The Evolution of NISMO and the New DOHC Cylinder Head for Classic Z-Series Engines
Way back in 1984, Nissan was busy combining its two dependable motorsport divisions, which led to the birth of NISMO, or Nissan Motorsports International.
Innovative Developments in the Classic L-Series Engine
Engine swapping is common among classic Z builders. However, those who maintain the car’s native L-series engine aspire to enhance its performance with dual overhead cam (DOHC) capabilities. This enables the separation of intake and exhaust systems, which typically sit too close to one another.
NISMO has been developing an innovative DOHC cylinder head known as the “TLX.” This cylinder head is compatible with L-type engines found in the iconic 240Z, 260Z, and 280ZX chassis. The demo vehicle presented at Nostalgic 2 Days 2024 featured impressive specifications:
- Bore and Stroke: 89.0 mm x 79.0 mm
- Displacement: 2,949 cc
- Compression Ratio: 12.5:1
- Redline: 7,500 RPM
- Power Output: Nearly 300 naturally aspirated horsepower
This output is significantly more than double that of the factory engine. Furthermore, improvements such as a coil-on-plug conversion, EFI/ITB setup, and a custom header contribute to this enhanced performance. Unfortunately, at this stage, there are no plans to make this head available to the public.
Classic Design Elements
The reveal of the new cylinder head included the classic NISMO logo cast into the valve cover. Interestingly, this valve cover secures with over two dozen bolts. The logo’s revival extends beyond just the rocker cover, showcasing tags on various interior components and signage affiliated with the display.
Historical Context and Competitor Development
The concept of a DOHC engine conversion may sound familiar to enthusiasts. For instance, OS Giken’s TC24-B1Z features a unique multi-cog gear drive rather than a traditional timing chain and was pioneered by its founder, Mr. Okazaki, in the 1970s.
This innovative design reemerged in updated forms about a decade ago when OS, who has showcased their L-series DOHC creations at various automotive events, began selling them. However, quality components and extensive development come at a premium; such setups can cost around $40,000.
An alternative to achieve DOHC capabilities is found in Datsunworks’ home-developed KN20 head, which leverages Honda’s K-series architecture and off-the-shelf components. This cost-effective option starts at approximately $10,000, with additional parts and machining necessary to complete the installation.
Considering these examples, and with the TLX design produced in-house by an OEM, it stands to reason that should this head come to fruition, its price would likely exceed $40,000.
