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Vorshlag - 1966 Honda S600 Coupe + Motorcycle engine?

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  • Vorshlag - 1966 Honda S600 Coupe + Motorcycle engine?

    Project Introduction - October 28, 2025: Well right after making big headway with our Honda J37 swap into a Toyobaru 86, now I'm back making more poor decisions!



    Look, I have lusted for a tiny Honda car like this since I first rode in one in college. My buddy back then had two Honda N600 (FWD 2-cylinder air cooled tiny car) and an S800 Coupe (RWD with high revving 800 cc motorcycle engine), and the S800 was an autocrossers DREAM! High revving engine, super lightweight and SMOL

    THE BASIC HISTORY OF HONDA'S FIRST SPORTS CAR

    The Honda S360/S500/S600/S800 roadsters and coupes were the first production cars the Honda Motorcycle Company released, and they were very sporty cars right out of the gate (the S360 was first but it never made it into production).



    The Youtube video linked above by Jason Cammisa perfectly explains the lore behind these first Honda sports cars. I've known about these cars for 35 years but still learned a lot from this video - fun!



    Ideally the image above is what our 1966 S600 Coupe should look like - the one we bought was originally red, and had this exact shape and size. That's the image what I remember from so many years ago, riding and driving one of these in the early 1990s. And yes, even at 6'3" of height, I easily fit inside the micro car.



    I first stumbled upon this car a decade ago sitting under a tarp at a Texas race track called MSR Houston, and found out it was owned by a legend in motorsports circles there, James Rogerson. I have been trying to buy this car ever since, and it is a bit worse for wear after a decade of Houston coastal humidity and a few hurricanes.



    This image above left shows this actual car as modified by some crazy autocrossers back in the 1990s running in SCCA Solo EMOD. They had swapped in a spicy 12A rotary engine, added flares, and all sorts of major mods - the hood has both the reverse cowl scoop and a hole for the carb. The image above right is a nearly stock S800 being autocrossed.



    Back in 2006 James and his brother cut off the old flares, ditched the ancient suspension, and built a new (albeit temporary) frame to hold front and rear NA Miata subframes and suspension. The above left pic was them dropping the body onto the setup to make it rolled, and above right is mocked up at the proposed ride height. The areas they stripped of the flares and the roof were stripped of paint.



    And in October of 2025, nearly 2 decades later, it looks like this above. The ride height is all jacked up because this is still the temporary frame setup that was never bolted fully to the body. And the areas devoid of paint have a wee bit of rust after nearly 19 years of coatal Houston humid air and multiple hurricanes. I sent these pictures to my sandblasting guy, who said NOT to blast this thin, 60 year old Japanese sheet metal.



    My engineer Jason here at Vorshlag took these 2006 pictures and raced with James over the years, and every time I'd see him call on caller ID, I'd tell Jason to remind him I wanted to buy that S600. I should have pushed harder, but I've had a lot of projects going on since then. A few weeks ago James finally said "yes" and I moved my schedule around to go get this wee car before he changed his mind.



    I picked up this car last Sunday in my trailer (a 12 hour round trip tow, and we never left Texas) with two of my endurance racing college buddies. James sold it to me for not much money - what I got from my last bi-monthly recycling runs here (our CNC room makes a lot of chips and scrap) - but I regret not hounding James more often over the last decade, because it looked pretty good when I last saw it in 2016.



    Yesterday after our Monday morning weekly meeting most of the Vorshlag crew looked at this car inside the trailer, and they were a little harsh. It looks pretty rough, but I know what it CAN look like, and how much potential is in this wee little chassis.



    Within 45 minutes we had all of the glass removed (its all there and intact, except the door glass!), the rotten rubber seals out, and all of the wiring removed. Then the gauges, dash, and spare parts inside were all removed. It was ready to blast, but now it is going to be cleaned up with a "LASER".

    RESTORATION PARTS HUNT

    James had most of the chrome trim and even a grill and spare nose (from an S800), but of course from what you can see, we might need a few things.



    If anyone reading this has a source for parts for this rare chassis, please let me know! This car is too far gone to be "restored" but I would like to make this a fun, streetable autocross car with the right trim pieces, brake lights and such.



    As you can see from this resto-modded S600 roadster, the headlights and other bright work are very unique. This Speedhunters article shows more on this motorcycle powered blue S600.



    With the fenders already mauled I doubt we can make our Coupe look as good as this blue roadster, but I'd really like to get the correct lights and mirrors at the very least.

    DRIVETRAIN SWAP - OF COURSE!

    This car has zero drivetrain, other than what's left of an NA Miata's rear diff. The tunnel is pretty jacked up but we can restore that metal, as we have fabricators with skills here.



    The engine bay is SMOL but we have seen Honda K24 swaps done on these, yet they always stick out of the hood.



    A Motorcycle engine swap is wildly appropriate on this car because it CAME with a motorcycle based engine from the factory, and that fits well. I am not a "motorcycle guy" and have limited knowledge on what to use, so any input from readers here will be looked at closely. Between the MotoIQ article above and the Miatabusa project, we're learning what we can.



    The blue roadster above has a 1200cc DOHC inline four from a 2006 Kawasaki Ninja ZX-12R, and I show this for reference - an inline four cylinder 1000-1200cc sport bike engine is a good fit.



    Using a motorcycle engine is pretty exciting, and I've always wanted to swap a very light car with a super bike engine. And while I am open to off-brand engines, I'd really like to keep this an all Honda swap for power. The CBR1000RR is a very spicy 1 liter bike engine, making 172-193 hp, depending on the year. We would like to use something fairly modern so it is fuel injected, if possible. These seem to sell for $2800-3500 and don't always have everything we need.

    We understand the challenges and limitations of using a motorcycle's cassette style sequential 6 speed gearbox and driving a RWD car's rear axle. Engineer Myles here ran Formula SAE at UTA, a top level team, and both built and drove their winning formula car with this sort of drivetrain. He has experience with the shifter, clutch, etc. Jason ran a motorcycle powered Lotus 7 with a similar setup, and several others in our crew are motorcycle nuts. We can make it work, taking the output sprocket and machining an adapter for a driveshaft, but it won't ever have reverse.



    We started looking at shaft drive motorcycle engines, and Jason found a BMW 900cc and Myles found the 6 cylinder Gullwings (which do have reverse but the engines are pretty lackluster and LARGE). Then a Facebook follower pointed out the Honda VFR1200 which had a shaft drive and an optional 6 speed DCT transmission. These could work both as manually shifted dual clutch sequentials or in an automatic mode.

    And I love DCTs with a passion. I am selling my soul to get a C8 Corvette to do suspension development with, and half the reasons is that Tremec 8 speed DCT transaxle, yowsa it is good!



    Anyone ever ridden one of these VFR1200 DCT Hondas? I've watched videos but have never seen one. Can we make it work in a 1200 pound car? I mean, we can swap over speed sensors, shifter buttons (to paddles), and even the ECM and gauges from a bike (sounds like I'd need to find a complete bike, maybe one that has been laid down). Engine is rated at 173 hp at 10,000 rpm, about what the earlier CBR1000RR engines make. And it is shaft driven. And DCT!

    SUSPENSION IDEAS

    The Speedhunters blue roadster uses narrowed Miata subframes, suspension, and rear diff. Which we could easily replicate here, along with a much needed new floor and some lightweight cage structure.



    Everyone here at the shop knows Miatas so swapping over those bits makes the most sense, but the track width is a challenge. Imagine a fully loaded S800 coupe at 1300 pounds instead of 2350 (without driver), that would be wild.



    Again, it is currently rolling around on two Miata subframes and an axle, but it needs a lot of work and an all new frame to make it sit at the correct ride height, steer, etc.

    WHAT'S NEXT?

    Getting the body panels "LASER" cleaned is a big step, and I won't invest too much more effort into this build until we see how much of the rusty stuff cleans up.



    Remember - I've wanted one of these for 35 years, and might have made a poor decision. We will post more after the metal is better evaluated.

    Thanks for reading!

    Terry @ Vorshlag
    Terry Fair - www.vorshlag.com
    2018 GT / S550 Dev + 2013 FR-S / 86 Dev + 2011 GT / S197 Dev + C4 Corvette Dev
    EVO X Dev + 2007 Z06 / C6 Dev + BMW E46 Dev + C5 Corvette Dev
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