Modern Heart: Rocky Auto’s Rb30 Powered Z

Nothing is as it seems in Japan. As a rule of thumb you should never, in any circumstance make any sort of assumptions about any car you see on the street. This is especially true if that particular car proudly wears the Rocky Auto name, a shop we are all pretty familiar with these days. With the Nostalgic Two Days show coming up tomorrow I though we might as well start getting into the vintage swing of things and what better way than a high performance classic from Watanabe-san at Rocky.

“Modernizing” is something a lot of people are attempting to do with their cars, even those that aren’t that particularly old. Heck I’m attempting to do the same to my GT-R, trying to add upgrades and other little bits and pieces that will help bring some aspects of the whole package into the new millennium. Except what you see here sort of takes that whole notion to extremes.

This is the point purists should probably look away. While Watanabe-san does offer authentic restorations, it’s not something his customers are exactly into. The whole idea behind one of these cars is the fact that they manage to combine the looks and feel of a classic car – in this case an S30 Fairlady Z – with a modern, reliable and more powerful engine and driveline.

Built last year, this is one of a few rides that Watanabe-san classifies as his “favorite.” Looks wise he has gone with the “ZG” look…

…painting the car in the period correct dark maroon and adding the long-nose conversion, the fender flares the trunk spoiler and the fender-mounted mirrors.

The car is fitted with special modern-day dampers that Rocky Auto developed for the classic Z and sports a set of 16-inch Watanabes wrapped in Bridgestone Potenza GIII street tires, 205/50 up front and 225/45 at the rear. It’s from this point on that you begin to notice the subtle yet important changes that have been made, like the front 4-pot AP Racing brake calipers and cross-drilled rotors.

But things don’t really get serious until you lift the stock hood…

…revealing the awesomeness that powers this Fairlady. As Watanabe tells us, it’s not all about horsepower numbers; he’s built some very powerful Zs in his time, but he much prefers creating something more balanced, a conversion that builds upon the car’s original character, making it even more evident.

He has found all of this in the RB30-based engine he has created for this, as well as a few other builds. It’s a straight six just like the L24 that powered the S30 in the first place, naturally aspirated and delivering just the right about of power to the rear wheels. It all started with an Australian-sourced RB30 bottom end, onto which he dropped an RB26 twin-cam head. The engine breathes in through six aluminum velocity stacks – part of the “sports injection” system that Rocky Auto devised. If you recall the Rocky carbon bodied Fairlady we featured last year was also powered by an RB30, except it was running on 50 mm Solex carburetors and higher lift & duration cams. Watanabe really liked that car but wanted something a little bit easier to live with, something more street oriented.

As if seeing a gold RB26 head in the engine bay wasn’t enough, Watanabe-san made sure that the visual aspects of this engine swap didn’t end there…

…fabricating a beautiful and complex set of stainless steel headers, the same 46 mm 6-into-1 items that were used on the carbon car…

…helping to really emphasize the unmistakable straight-six sound that exits through the rest of the exhaust system.

The engine is good for just under 300 HP, about double what the S30 came with back in the early seventies. To transfer drive to the rear Cusco 2-way LSD a R32 Nissan Skyline 5-speed transmission was fitted, more than able to deal with the power at hand and the occasional track day abuse.

Out on the roads around the Rocky Auto HQ in Okazaki, the Zed looked phenomenal, the RB30’s scream reverberating across the hills we went to shoot around on. The three liters of capacity and the somewhat mild stock RB26 cams all help deliver a very strong low and mid range, making it a pleasure to drive around on a daily basis. Despite the longer stroke the RB30 is still and RB, so has no problem to rev to higher than normal rpm. For durability however the redline has been set at 7,000 rpm.

The restoration-slash-modernization of this S30 continues inside where, along with a dose of spot welding around the door openings, glasshouse, front and rear suspension turrets, engine bay and other strategic locations – a bolt-in roll cage was added.

This spans to the rear of the car and down behind the seats, helping increase torsional rigidity of a frame which is well over 40-years old now.

There’s no doubting that Nissan really got the interior design right all those years ago, standing up to the test of time rather well. Still, to make things nice and comfortable Watanabe spent some time adding a few nice touches like the R32 Skyline automatic climate control system, modern HD navigation with pop-out LCD screen…

…and a pair of Recaro leather/alcantara seats – with Willans harnesses for the driver.

The mix of old and new continues with a classic Datsun steering wheel…

…original main gauges….

…and the addition of a triplet of modern clocks from Blitz.

The period correct wooden shift knob and well used leather boot serve as a constant reminder of the car’s vintage-ness.

It might be a different school of thought to those that restore older cars in a more period-correct way, but for some reason the Japanese manage to pull it off so well especially when applied to cars like the Fairlady Z. Even if you may be a purist, it’s hard not to admire and appreciate the work that went into creating something so special. If that’s not the case maybe a quick ride in this RB30-powered Rocky Auto creation may change your mind…


Engine: RB30/RB26 hybrid engine swap, Rocky Auto engine mounts, Rocky Auto sports injection with aluminum velocity stacks, Tomei Powered fuel rail, RB26 injectors, Rocky Auto 46 mm 6-into-1 exhaust header, Rocky Auto stainless steel exhaust system, Billiion power steering reservoir tank, Rocky Auto gold head covers, clear cam covers, Koyo radiator, HKS oil cooler, R32 Skyline fuse box & wiring loom, Power FC ECU

Transmission: R32 5-speed transmission, Exedy single plate clutch, Cusco 2-way LSD

Suspension & Brakes: Rocky Auto front coilovers, Rock Auto rear dampers, Cusco carbon front strut tower bar, AP Racing 4-pot front calipers, cross drilled rotors

Wheels & Tires: Watanabe wheels 8Jx16″ front 9Jx16″ rear, Bridgestone Potenza GIII 205/50R16 front, 225/45/R16 rear

Exterior: ZG nose, ZG front & rear overfendes, ZG rear spoiler, ZR side mirrors

Interior: Spot welded and reinforced shell, bolt-in roll cage, Recaro driver & passenger seats, Willans drivers-side harness, Datsun spot steering wheel, R32 Skyline A/C unit, Carrozzeria HD navigation system, Blitz dials (ex. temp, oil temp., water temp.

Rocky Auto 

Rocky Auto Features on Speedhunters

-Dino Dalle Carbonare



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Every S30Z feature I read makes me regret selling my '73 last year... Oh well, hopefully someday soon I will find another.


Beautiful, nothing like the classic Z's shape.


Is that not the same engine that was in the Ken Mari??  Though it would not be hard for them to build another lol.  I really like the headers on this car.


Beautiful car!!!


Those aren't air vents, their the original spots for the gauges, and thats a datsun competition steering wheel, kinda hard to find, cool feature nonetheless!


this is perfect. i like a stock classic as much as anyone else (more probably) but i wouldn't kick a G-nose out of the garage for having  modern internals
in fact one of my dreams is to build a first gen alfa duetto spider (not start with a real one) on the chassis of an NA roadster. or i guess since i am adding new body it could be NB or NC since i like NA best for looks, which are irrelevant here. but anyway the result is a very pretty car which is actually reliable, and unlike beetle or fiero kit-car rebodies, is actually good because i started with a mazda roadster. also i had this dream before they announced that mazda and alfa were "working together"
like i said, i love and appreciate classics as much as anyone, but for when i want to get to work and my real alfa is broken, why should my backup car be an ugly modern one?


Almost perfect, but it's 101% done. Remove (or hide) that alpine head unit and it would be complete.


This is the dog bollox of Z's it


Gorgeous. Absolutely gorgeous.


such a terrific all around build with amazing attention to detail


hey guys.. if any one can help me out... why did he choose the rb26 head over the rb30. i notice alot of the honda guys do swaps like that switching the heads.


wow that is amazing


whats the purpose? bigger valves ? more flow? i don't see the purpose


this is how a restomod should be done. very nice .




@zackspeed333 no, it isn't. the RB30 was a 3.0l engine that was used in some skylines and holdens in the 1980s. kenmeris had either a G16, G16, L20A, or S20 (S20 being the engine in the GT-R, both C10 and C110 (and Z 32), and probably the one you're thinking of)


all RB30 are single cam, probably used a 26 head to have twin-cam instead (my guess since the article explicitly mentions the twin-cam when he says which head it's using)


@zackspeed333 that's Z432, not Z 32.




honda guys dont just switch heads for the hell of it. they swap out VTEC heads for their non-VTEC heads. 
and the only time anyone should ever swap out a head is for better airflow and better overall performance goals.


they swap in*


The three pods where the Blitz gauges were put were originally gauge pods, not air vents.


I really like how Rocky Auto mods their cars. Resto-mods done right.


THIS is MORE like it! Much better than their faux carbon fiber wrapped S30...that was ghastly.


any chance we can get a video up for this? i would love to hear how it sounds


A 240ZG with more power...most excellent.


@ToneDiez Are you sure it was a wrap??? I thought it was real dry carbon panels.


@ComJive Yea I am aware of the RB30 but one of there Kenmarie cars has this same engine setup that was in the video posted the other day.


Favoritest. Z. Ever. #2 would be...any of the Z's Paul Newman raced. I got to see the twin turbo V8 at Watkins Glen and his other cars as primary features of the Vintage Gran Prix, so angry and deafening. Anyway a close #3 would probably be Tara's of iheartstance fame...


@zackspeed333 Nope. It was definitely a wrap, that was really the only thing people knocked on the car when it was posted on SH awhile back.


Ladies and gentlemen, the RB30 in its natural habitat.


Lovely.  I think the RB swap is perfect for the 70's nissans and datsuns.  I'm surprised they're not more common than they are.


How do these Japanese guys run open ITBs?  I did it on a 4age and fried the rings within 20,000 kms.  Awesome build, love the header especially.


@ComJive Also rb26 head came stock with an ITB setup, maybe that has something to do with it too


I would give up a couple body parts for this car.


@ToneDiez  @zackspeed333 
The removable panels were real carbon and the rest of the body was wrapped to match


@Paizuri_4g63 does the twin turbo v8 still exist? Would love to shoot this car!


question a friend of mines had a fx16 corolla with a red top 4 age and he had to replace the motor every 15 thousand miies. why is that if you know.


Perfect, I would change nothing.


Dino, what are you trying to do to me bro, I hate my Z now :-D


Moar pictures!!! This car is stunning


@zackspeed333 They posted a video of a hakosuka with some kind of V8 (i think a 1UZ but I don't know V8s), is that what you're thinking of?


@Larry Chen Glad to know I'm not the only one feeling that way about my Z right now... ^_^


What a well executed build.  That color looks beautiful.


@E Sutton  @Larry Chen I comment this on every Z post. Why is my Z so new D:< lol


fine combination of both classic and modern, that header is a beauty.


such a beauty! perfect mix of the old and new :)


@RodChong  @Paizuri_4g63 YEAH man, They raced all of them at the glen and lined them up in victory lane, a 240, 280, the 300zx twin turbo which was just a fucking monster with vents, wings and louvers all over the place and a couple 510's he raced. Him an his Z's were a big part of the Glen. They honor a different marque every year for the vintage gran prix with a ton of cars that show up. That year was nissan...THIS year...I know what this years is but I'm not allowed to say but it will be epic. They are keeping it very hush until September. I will say its pertinent to what SH has covered...recently. Either way if I were you or any auto photographer I would book a hotel and tickets NOW. This will be the shoot of  a lifetime.


@RodChong I can find out who owns that 300ZX as the gentleman I work with (regional SCCA) is a part of the racing museum and a rain man of race cars and their owners. In the meantime look for my profile name (Paizuri4g63) or GTuned's photos on Jalopnik/Opposite Lock to see what caibre of cars  can show up there. If you're a car person The Glen is a mandatory pilgrimage. Come and I will do my best to receive any one of you.


@Paizuri_4g63  @RodChong Guh forgive me it was the 1981 IMSA 280ZX twin turbo V8 why cant I delete these things...


@RodChong Forgive me it was the 1981 IMSA GT 280ZX twin turbo V8


@RodChong Forgive me it was the Electromotive/Bob Sharp 1981 IMSA GT 280ZX twin turbo V8 @ 800hp


@zackspeed333  @ComJive Yes they have also fitted the same engine into the Kenmeri that was in Retro Car Kings


@zackspeed333  @ComJive Yes they have also fitted the same engine into the Kenmeri that was in Retro Car Kings


@ToneDiez  @zackspeed333 Yes some parts were wrapped


@ToneDiez  @zackspeed333 Yes some parts were wrapped


@tnle Luke & Maiham Media should have a video of this coming eventually


@tnle Luke & Maiham Media should have a video of this coming eventually


@Larry Chen LOL your car is awesome at it is, bet it has better turn in ;)


@Larry Chen LOL your car is awesome at it is, bet it has better turn in ;)


Companies in the UK do very similar "modernising" to cars such as the E-Type and DB6, I think it's a really nice idea as it means these cars will continue to be used as they were originally intended all those years a go..... Not cheap though!


is there any video of this?


The only smart thing Holden ever did was put a Nissan engine in a shitbox


Hi , i went ask about a gold rb 26 head in the engine from where can i purchase ? Please tell me soon .