By David Reher, Reher-Morrison Racing Engines
“An engine is never worth more than when it’s assembled and running.”
Anyone who flies enough miles in airplanes or stays enough nights in hotels eventually qualifies for “free” upgrades. Of course, these upgrades come with a price – they’ve been paid for with time, money and the aggravation of life on the road. With a new racing season about to begin, many racers are thinking about upgrading their engines – but like first-class seats and hotel suites, there’s a price to pay for an upgrade.
It’s the nature of racers to want to go faster, so I’m often asked what can be done to “hop up” a used engine to make it more powerful. Unfortunately, if an engine is a well-developed combination (rather than a collection of uncoordinated parts), then the true cost of a significant hop up is almost always unreasonable.
That statement certainly requires an explanation. We consider three important factors when we develop a sportsman engine combination at Reher-Morrison Racing Engines: performance, price, and reliability. I think most racers make their decision to purchase an engine on a similar basis, balancing their ambition to go fast with their budget. If the goal is to run 10.90, it doesn’t make sense to buy a nitrous-injected, 1,800-horsepower, 632cid engine. On the other hand, a racer isn’t going to qualify for many six-second Top Sportsman shows with a 600hp/468cid big-block. The calculation eventually comes down to this: How fast do you want to go, how much do you want to spend, and how willing are you to maintain the engine?
Obviously no one would reasonably try to “hop up” a 468cid big-block into a 632 Mountain Motor. About the only part that would carry over in such a conversion is the distributor hold-down stud. But what if a racer is looking for a 200-horsepower tune-up? Surely that’s not difficult, is it?
Well, in fact it is in most instances. Recently we’ve been spending long days on the dyno developing new sportsman engine combinations. And while we’ve certainly made improvements, the one point that stands out when I look at the dyno sheets is how refined these combinations have become. Changing a cylinder head port or swapping a camshaft seldom produces a big change in performance – and there is always the risk that a new part could jeopardize long-term reliability.
I think the notion of an easy, bolt-on hop-up is a carryover from the days when the selection of parts for sportsman racers was limited. When I started drag racing nearly 40 years ago, there were three national TV networks (ABC, CBS, and NBC) and two popular racing engines (Chevrolet small-block and big-block V-8s). Now there are more than 200 channels on my television, and a staggering number of racing engines. Times have certainly changed.
We still call these engines “big-block Chevys,” but they have virtually nothing in common with their predecessors. Think about all of the differences: deck heights, bore spacing, camshaft locations and diameters, oil pan rails, head bolt patterns. Most important are the dozens of cylinder head designs that are now available: siamesed port, spread port, and symmetrical port – each with specific valve angles, guide spacing, port locations, runner heights, valvetrain components, bolt patterns, and so on.
How did this explosion happen? Engine building underwent a profound change in the 1980s when aftermarket manufacturers such as Dart, Brodix and others began to produce cylinder heads. Before then, racers were utterly dependent on Detroit for parts. We hung on the rumors that there would be a new angle-plug cylinder head or a new Bow Tie casting. We couldn’t wait to get the latest California intake manifold. But the game changed radically when the aftermarket manufacturers learned how to produce and machine their own castings. Suddenly engine builders could get Pro Stock-style heads without the headaches and hassles that came with welding, machining and modifying OEM parts. We learned how to make our own manifolds from a sheet of aluminum. The genie was out of the bottle.
The result is that we are now living in a Golden Age for sportsman drag racers. The parts that are now available are incredibly good. I’ve often thought about just how competitive a 500cid big-block built with a Dart block and set of our 12-degree Raptor spread-port heads could be in Pro Stock – I think we’d have won some races not too many years ago with a combination like that!
The downside is that changing one part now affects dozens of other components. For example, upgrading a big-block V-8 from conventional siamesed-port heads to a spread-port design requires much more than bolting on a new set of heads. The conversion requires new pistons, new rocker arms, new pushrods, new valve covers, and new headers. The block’s lifter bushings really should be bored and bushed to accommodate the new pushrod geometry, and the camshaft should be changed to optimize airflow. Of course the engine will make more power and higher rpm, so the oiling system needs to be upgraded as well.
At this point, a racer is simply better off to buy a new engine with the desired power level rather than hopping up an existing engine. An engine is never worth more than when it’s assembled and running. It has value as a spare or as a complete motor that can be sold to another racer. I know that racers often have good intentions to reuse the parts that are stripped off an engine during the upgrade process, but my experience tells me this seldom happens. Usually a racer ends up with a pile of expensive parts sitting on his garage shelves that lose value with every passing day.
When a perfectly good racing engine is disassembled and its parts scattered in the pursuit of a performance upgrade, it’s seldom an economically sound solution. As the song says, you don’t know what you’ve got ’til it’s gone.