Gearhead News

August 3, 2021
Nissan 240Z Roars With Honda K20-Style DOHC Head

The Nissan 240Z is an automotive legend, pairing a design for the ages with fun handling and a snarling inline 6. Of course, in this day and age, that motor is a little down on power compared to modern sports cars. Engine swaps are popular with the platform, but some feel that doing so takes away a little too much from the car’s original feel. Enthusiasts now have another option, however—a Honda K20-style DOHC head for the original Nissan L-series engine, built as a collaboration between Datsunworks and Z Car Garage.

As seen on Youtube, the engine makes a glorious wail, soaring through the rev range with a ripping, tearing sound that seriously means business. The example shown has been given the works, fitted with individual throttle bodies, electronic fuel injection and paired with a six-speed swap to best put down the power. How much power, you ask? In an early state of tune, the combination of the Datsunworks KN20 head with a Rebello 3.2L L-series block produced 350 horsepower and 248 lb-ft of torque at the wheels, running on 91 octane. 

YouTube/alvingogi

The engine runs impressively smoothly, and is tuned for street drivability over all-out power. The exhaust note is a compelling one. The naturally-aspirated roar with double overhead cams brings to mind other cutting-edge 80s and 90s performance engines. Close your eyes and you can practically hear how easily the motor breathes, gulping down buckets of oxygen as it tears down the road.

YouTube/alvingogi

The story of the KN20 head goes back to 2014, with Datsunworks founder Derek Minetti developing the concept over the years and posting about it on the HybridZ forums along the way. The design came about after discussion around what it would take to produce a double-overhead cam head for the L-series engine. After looking at Nissan’s own RB and KA motors, the Honda K20 ended up serving as a model for the design. It’s no surprise, given the performance capability of the K-series motor. We’ve even seen one end up in a Prius.

Coming stock with features like roller rockers and removable cam towers, along with great aftermarket parts availability, it made perfect sense to adapt the K20 head design to the L-series block. After measuring a K20 and finding the basic concept to be compatible, Derek set about creating the KN20 head from scratch. Seven years later, we get to enjoy the music of that sonorous exhaust.  Thus far, 10 heads have been made, with 3 installed in running cars. Down the track, Z Car Garage hopes to offer the head as a bolt-in setup for L-series engines.

A powerful naturally-aspirated straight six is a great way to maintain the character of the original Z cars. A head swap is far more approachable than doing an entire engine swap, too. While the custom castings and build surely don’t come cheap, neither do vintage Nissan sportscars. We only hope that one day, we’ll see—and hear—one in person.

Got a tip? Let the author know: lewin@thedrive.com