One of the pillars of the classic track car community is the engine swap. This instant cure-all can go a long way towards eliminating the questionable reliability of certain past-tense power plants, while simultaneously injecting a substantial performance boost (at a price that's occasionally less than what building the original motor would cost).
Swaps make a lot of sense, especially for those who drive vehicles where parts availability has dwindled to a handful of remanufacturers or rapidly-disappearing piles of used spares. It's also hard to deny that the engine bays of certain models—such as my own Datsun Z—feature the kind of voluminous, inefficient use of space that defined the production capabilities of their day, allowing them to readily accept a wide variety of naturally-aspirated and turbocharged setups.
In fact, the Datsun community is the perfect example of engine swaps run rampant. So many Z owners have taken it upon themselves to install a time portal under their hoods that I'd wager roughly half of the people who approach me at a track day assume that I'm running something far more exotic than my near-stock period setup. The surprise that registers across their faces when I pull back the bonnet to reveal my modest L28 inline-six—rather than a turbocharged RB25DET, SR20, or LS V-8—is something I never tire of witnessing.
Why haven't I jumped onto the engine surgery express? It turns out that sports car swap politics are surprisingly nuanced, especially at the race track, making it more difficult to divide along “purists vs. hot rodders” lines that so often trip us up on the grounds of the local concours.
First, it would seem that modernizing the peripherals of a classic in the pursuit of better durability, improved safety, and enhanced performance is a far less charged path to take than transplanting an aging ticker for a mechanically-superior set of ventricles. You'd be hard pressed, for example, to find drivers vociferously defending the virtues of using period-correct tires and brake pads on a race track the same way traditionalists wax philosophical about the experience of a finely-tuned triple-Weber carb setup. At the show ‘n’ shine, anyone running a set of Koni adjustables on their Triumph is a heathen, but at the track, they're a savant.
The take-away from this could be that a classic's engine is the embodiment of its soul, and to excise its original drivetrain is to exorcise the spirit that makes it special. I'm almost tempted to buy in on this point of view, were it not for the bevy of beautiful automotive designs handcuffed to uninspiring agricultural engines foisted on them by the economic and engineering realities of their era, or the long list of lithe chassis anchored by the same.
Does replacing an Italian V-12 with a pushrod V-8 dramatically change the personality of an automobile? Without question—but the same could be said of pulling the Iron Duke out of a Camaro. Some motors simply don't warrant preservation at all costs, and to view a vehicle as irrevocably sullied by the presence of an engine it didn't leave the factory with is a fairly narrow point of view to adopt, especially when you're not the one forced to truck along a metric ton of spares to survive a weekend on a road course. Is it any more a simulation of the classic experience to hit the throttle on an electronically-controlled twin-turbo engine than it is to ride on a rigorously updated modern suspension setup riding under a antique shell?
I've been lucky with my 280Z. The engine is dead reliable, easy to work on, and comes with strong parts support. It also happens to be fuel injected from the factory—an emissions-fighting step Datsun took towards the end of the S30 Z car's run—and even though its electronic brain could be defeated in a game of chess by a Casio digital watch, it's still smart enough to outwit vapor lock on the hottest of summer afternoons. As I've written in the past, I'm on the track for the experience of piloting an old car to the limits of my own abilities, not taking home FTOD, and within that context the L28 provides me with enough power—and of course, that glorious straight-six clarion call—to distract me from thoughts of more modern temptations.
Not everyone's classic is quite so pliable to the demands of on-track abuse. For every individual enthralled with the fetching lines of a 40- or 50-year-old sports car, there's another who's unwilling to endure spending more time under, than inside, said vehicle during the course of a weekend. If a swap allows someone to actually drive an automobile that would otherwise sit fallow in a garage on the weekend, then it's difficult to argue against modern motivation—and it's even less polite to do so when you smell like a mixture of gas, oil, and uncatalyzed exhaust fumes, like I do at the end of a session.