SEMA: OSgiken 24 Valve L28 240Z
[dropcap style=”style1″]E[/dropcap]ngines are simply nothing short of amazing. The mechanical symphony of an old school straight six engine rivals the Seven Wonders of the World. The way valves glide in harmony, timing chains mesh gears, and the crankshaft rotates like a clock’s pendulum to sing ever so sweetly like a canary on a bright summer’s morning. When a manufacturer builds an engine, the results can range between catastrophic and awesome. When a manufacture builds and supports an engine created in an era when the original Star Wars was a big hit, well the result is nothing but love. Sweet, unaltered, bliss. These words describe the TC24-B1Z developed by OSgiken.
Developed on the L28 architecture for Nissan Z cars, the TC24-BZ1 began development back in 1980 as the TC24-B1. The distinct feature of this engine is the 24V twin cam head developed specifically for the L28. This unique head not only features more valves per cylinder from the original 12V single cam head, but lighter rotating assembly. The bottom end of the engine has been reinforced as well with a special reinforcement plate/girdle system. This helps eliminate harmful vibration to stabilize the engine for revs past the 8,000rpm threshold. The result was an engine of fierce nature producing 320.5 NA hp from 2.8 liters at a compression ratio of a tight 11.0:1. While peak power was recorded at 7,400 rpm, this engine was capable of revs up to a magical 10,000 rpm.
The TC24-BZ1 is 35 years of development and improvement over the TC24-BZ1. Cranking the figurative dial to eleven, the TC24-BZ1 design refines the TC24-B1 akin to a finely aged wine to perfection. Eliminating the chain driven timing system of the original engine, the TC24-BZ1 utilizes a gear driven timing system. Camshaft towers transitioned from a solid single piece to a two piece cap to further reduce friction and ease serviceability. Rocker arms have also been changed to shim buckets for lightness as well as improved oil lubrication with special channels. Improvements over the old engine are nothing short of phenomenal. Rotating assembly on the bottom end grows to 3.2 liters with increased bore and stroke. Peak power increases by 96 to an S65 rivalling 414 hp at 9,000 rpm. Redline remains the same godly 10,000 rpm.
While the respect for support on older engines may appeal to a smaller crowd, the TC24-B1Z unveiled at SEMA is one of the most amazing things to debut at the show. OSgiken delivered yet again with a high quality offering to match the top shelf parts many builders lust after. They command high respect in the automotive industry, and high respect for the Z community.