NISMO’s 40th Anniversary Celebrated With a Drooly L-Series DOHC Cylinder Head

Way back in 1984, when your dad was wearing denim from head-to-toe and your mom was rocking a perm and cozy leg warmers, Nissan was busy combining its two dependable motorsport divisions and NISMO, or Nissan Motorsports International, was born.

Engine swapping is common among classic Z builders, but those that stick with the car’s native L-series engine dream about the possibility of giving it dual overhead cam performance and separating its intake and exhaust which sit far too close to one another. Over the last few years NISMO has been tinkering with a completely new DOHC cylinder head that they call the “TLX,” which fits atop L-type engines found in the iconic 240 and 260Z, as well as the 280ZX chassis.

In the demo vehicle and display case they presented at Nostalgic 2 Days 2024, a car show held in Japan that’s dedicated to classic cars and parts, the specs listed showed a bore and stroke of 89.0mm x 79.0mm, displacement at 2,949cc, a compression ratio of 12.5:1, and a 7,500 RPM redline on the way to almost 300 naturally aspirated horsepower—more than double the factory engine’s output. A coil-on-plug conversion, EFI/ITB set up, and a custom header certainly play a part in that claim. Unfortunately, at this point there are no plans in the works to make head available to the public.

One of the other interesting parts of this unveil is the old school NISMO logo cast into the valve cover, which, interestingly, uses over two dozen bolts to attach to the head. The logo seems to be making a comeback beyond just the rocker cover, with tags attached to various interior parts and signage seen in and around the display.

If the DOHC conversion sounds somewhat familiar to those that don’t dabble in the old school Z-car arts, it has been done before. OS Giken’s TC24-B1Z, which features a unique multi-cog gear drive as opposed to a traditional timing chain was established by its founder, Mr. Okazaki in the 1970s.

His forward-thinking head design reemerged as an updated version about a decade ago when OS, who had displayed the L-series DOHC creations at SEMA on multiple occasions, began selling them. And, no, they aren’t in any way cheap. Top quality components and godly-levels of development come at a price, and that price is in the neighborhood of $40,000. A more cost-effective route to DOHC enlightenment can be found through the genius of Datsunworks’ home-developed KN20 head, which is based on Honda’s K-series cylinder head architecture and uses a number of Honda’s off-the-shelf components. That set up starts at a base price of around $10,000 with additional parts and some machining required to make it all work.

Based on those two examples and the fact that this version was produced in-house by an OEM, we can assume that the price would likely sit north of $40,000, should the dream concept ever come to fruition.