I’m at the point in my life where Harbor Freight Predators are more intriguing than LS engines. Obviously, they can’t hold a candle to GM’s budget performance darling, but you don’t see them swapped into every classic truck and hot rod (only the random Honda Insight or Chinese UTV). Then, you have folks like Red Beard’s Garage on YouTube who built a 670cc Predator, complete with a turbo, billet pistons and connecting rods, electronic fuel injection, and more. How could you not be hooked?
This fella does all kinds of work on small engines. You can watch him tool around with single-seater go-karts, like the Yerfdog Spiderbox—what a name—as well as modded pit bikes. But this V-twin build might be the most extreme project he’s taken on, in terms of real speed upgrades.
Quite a few aftermarket companies provide support for the 670cc Predator, so Red Beard’s Garage had plenty of parts to choose from. In addition to the turbo he bought off Amazon, which normally helps power Bobcat skid steers and Doosan forklifts, he’s running a big-name Holley Sniper EFI, plus billet rods and pistons, a billet flywheel, roller rocker arms, electronic ignition, and an upgraded 507 camshaft from Performance Machine and Design. The head work was taken care of by Beckwith Performance, a friend of the shop that specializes in Predators, as well as Briggs and Stratton and Kohler motors.
Seeing as you can buy a stock 22-horsepower Predator 670 for $949, the costs of these parts can easily double that. Fortunately for Red Beard, he got many of these upgraded components for less, as they were used. Maybe you’ll get lucky and find similar deals, but just keep in mind—this isn’t as low-budget as jetting the carb on your minibike.
What any DIY fixer will appreciate is that the host details every part of the job, sped up slightly with on-screen captions that explain what tools he’s using for the job. There’s also chill voice narration that’s easy to track. Combined with steady camera work, it’s a joy to watch.
Red Beard plans to run 12 psi of boost through this engine, which ought to be plenty to wake it up. It isn’t exactly clear just yet how much power it will make. He already has a supercharged Predator-powered go-kart that makes 14 psi, and it’s pretty rowdy. He’ll run the two against each other once the turbo build is finished to see which wins.
No matter what, boosted Harbor Freight engines are something I can get behind.
Stage 5 670cc Turbo EFI Engine Build
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