By the end of the 1960s, automotive engineers realized it was necessary to control cylinder head temperatures to moderate emissions of NOx. And the EPA was mandating ever-tighter rules and regulations for air pollution. The air-cooled engine had to go.
But there were a few manufacturers who had built their reputations on air-cooled engines, and they continued to believe in them. Among them were Honda of Japan and Citroen of France. Within months of each other, in 1969 and 1970, they introduced brand-new cars with air-cooled engines designed from a clean sheet of paper. The cars they powered were small by American standards, but mid-size in their native countries. We’re talking about the Honda 1300 and Citroen GS.
Honda 1300.
Honda had been dabbling in microcars as a sideline to its fantastically-successful motorcycle business for a few years. But these were just a curiosity outside of Japan. Soichiro Honda, the founder and master of the Honda company, wanted to enter the big leagues. He wanted to manufacture a car that could be sold outside the home market in large numbers. Something that would compete with the Toyota Corona and Datsun Bluebird.
With the exception of a few water-cooled Formula 1 cars, Honda built nothing but air-cooled engines for its motorcycles and cars through the 1960s. Soichiro Honda loved air cooled engines. “Since water-cooled engines eventually use air to cool the water, we can implement air cooling from the very beginning,” professed Mr. Honda. And he wasn’t taking no for an answer, for he personally oversaw the engineering of the new 1300 automobile.
Offered as both a sedan and a sporty coupe, the new Honda 1300 bristled with innovations. It was one of the very few front wheel drive cars in its class. It had disk brakes in front and four wheel independent suspension. This was heady stuff for a Japanese manufacturer at that time. And of course, it featured an air-cooled engine, mounted transversely at the front of the car.
The fact that it was an inline air-cooled four cylinder engine was not remarkable. This had been done before. But the engine was nevertheless notable for two reasons. (1) the technology employed for cooling the engine was both strange and unique, and (2) it was ridiculously powerful for its size.
Soichiro Honda knew that a noisy engine would not be acceptable for a world class car. And air-cooled engines have a reputation for noise due to the resonances of their cooling fins and lack of water jackets to dampen miscellaneous vibrations. So he drove his engineers crazy with all kinds of ideas to overcome these problems.
Instead of relying on long, thin cooling fins, his engineers specified short stubby ones shaped with curves and waves to suppress harmonics. The blower fan had short blades for the same reason. But what really made the 1300 engine so unique is that the engine block had cast-in airflow jackets, rather than sheet metal shrouds, to direct the cooling air around the heads and cylinders. And the jackets were ribbed, internally, to further exchange heat with the cooling air.
If you look at the exterior of the block, you will see cooling fins. But these are not on the cylinder barrels or heads. They are on the exterior of the cooling jackets.
The castings were in aluminum, of course, and were intricate to the extreme. It must have cost Honda Motor Company a small fortune to build each one.
The 1300 was available in two series, the 77 Series with 100 horsepower; and the 99 Series offering 115 horsepower. That’s 115 horsepower from an engine with a displacement of only 1,300 cubic centimeters (79 cubic inches).
How in the world did they do it? Well, this was basically a little racing engine, with an overhead camshaft, four Keihin carburetors, hemispherical combustion chambers, and dry sump lubrication system. Peak power was delivered at 7,300 RPM. It combined all the best of Honda’s motorcycle and Formula 1 racing experience.
Soichiro Honda was entering his 60s during the design phase of the Honda 1300 and he evidently saw this project as his pièce de résistance. It was the last engineering project he would ever lead. He drove his engineering staff to near mutiny with design changes even after the production line started rolling. Working from 5 AM to midnight every day, some of the workers were suffering from sleep deprivation, even falling asleep in the men’s room.
So, if the Honda 1300 was such a master piece, why don’t we hear about it today?
There are several reasons. It was more expensive to buy than similar-size cars in Japan. It was more expensive to make than it was to buy. And for all its’ engineering innovation. the little air-cooled engine turned out to be heavier than expected. The car was hard to steer and hard on front tires.
The Honda 1300 was sold in several countries around the Pacific Rim, (most notably Australia and, of course Japan). But it never made it to Europe and the Americas.
In 1973, Honda replaced the 1300’s air-cooled engine with a water-cooled fuel-injected variant which held things over until the introduction of the wildly-successful Honda Civic. And that was the end of Honda’s foray into air-cooled engines for passenger cars.
Citroen GS.
Citroen occupied two segments of the market in Europe. At the top was the DS series, known for its advanced hydro-pneumatic suspension. The DS had sleek if somewhat strange styling which was considered quite sensational when it was introduced in 1955. Although they were front wheel drive, they were powered by conventional water-cooled engines.
But Citroen also had plenty of experience with air-cooled engines, too, for its entries at the bottom rung of the market had been around for a long, long time. Citroen introduced its 2CV series way back in 1948 as a “people’s car” for France and the slightly larger Ami had been around since 1961. Both were powered by tiny air-cooled two-cylinder boxer engines.
So, while Citroen had cars for rich and poor, it had nothing to offer for Europe’s middle class which was expanding fast in the mid-1960s. Other manufacturers, like Renault and Fiat were cashing in on this market segment. Citroen needed a contender and so the GS was born.
Citroen had a reputation for bucking convention in the 1960s, and the GS was no exception. Like its big brothers, the GS had hydro-pneumatic suspension for a soft cushy ride, front wheel drive, and aerodynamic styling. It also had four wheel disk brakes. But unlike the upscale DS, the GS had an air-cooled boxer engine, a nod to its smaller siblings. And what an interesting little motor it was!
It was only the size of a Volkswagen Beetle engine in terms of displacement, and like the Volkswagen, it was a four-cylinder engine. Anybody familiar with a Beetle or Corvair engine would immediately recognize the basic layout, with a split crankcase, individual cylinder barrels and bolt-on heads.
But the GS engine was more sophisticated. It had an overhead camshaft driven by a cogged belt for each cylinder bank. This allowed hemispherical combustion chambers with relatively large valves.
The cooling fan was mounted directly on the crankshaft, so their was no fan belt. The crank shaft was a built-up affair, which enabled the use of one-piece connecting rods and journal bearings for lighter rotating mass; the one piece rods eliminated the need for connecting rod caps and bolts.
A two-barrel Solex carburetor was used, mounted on a central manifold with four separate tubular runners to the cylinders, much like one of those after-market center-mount carb conversions that were marketed for Volkswagens and Corvairs.
Initially, the carb base was heated with engine oil to prevent icing, but this didn’t help much when the engine was cold, so Citroen replaced it with a setup that routed a bit of engine exhaust through the carb base.
These were small engines, and when introduced, displaced only 1,015 cubic centimeters. Citroen made them small for taxation purposes in France. Later, in the mid 1970s, they were bumped up to 1,129, 1,222, and 1,299 cc.
Power ranged from a mere 56 hp (DIN) to 66 hp, but the little engines revved happily at highway speeds and, according to anecdotal information, could easily be revved to 8,000 RPM with no damage.
You might be thinking that a car with such radical features would be a flop in the market, but Citroen built and sold 2,474,346 of its GS series cars between 1970 and 1986. But sadly, few remain on the road today. Although the engines were strong, the cars were not rust proofed very well and many simply rotted away!
The preceding article was inspired by End of an Era: The Last Air-Cooled Automobile Engines, by James Kraus. For a full list of references, please contact the author, Allan Lacki.
Nice, but there was also the Tatra 613 with an DOHC V8 which came out around the same time.
Hello Mr. Turtle, Yes, you are correct. The Tatra 613 was introduced even later than the two cars described in the article, and the DOHC engine was new. And not only was it air-cooled, but it had the engine in the rear, too. Such an interesting car! But from everything I have read, it was built exclusively for government officials and was not offered for sale to the general public back in the 1970s. Not even in its native Czechoslovakia. If I am wrong, then please correct me. But that’s why I left it out of the article. Al Lacki
That’s essentially true, until 1990, when the Iron curtain came down and Tatra tried (unsuccessfully) to compete against BMWs and such with the 613 on the open market. But originally, it would probably have been difficult for a private citizen to buy one.
Wasn’t the DOHC V8 in T613 based on older OHV V8 from T603 (1956-1975) and T87 (1936-1950)? Or completely clean sheet design?
I recalled my friend in Texas telling me about it about thirty years ago. He said Tatra had made extensive modifications to V8 for 1975 launch of T613 while the V8 from T87 was carried over to T603 with few modifications.
Perhaps I got few details fuddled up in my head…
It’s a question I pondered too, and was not able to get any easy answers to. In looking at them from the outside, it’s clear that there are very substantial differences, such as the cooling fan and location of the distributor, etc.
But even if it was a substantially new engine, it no doubt built on all of the extensive experience of the older Tatra V8s; it’s an evolution of some sorts.Let’s put it this way: it’s not like the Tatra engineers were able to give themselves amnesia about an similarly-sized air cooled V8 they had been building for decades. Based on that assumption, I don’t consider it a totally “new” engine.
The mirror placement should have given it away as from Japan, but from the shape I immediately thought Eastern Europe on the Honda. An air cooled engine in that context makes sense. The noise is there on purpose so people know when not to turn around has Der Kommissar is in town.
This must have been quite the vanity project for Mr. Honda. The finned castings indeed look impressive, but to a potential buyer 4 carbs must have been terrifying. I know it was 1970 and hp per cubic inch was a big deal, but practical?
Thanks for telling this story, I had not heard of this model.
Yes, it turned into a vanity project for Honda,although I doubt that’s hat he had in mind. It really was not a good idea,in terms of the market at large, and its demise was inevitable. There’s a reason it was the last project he directed personally.
I only knew about the Honda 600’s air cooled engine until now. Mr. Honda was never going to win air vs. water cooled in the long run, but a lot of smart thinking and clever engineering still made for an amazing engine just the same. And the flat four OHC Citroen that is sort of a combination VW Type 3/4/Corvair/356 Carrera engine is really interesting. And almost 2.5 million of these engines were built! Great write up.
I think the last air coiled new car is the Citroën Visa, built from 1978 to the late 80’s (although without the air cooled engine anymore). Even if the VISA engine was similar to the old 2CV engine, it had a lot of differences and improvements, like an electronic ignition.
When the Fiat Panda was introduced in 1980, the Panda 30 with an air-cooled twin cylinder engine was offered in some markets.
That must have been an evolution of the 500/126 twin.
You’re right. I thought they made a transverse version for the Panda 30, but it turns out that the Panda 30 had a longitudinally mounted engine, like the 126. It was just turned around to sit in the front of the car. Perhaps it turned backwards relative to the 126, but it was otherwise similar. At least they didn’t do what Renault did and mount the engine behind the axle when reusing rear engined components.
It would have been extremely easy for Renault to flip the drive train. The reason the did it that way was because it was a French tradition,going back to the Citroen Traction Avant. The reason being that FWD cars generally struggled with heavy steering back then, and they didn’t want to make it worse by hanging the engine in front. It seemed like a better compromise, and it did result in better weight distribution and a longer wheelbase, which was also an important factor in achieving that famous “French ride”.
Audi pioneered the concept of putting a four cylinder four stroke engine in front of the axle, and it was a bit controversial. And they were the only ones to really stick with that over the long haul, although Renault did of course use it too for a while, later on.
Wonderful article. That Honda engine is wild and new to me.
Citroen experimented with flat 4 and 6-cylinder air cooled engines ahead of the front wheels when developing the DS, but according to an article in Citroenet, “The project was abandoned in 1954 due to lack of power, excessive thirst and great weight despite the widespread use of aluminium.” It’s a shame, since the production inline 4 behind the front wheels made a huge intrusion into the passenger compartment.
My understanding was that the DS took a lot of money to develop, and the cash wasn’t really there to build a new motor as well.
On my 1st of 3 deployments to Japan while in the Navy I discovered a co-worker had one of these 1300 Honda sedans. I had no idea it was air-cooled until I read an article in a British classic car magazine a few years ago. And I had always thought Honda’s 1st “big” car was the Civic.
This is the 1st account I’ve seen/read that goes into this car’s unusual/advanced engine design in such detail…..EXCELLENT EFFORT.
I had always been led to believe that Honda “gave up” air-cooled engines due to tightening emissions standards….but now I know otherwise.
So am gonna assume the Honda 1300 had a pressed together roller bearing crankshaft? I seem to recall the Honda CB750 motorcycle was their first engine that used oil pressure fed plain bearings.
It had plain bearings.
Thanks for this, I had no idea this Honda existed. I see hints of contemporary Vauxhall and Volvo in the sedan styling. The coupe is beautiful.
My thoughts too. The coupe is gorgeous, while the sedan looks kind of like a horizontally squashed HC Viva.
Mr. Honda was as demanding on his engineers as Carl Kiekhaefer, of Mercury Outboard, was on his. But that is how you win. And Mr. Honda also said, without failures, you cannot have success.
Great piece. I’ve just been reading a book on Honda (Driving Honda, Jeffrey Rothfelder, pub. Portfolio Penguin, 2014) in which the ‘confrontation’ between Soichiro Honda and financial saviour/CEO Takeo Fujisawa over Soichiro’s insistence on air-cooled culminated in Soichiro stepping back from his rigidity on the issue. As a conciliatory gesture, Takeo said; “Honda-san, I want you to know that I’ll quit when you quit.” Which they both did upon the successful launch of the CVCC engine.
https://www.curbsideclassic.com/curbside-classics-asian/curbside-classic-1973-1979-honda-civic-the-second-little-revolutionary/
Interesting as always.
What really surprised me was learning that there was only 7 years between the 2CV and the DS. To me the DS looks more like it’s early ’70s, though that could have something to do with when I first saw one – in roughly 1972, in the parking lot of the old original LL Bean store (when it was above their factory, and you had to take a really long staircase to get to it). Vacation/road trip + fun place + unusual car == indelible memory for a 10 y.o. motorhead!
(Sadly, the LL Bean original store (and factory) are gone now, and indeed the entire town of Freeport is now one big outlet mall.)
The 2cv was introduced to the market in 48, but it was a prewar design. And the difference between the DS and 2CV is not so much time as market. The 2CV was conceived as “an umbrella on wheels,” one step beyond a golf cart.
the Honda looks like an alternate universe Morris Marina
The front clip on the top Honda pic is a nice Triumph Toledo homage. Or was it the other way around? Fascinating article.
Good call on the Toledo. The coupe seems have been looking at the 61 F1 Fezza (and Nuccio’s personal 250GT ride), but there was also them ponchos.
Last air cooled car engines? I thought that Porsche was the last holdout…the 911 was air cooled up until 1998. Or am I misunderstanding something? Maybe these were the last time an all new design was brought out?
Title specifies ‘new’ air-cooled engines
The red Honda sedan has a front panel straight from a Marina van the coupe has an aire of Subaru about it, still the air cooled four is a new one on me they may have sold around the Pacific rim but I dont recall ever seeing one either in Aussie or here. The Citroens are about though not in any significant numbers rust took most of them out years ago.
The Hondas are still around in small numbers in Australia, I remember seeing them for sale fairly regularly 15-20 years ago when the paper Trading Post still existed and it was arguably easier to browse random old cars.
I had no idea the engine castings were so intricate!
They were very uncommon when new, in Melbourne at least. IIRC back then Honda had separate distributors for each state. I’ve only ever seen coupes, never a sedan.
Those engine castings are just amazing. Truly a work of art.
The Honda is completely new to me, and those castings look gorgeous, almost artistic. 4 carbs would seem to be a challenge though….was fuel injection not considered instead?
Yes, the front clip does look a bit Triumph Toledo and also it looks a bit stuck on and not blended with the front wings. Do we know who styled it, as it looks very late 60s Mazda and Fiat to me.
The GS was a great car – perhaps the last great fling of non-conformity in Europe before the Golf dictated the format, and doing with 1015cc what others 1300 or1500 for. There are very few left anywhere, though I have a GSA estate (with an even better interior!) in the files….
As far as I know, Hondas of this period were styled in-house; there’s not even the suggestion of a carrozzeria doing this sotto-voce.
The first Honda I can find to have ‘external’ styling input was the 1983 cabrio version of the City/Jazz by Pininfarina and that was really only a deroofing of the in-house tintop shape.
Why are four carbs a challenge? Millions of Honda, Kawasaki, Suzuki and other four cylinder bikes used the same set-up for decades. To my understanding, it was a very reliable and unproblematic arrangement.
I guess that’s my lack of motorbike knowledge coming out again! If Honda can make it work on bikes, then clearly it’s an easy read across to this car.
I’ve heard and read so many tales of getting triple carb (and even twin carb) cars running well that 4 carbs sounded even worse.
Would this set up have been 1 carb to each cylinder?
(For the avoidance of doubt, I have been on a motorbike. but only riding pillion in Mumbai…..)
4 SU carbs would have been a challenge, but fixed-jet carbs would not need to be balanced.
And you are correct Paul. I think the four carb thing probably started from British machine owners who could not keep their twin carb setups in sync. The Japanese setups, both in 2 carb or 4 carb, or even 3 carb, as used on the Yamaha XS750, were stone reliable. The British SU carbs would go out of sync between stoplights. And we wont even mention Bing motorcycle carbs.
Amal-Mikuni. SUs were used on cars not bikes balancing every 10,000 miles or so was usually enough
I would GUESS the styling of the nose/grille area on the Honda sedan looks “stuck-on” due to the propensity for many Japanese cars to adopt a (slightly) different “look” for different markets and/or home market sales outlets.
The green car at the top and the red car below it use the same basic shell. Yet I seem to remember my co-worker’s sedan having the nose treatment used by the 2 door hardtop.
30 years ago that Honda 1300 was fairly rare in “oour” area of northern Japan. I would imagine finding a sedan nowadays would be difficult while the coupe is a bit less difficult to find.
Just did a quick goggle and couldn’t find a sedan with the coupe nose, although both bodies seemed to come with either rectangular or round headlights.
Wiki serves up this:
‘It was reported at the time that launch was delayed by a couple of months because company president Soichiro Honda found the styling of the car as presented at the Tokyo Motor Show the previous year unacceptably bland and called for a redesign. It was not lost on contemporary commentators that Honda himself at the time owned and frequently drove a Pontiac Firebird, and the split air intakes on the front of the Honda 1300 as it came to market suggest that Honda design personnel were also aware of the boss’s fondness for his Pontiac.’
Which might explain this…
The resemblance of the Honda to the Morris Marina in uncanny – even down to the windshield shape. Coincidence or crib?
must be coincidence – sounds like the Honda came first. Cant imagine BMC copying anything good or bad.
there is a whiff of this also
the Viva HB was 1968….
or even earlier than that
67
I love that Citroen power unit–drop the whole thing and multiple services can be done at once–tune-up, brake job and trans service. The Driving Honda book is very interesting–Mr Honda made his first motorized bicycle basicilly because he was tired of hearing his wife bitch about walking to the market every day–before that he made a small fortune from selling his piston ring company and blew it all with wild partying.
Yep, I was surprised how party Soichiro Honda actually was.
Interesting article!
But I’ll keep my older air cooled car:
I’m quite jealous, Mark!
Wow ~ I’d never heard of this Honda car before , too bad we never got a chance to buy it in U.S.A. but it wouldn’t have sold well I’m sure .
-Nate
The GS was a very nice car, smooth engine, great suspension, and overall maybe a better car the the competition had to offer at the time. I owned one, around 1986, and wouldn’t mind driving it today.
Don’t forget the air cooled diesels that Deutz came out with. They tried them on some concete trucks in Baltimore and they were peppy. One of the drivers got a ticket going 70 (55 mph days) up a steep hill loaded on I-83 that most trucks are down on their knees and bog down to about 20 mph
Learned something about the Honda, thank you! The Citroen 1015 was also fitted in the Ami Super between 73 and 76. I can confirm the anecdote – it will pull 8000 rpm although not much happens except noise after 6750.
But its not a durable engine, being prone to oil leaks from the return tubes from the heads to the sump, poor lubrication of the camshafts when cold leading to premature wear and also internal corrosion as more water is produced from combustion again when cold, which causes the carburettor hotspot and the exhaust pipes that feed it to rust through.
Why I have two of them still baffles me…
A neighbour had a GS when I was a teenager. I spent so much time checking out that car!
Two Ami Supers? Fun! I reckon you’d know the 1015 pretty well by now…..
Great article, huge fan of both of these cars!
Roy D Haynes styled the Marina for British Leyland – it was not a BMC car, far too regressive technologically though Haynes did a tidy styling job – he was ex-Ford. Be interesting to see where the Honda look came from.
The Marina was a Leyland car – Stokes had a lot of faith in it. But BMC could do regressive – the A55/A60 saloons, arguably the Marina’s direct predecessors, were distinctly short of technological innovation.
I had no idea what the green car was before reading the article–I’d seen photos of the 1300 coupe before, but never the sedans. And that engine! What a technical marvel, and 115 HP out of an air-cooled 1.3 in the late 60’s is quite remarkable.