Things that go VROOM ... đź’¨


"A man with no vices is a man with no virtues"


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I read something about that engine a few years ago

More than 70 years ago, Zora Arkus-Duntov and his brother, Yura, developed the hemispherical overhead-valve cylinder head for the Ford Flathead. Known as the ARDUN head, it radically altered the performance capability of the engine, offering a dramatic increase in horsepower that was due not only to greater airflow, but an increase in the effective engine speed, which allowed it to make more power at high rpm.

It's that same quest for high-rpm horsepower that pushed Mercury Racing (a division of Mercury Marine) to develop the SB4 7.0 engine; an automotive crate engine that, in a nutshell, uses a GM LS foundation (the LS7 cylinder block) with an all-new, custom-designed set of four-valve, dual-overhead-camshaft cylinder heads.

The result is a naturally aspirated LS-based engine that spins to 8,000 rpm and produces 750 horsepower. Chevrolet relies on a supercharger to get the same output for the LT5 engine in the Corvette ZR1. (Ironically, Mercury Marine was tasked with assembling the very first ZR1 engine, also a DOHC V-8, back in the early 1990s.)

"This engine represents the best of everything in a hot rod crate engine," says Phil Gerber, owner of Roadster Shop, the exclusive retailer for the SB4 7.0. "It takes LS-based performance to the next level, with a familiar foundation that is already supported in the street rodding world when it comes to engine mounts, transmissions and the like. It also offers distinctive appearance that's unlike anything else."



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Harley-Davidson FXDR By TTS Performance​

Harley-Davidson isn’t exactly popular for building fast motorcycles as most of its offerings don’t even breach the 100 horsepower mark. However, the company’s solid, simple, and reliable engines allow a lot of performance upgrades, and this often results in some seriously fast HDs. One such motorcycle is TTS Performance’s Harley-Davidson FXDR, which pumps out a massive 286 horsepower and nearly 250 pound-feet of torque, going completely against the grain of Harley's typical power figures.

TTS Performance is a specialist in plonking superchargers into production motorcycles and pushing the boundaries of performance. The FXDR also incorporates a supercharger, the protagonist for this serious power output. The supercharger produces 22 pounds of boost and works in conjunction with a bespoke intercooler and oil cooler to keep the temperature in check.

TTS has also thrown in a self-built CNC-milled 90mm throttle body, which allows maximum performance and makes things all the more impressive. Speaking of impressive, the build quality of all the components is top-notch, and the shop has even mimicked the engine fin style, so everything appears “normal” from the outside. These changes aside, the FXDR remains as is elsewhere. The motorcycle rolls on the OEM suspension (upside-down forks and monoshock), and the chassis remains the same. Similarly, the chain, sprockets, and features are all stock, too. Judging from what TTS’ 200-HP Road King did on a drag strip, we’re pretty sure the FXDR will record low 10-second quarter-mile times. Even a sub-10-second time won’t be a surprise here, but we feel the stock underpinnings won’t allow that.

Sadly, we don’t think this FXDR is up for grabs, and even if it was, shipping the entire motorcycle from across the pond is a hectic affair. The way out, however, is that you order the supercharger and related components from TTS, get them delivered to your doorstep, and then find a trusted local mechanic to put it all together. That way, you can fine-tune things to your liking and enjoy your supercharged Harley to the fullest. For reference, the FXDR is no longer part of Harley-Davidson’s catalog, but you can find a used one easily, or simply get in touch with your local Harley dealership and ask whether they can arrange it for you. If you just want a supercharged motorcycle, regardless of the make or nature, then you can also check out the Kawasaki Ninja H2.

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