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 Friday 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 15 hours ago15 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 14 hours ago14 hr by Zed Head

Twin cam cross flow does sound fun though!

9 hours ago, SteveJ said:

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.

I attended a presentation on the new kit at NISMO's Omori HQ last week, and the bellhousing/transmission question was brought up. NISMO's staff said that the FJ20 engine's bellhousing can be used (it's pretty much the same as the one used on the LY crossflow) allowing the 71-B family transmissions to be used, but they expect the aftermarket to step up and adapt 71-C family and NISMO 6-speed transmissions in the way that, for example, ESCORT have done for the L6 family.

One thing that strikes me is that people are talking as though individuals will be able to purchase these kits/parts for their own home builds. That's not how NISMO told us they intend to release them. They are going to appoint known, recommended and trusted engine building companies as authorised buyers and they will be given technical assistance with the builds. It will be up to these authorised builders to deal with customers who want to purchase finished engines/drivetrains/complete packages. NISMO won't be selling these parts direct to civilians...

Edited 5 hours ago5 hr by HS30-H

8 hours ago, Zed Head said:

Seems like poor timing on Nissan's part, waiting so long to introduce their head, when there were already two out there.

This is a NISMO project, intended as part of an anniversary of their founding year. THAT is the timing context.

I very much doubt that NISMO (it's not a NISSAN product) paid too much attention to what's "already out there". Most of the people carping and whining about the NISMO kit didn't buy an OSG or Datsunworks head either.

    

So close. I almost went for it. You even left an ellipsis to draw people in. Well done, again.

You are a master at baiting people...

p.s. proper grammar would use the word "directly", I believe, not direct.

37 minutes ago, HS30-H said:

NISMO won't be selling these parts direct to civilians...

Edited 4 hours ago4 hr by Zed Head

1 hour ago, Zed Head said:

So close. I almost went for it. You even left an ellipsis to draw people in. Well done, again.

You are a master at baiting people...

p.s. proper grammar would use the word "directly", I believe, not direct.

I have no idea what "bait" you are imagining you see. I made a couple of - I judge, having sat in front of the very people who came up with the parts in question, listened to their reasoning and their answers to sensible questions - informed comments on the topic. Contrast this with your finger-in-the-air type ruminations (yes, maybe they have indeed "considered" the transmission issue...) and you're talking about "bait"?

Thanks for the grammar lesson (LOL, is that all you've got?). I'm English - more specifically a Londoner - and that's how we tend to say it over here. You might as well be advising Miles Davis to stick to the melody. But if you're suddenly volunteering to be this site's speeling and grammer policeman then by all means go for it. Citizens will demand fair and equal treatment of all cases. Good luck with that.