Ultimate Harbor Freight Go-Kart Engine Cost $8,725 to Build—For Real

A Predator 670 engine costs $950 on its own, and the builder didn't stop there as he added Holley Sniper EFI, a turbo, billet internals, and way more.
Harbor Freight Predator engine with major modifications
Red Beard's Garage via YouTube

Harbor Freight is the default choice for budget DIYers across the United States. That doesn’t mean projects involving Harbor Freight products can’t get pricey, of course. I’m not just talking about bathroom remodels, as this insane Predator 670 build from Red Beard’s Garage proves. He started with a $950 V-twin engine and went on to dump more money into it than some people spend on their LS V8 builds.

To be clear, this is far from run-of-the-mill. It has to be the most extreme Harbor Freight engine project I’ve seen, which is why I wrote about it last week. The feller behind Red Beard’s Garage installed parts on this thing that I’d never imagine buying for a go-kart. The full list includes…

  • Holley Sniper EFI system ($1,400 including proprietary USB cable)
  • Upgraded camshaft ($530)
  • Garrett GT1241 knockoff turbo ($400) and oiling accessories ($140)
  • Billet pistons ($460) and connecting rods ($290)
  • Alternator kit ($400)
  • Billet flywheel ($380)
  • Electronic ignition ($340)
  • Head work, like porting, milling, and O-rings ($300)
  • Billet valve covers and rockers ($270)
  • Fuel cell ($200)
  • AN lines ($200)
  • Intercooler core ($160)
  • Exhaust manifold ($140)
  • Intake adapter ($130)
  • Springs and retainers ($125)
  • Intercooler pipe kit ($110)
  • Intercooling pipe couplers ($80) plus odds and ends ($40)
  • Boost reference fuel regulator ($75)
  • Fuel pump ($70)
  • Chromoly pushrods ($65)

Including the price of the Predator 670, that adds up to $7,225. What!? And it gets even more expensive once you throw in taxes and shipping, with that total reaching $8,725.

Harbor Freight Predator
Red Beard’s Garage

The host already has a supercharged Predator-powered go-kart in his garage. He plans to compare this build’s performance to the other boosted one after it’s installed. Per his last video, he’ll be running lower boost levels on the turbo engine—12 psi compared to 14 psi on the supercharged example. Power numbers are still anyone’s guess as he hasn’t strapped it to a dyno just yet.

How Much Did The Turbo 670cc Cost?!?! thumbnail
How Much Did The Turbo 670cc Cost?!?!

He acknowledges at the end of this video that he could have built a more powerful ATV engine for less money. Heck, he could have bought an entire vehicle with more power for that amount. But he wanted to see what was possible with the Predator platform, which is easy to mount, cheap to maintain, and easily serviceable.

I’m glad someone was willing to do it, because I’m sure as heck not gonna.

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Caleb Jacobs

Senior Editor

From running point on new car launch coverage to editing long-form features and reviews, Caleb does some of everything at The Drive. And he really, really loves trucks.