. Used wisely, a flow bench can be a useful tool in engine development, just like a timing light or a dynamometer. Unfortunately, some racers believe that a flow bench is the ultimate answer machine.
By David Reher, Reher-Morrison Racing Engines
Recycling is unquestionably good for the health of planet Earth, but it is risky when you are building a race engine. My environmentally conscious teenage daughter has impressed on me the importance of recycling soft drink cans and newspapers for the good of future generations. The motivation to reuse race engine parts is usually financial, not ecological. I think it’s just bad business to reuse engine parts that are mismatched, outdated, or just plain worn out in the hope of saving a few dollars. Usually it turns out to be more expensive in the long run, and the results are seldom what you expected.
By David Reher, Reher-Morrison Racing Engines
What drives a person to want to race? There are certainly less stressful, less expensive, and less tiring ways to spend a weekend. While some people are content to channel surf or grow roses, I’ll wager that the readers of National DRAGSTER have a different idea about the best way to occupy their time.
People race for a variety of reasons. For some, racing is a business – a fortunate few are actually paid to drive race cars, or they earn a living from the sport as a parts manufacturer, engine builder, mechanic, or some related occupation. Others participate because they relish the challenge of competition or the rush of driving a fast car. Racing can be therapeutic, too – a welcome escape from the daily grind of deadlines and minor aggravations.
So if racing fills so many needs, why do I encounter such unhappy people at the races?
By David Reher, Reher-Morrison Racing Engines
The signs of spring are unmistakable: flowers are blooming, basketballs are bouncing in the playoffs, and race car exhausts are booming. Racers are shaking off their winter doldrums, and race cars are coming out of hibernation in unheated garages and shops. But before you rev up for the new season, it’s essential to clean the cobwebs out of both your brain cells and your race car.
Racers have a tendency to focus on high-tech equipment, but this is the time of year to pay attention to the basics. Even the most sophisticated computers operate on a very simple binary system: they reduce the universe to ones and zeroes, to “Off” and “On.” A computer can tell you the driveshaft rpm at every millisecond during a run, but it can’t tell you why your engine is popping and banging at the top of low gear. That’s something you’re going to have to figure out using your analog human brain.
By David Reher, Reher-Morrison Racing Engines
At the 1968 Summer Olympics, gold medal winner Bob Beamon soared 29 feet in the long jump – a leap nearly 3 feet longer than the previous record. Beamon excelled in jumping across a sand pit – but if jumping to conclusions were an Olympic event, I have no doubt that a drag racer would win the gold.
Jumping to conclusions is an occupational hazard in racing. We want our cars to run faster, more consistently, and more successfully. The pressure to perform is intense, and often we allow our emotions to overrule our common sense.
By David Reher, Reher-Morrison Racing Engines
Although the title of this column is “Technically Speaking,” I’m going to stray from my usual nuts-and-bolts topics for this final column of the year. I’d like to comment on the only subject that concerns racers more than horsepower: money.
My fellow back-page columnist Ken Owen can certainly write with authority about the evil produced by the love of money. Our parents told us that money can’t buy happiness, and the Beatles sang to us that money can’t buy love. I’m going to add another item to the list of things that money can’t buy: success in racing.
I know that deep pockets are better than empty pockets. But I also know that without desire and determination, money is like gold plating – flash without substance.
By David Reher, Reher-Morrison Racing Engines
You won’t see my name alongside Stephen King and Tom Clancy on the list of best-selling authors, and my book is not likely to be reviewed by the New York Times. Nevertheless I’m very proud to have joined the ranks of professional writers. When the first bound copies of the two-volume Reher-Morrison Engine Assembly handbooks arrived at the shop, I felt the same sense of accomplishment that I get when we fire a new engine on the dyno for the first time.
I really can’t take credit as the sole author of this work. Like the Encyclopedia Brittanica and the Bible, the 433-page Engine Assembly books were a collaborative effort, albeit on a much smaller scale.
By David Reher, Reher-Morrison Racing Engines
I haven’t checked the Environmental Protection Agency’s list of endangered species recently, but I’m willing to bet that the small-block V8 is on the list. While the small-block is still the engine of choice in oval track racing and several NHRA sportsman eliminators – notably Stock, Super Stock, Competition, and Pro Stock Truck – the big-block V8 has simply taken over the heads-up eliminators and fast brackets.
There is a reason why the Rat motor reigns as the king of the quarter-mile: the big-block Chevy is durable, heavy-duty, and the best bargain in motor racing.