While this is newsworthy, it may not be available outside of Japan... or if it is, will have tariffs added to its already high $25000 dollar price (plus you need more parts to make it work).

https://www.theautopian.com/nismos-old-school-hot-rodding-kit-for-its-straight-six-costs-more-than-some-whole-nissans/

https://www.nismo.co.jp/products/web_catalogue/engine_parts/dohc_conversion_kit_l-series_inline-six_engine.html

https://www.youtube.com/watch?v=7Es-4hnZH5Q&t
https://www.youtube.com/watch?v=CFKIAe952dc

Edited yesterday at 03:39 PM1 day by inline6

@Derek makes something similar.

https://forums.hybridz.org/topic/119641-twin-cam-head-for-the-l6-from-derek-at-datsunworks/?do=findComment&comment=1249401

I watched that progress over the years as he was developing it. It has been awhile since I looked at the details of it, so I am less familiar than I was at one time. I wonder what Derek's options costs (roughly)? I am sure there are various options depending on how the owner wants to proceed. But, I am sure there are some "round figures" for the head, cams, and associated cam operation hardware. Didn't see - does the head accept some off the shelf intake manifold... and header?

Edit - found this https://datsunworks.com/Blog/pricing-for-the-kn20-dohc-head/

Edited 3 hours ago3 hr by inline6

The main challenge in the DOHC is that Nissan opted NOT to develop a transmission mount to deal with rotating the angle of the engine. Stock, it is rotated 12 degrees to the right. With the DOHC, it is rotated 12 degrees to the left. I guess if you're willing to plunk down $25K for the kit, you won't mind spending a few thousand more (I'm thinking around $10K or more unless you do fabrication) for the fuel injection and transmission mount.

Hagerty Media

Nissan DOHC Conversion Kit Can Make Your Classic Z Faster...

The new Nissan DOHC conversion kit lets enthusiasts add dual overhead cams to several classics, like the 240Z.

That's 24 degrees of rotation of the transmission, putting the shifter in the driver's lap. Can't remember which way the VG30 engine is rotated. It uses a different transmission. I wonder if it's a better option. Maybe it's been considered.

Derek is mentioned in one of the articles. I assume that his engine is not rotated? Seems like poor timing on Nissan's part, waiting so long to introduce their head, when there were already two out there. Besides the fact that block supply is diminishing. Slim market.

OS Giken Releases L Series Head - The Gentleman Racer

OS Giken was born in the early 1960s; Osamu Okazaki wanted to build a true high-performance Japanese race car to compete against the sports cars from Europe dominating the sport at the time. Like many

Edited 2 hours ago2 hr by Zed Head