In the sixties and early seventies, that golden era of V8 muscle cars, the lowly six cylinder engine was typically looked down on as a slug, often for good reason. We were steeped in the stereotype of the lowly, pokey six, the engine for spinsters and skinflints…and even our parents. But there were some surprising exceptions—the right six in the right car could out-accelerate many typical V8 cars of the times. Of course with some judicious modifications, they could really scoot, but we’re going to stick to strictly stock ones in this exercise to find the quickest pushrod inline six cars of the sixties and seventies.
Could they even break the ten second barrier in the 0-60 mph sprint? That was the benchmark for a quicker-than-average V8. Let’s find out.
First, a quick bit of six cylinder history.
The inline six has a number of intrinsic qualities that made it the most common engine by far in the US for much of the 20th century. Most importantly is its inherent balance, which makes it significantly smoother than the fours that had dominated the low price field up until 1929. That’s the year Chevrolet introduced its first “Stovebolt” six (above), a 194 cubic inch ohv unit with 46 hp. It was replaced in 1937 by the Blue Flame six, which in turn was replaced by the new Turbo Thrift family in 1962-1963, with 194, 230, 250 and 292 cubic inches, the last one only for trucks.
Plymouth replaced its four with a new flathead (side valve) six in 1933, a 189.8 cubic inch unit with 70 hp. The same basic engine would be used all the way through 1959 in various displacements, replaced in 1960 by the slant six made in 170, 198 and 225 cubic inch versions.
Henry Ford’s 1906-1908 Model K had a six cylinder engine, one of the first in the US. With 405 cubic inches and 40 hp in a 2500 lb. car, it was exceptional quick for its time. Although the K sold reasonably well for its price class, Henry somehow became disenchanted with the big and fairly expensive six and moved on to much cheaper fours, until he introduced the first low-price V8 in 1932. Ford did also offer sixes again starting with a new flathead six in 1941, which was replaced by a new ohv six in 1952. In 1960, the first of the all-new lightweight Falcon sixes appeared, built in 144, 170, 200 and 250 cubic inch displacements. In 1965, the 240/300 “Big Six” was introduced and replaced the older large 226 six in full size cars and trucks.
Nash built side valve sixes and eights going back to its earliest days. In 1941, the new smaller unibody Nash 600 had a new six, with 172.6 cubic inches and 75 hp (above). This basic engine in various displacements was built until 1965, the last flathead six in a passenger car. An ohv development of this engine, with 195.6 cubic inches, was built from 1956 through 1965, after which it was replaced by the new family of AMC sixes, with 199, 232, and 258 cubic inches, and then developed into the Jeep 4.0 six, built until 2006, the last of the classic inline sixes.
The modern V8 era in the low-price segment started in 1954 with Ford’s Y-block V8 and really took off in 1955 when Chevrolet introduced its iconic small black V8 and Plymouth offered two of Dodge’s smaller V8 engines. V8 adoption in these low-price cars increased steadily from their introduction through the end of the sixties, as the full size cars got bigger, heavier and ere increasingly ordered with power-robbing power assists and accessories. In 1960, 56% of full-size Chevrolets came with a V8; by 1970 it was 97.5%.
It’s easy to see why. By 1960, a basic large Ford weighed some 3700 lbs compared to 3000 lbs for a 1950 Ford. In a vintage road test, a 1960 Ford with the 226 cubic inch six and three-speed manual took 18.6 seconds for the 0-60 sprint and the 1/4 mile took 21.6 sec. @65 mph. With the two-speed Fordomatic, it would have been somewhere over 20 seconds. This was marginally adequate as long as the expectations were quite modest and the loads (or hills) were not great. But load up the kids and the trunk and passing on two lane highways became dangerous or impossible and driving in the mountains was an exercise in patience or futility.
There were some exceptions, the most notable by far being the 1953-1955 Hudson Hornet, which had a large 308 cubic inch flathead six that was essentially a new engine, and quite potent for its configuration. With the optional Twin-H dual carbs, it made 170 hp and in a vintage review, it did the 0-60 in a quite brisk (for the times) 12.2 seconds and the 1/4 mile in 18.5 seconds. The Hornet had a spectacular—if short—career in NASCAR stock car racing racing.
The lighter compacts that started to appear shortly after 1950 offered some scope (and hope) for improved performance with sixes. The standout was the 1954-1955 Willys Aero, which in those last two years of its too-short life was available with the larger Kaiser 226 cubic inch flathead six with 115 hp. That would have given it an as-tested (∼300 lbs above curb weight) power-to-weight ratio of 26.4 lbs./hp, which should have resulted in a 0-60 time of some 15-16 seconds, quite decent for the times.
Even the 100″ wb. 1959 Rambler American with its elderly 90 hp flathead six managed a pretty decent 0-60 time of 16.0 seconds in a Road & Track road test. That’s several seconds better than that 1960 big Ford six.
Expectations were dashed with the new 1960 Falcon, which weighed as little as 2540 lbs. and had a brand new ohv six. But the 90 hp 144 cubic inch six was not up to the job; with the three-speed manual, its 0-60 time was close to 20 seconds, and with the new 2-speed Fordomatic, it was about 25 seconds. That was in the same ballpark as a 36 hp VW Beetle back then.
The larger 101 hp 170 cubic inch version that arrived in 1961 helped, bringing the 0-60 time down to a more reasonable 17-18 seconds. The Falcon six had a head that had very small valves and ports and an integrally-cast log intake manifold that hampered breathing, and would do so for the rest of its life in the US, even though the head did eventually get slightly larger valves.
On the other end of the spectrum, the 1960 Valiant’s new 101 hp 170 cubic inch slant six looked to be a winner, with its 12-port head and long intake runners. But two different vintage reviews of a manual-transmission version suggest it wasn’t quite as brisk as might be expected or as it’s often been made out to be: Motor Life got a 0-60 time of 16.7 sec.; Motor Trend’s did it in 17.2 seconds, or about the same as the 170 cubic inch Falcon. A vintage review of a 1961 Lancer with the 170 slant six and the Torque Flite automatic yielded a 0-60 time of 21.9 seconds, also a bit slower than I might have expected.
But an exciting chapter in the history of the slant six was opened when NASCAR announced a racing series for compact cars. Chrysler jumped in with both feet, the result being the Hyper Pak, a set of parts available over the parts counter that included a new intake with a four barrel carb, high compression pistons, a racing camshaft, exhaust headers, stiffer valve springs and a few other tweaks that bumped the 170’s power to 148 hp.
This made the Valiant the undisputed top dog of the series, with a top speed of 130 mph and able to walk away from the Falcon and Corvair, which both also got some modifications but not with nearly the result of the Hyper Pak Valiant.
The Hyper Pak kit could also be installed in the larger 225 cubic inch slant six, resulting in a 196 hp rating. Obviously, a Hyper Pak Valiant would and should have been a contender for this whole undertaking, but it’s not being considered as this was not a stock engine available from the factory; one had to buy the parts and install them after buying the car; that’s a disqualification.
And somewhat curiously, the one vintage review we have of a 1961 Lancer with the 225 and Hyper Pak turned in some disappointing numbers: 0-60 in 11.8 seconds and the 1/4 mile in 18.5 @74. But that needs to be qualified: the test involved converting a stock 225 with Hyper Pak parts but it’s not clear whether that included the high compression pistons. And this car was equipped with the Torque Flite automatic.
It’s quite safe to assume that a 225 Hyper Pak in full kit and with the 3-speed manual and aggressive rear axle gears would readily break the 10 second barrier in the 0-60 dash.
Speaking of disqualified cars for this contest, there’s also the Corvair. Why? I wanted to focus on inline sixes, and because the Corvair engine was of course the beneficiary of an ongoing development program to increase its output, including turbocharging. From its original 1960 hp rating of 80 it got boosted to 180 hp in the 1965 turbocharged Corsa. But straight line acceleration was never really the Corvair’s forte; it was more fun (and potentially thrilling) on a curvy road. The 1960 Corvair’s 0-60 times were between 19.5 and 16.4 seconds, depending on the transmission, with the Powerglide actually being two seconds quicker than the 3-speed manual.
Those numbers improved steadily as the Corvair’s engine got more displacement and power. By 1961, the 0-60 time of a higher output 98 hp with the 4-speed dropped to 13.2 seconds. In 1962, the new turbocharged Spyder was tested by M/T, but it only improved slightly in acceleration, to 12.5 seconds (0-60) because the turbo lag was so great. And even the ultimate version, the 1965-1966 180 hp turbocharged Corsa was not able to break the 10 second barrier, with three different vintage reviews resulting in 0-60 times of 10.0, 10.2 and 10.9 seconds. It was a wonderful handling car, and once under way at higher engine speeds, the turbo worked well, but not from a standing start.
The Pontiac OHC Six is also not a contestant here, hence the word “pushrod” in the title. Yes, in its Sprint version, with a four barrel carb, high compression and a few other tweaks, it was rated at 207 hp (1966) and 215 hp (1967-1969). We have three different vintage reviews of Sprints here, and the 0-60 times range from a quite quick 8.8 seconds from a ’67 by Car and Driver, which had a rep for really abusing their test cars, a 10.0 seconds for a ’66 Sprint, and 10.1 seconds for a ’67 Firebird Sprint.
Not to give credit where it’s due, but the Pontiac OHC six was not really all that ambitious; it was based on the Chevy six, did not have a crossflow or hemi head, its valves and porting were not very large, and most importantly, it had a fatal flaw in its lubrication system that killed them all too soon. A Chevy six (or the AMC six and Ford big six) could readily have made comparable power with a few key modifications. And the Pontiac OHC six never really found a proper home; it would have needed to be in a lighter car than it was used in to really shine.
Obviously the Buick V6 is also not invited to this party. Why? It did get turbocharging in 1978, which gave it a sub-10 second 0-60 time (9.5 seconds in the 1979 Riviera GS). But it’s not like the earlier versions were a threat to the fastest inline sixes. A ’62 Special with the 135 hp 198 cubic inch version had a 0-60 time of 13-14 seconds, and it wasn’t any quicker when its displacement was increased to 225 cubic inches and power upped to 155 hp in 1964 because the new A-Bodies were bigger and heavier.
Enough with the preliminaries and disqualifications. Let’s take a look at our contenders. The following table lists the quickest six cylinder car road test results I could find. It’s certainly possible that there’s others out there that I don’t have or are not available on the web. The are ranked fastest to slowest based on their 0-60 times.
| Year/Model | CID/HP/Torque | Transm. | Tested Weight | lbs/hp - lbs/torque | 0-60 | 1/4 mile |
|---|---|---|---|---|---|---|
| 1971 Gremlin | 232/135/215 | 3M | 2803 | 20.8 - 13.0 | 10.5 | 17.8 @76.1 |
| 1965 Rambler American | 232/155/222 | 3A | 3178 | 20.5 -14.3 | 10.9 | 18.3 @76 |
| 1967 Camaro | 250/155/235 | 3M | 3408 | 22.0 - 14.5 | 11.2 | 17.2 @81 |
| 1962 Valiant | 225/145/215 | 3M | 2945 | 20.3 - 13.7 | 12.3 | 19.6 @74 |
| 1964 Rambler Classic | 232/145/219 | 3A | 3135 | 21.6 - 14.3 | 12.6 | 19.3 @73 |
| 1963 Dart | 225/145/215 | 3M | 3160 | 21.8 - 14.7 | 13.3 | 19.3 @72 |
| 1964 Chevelle | 230/155/215 | 2A | 3585 | 23.1 - 16.6 | 13.4 | 19.6 @72 |
| 1962 Chevy II | 194/120/177 | 2A | 2900 | 24.7 - 16.4 | 14.0 | 19.2 @69 |
| 1963 Dart | 225/145/215 | 3A | 3220 | 22.2 - 15.0 | 14.3 | 20.1 @68 |
A few comments on these: this whole exercise started when I wrote up the Vintage Review for the 1965 Rambler American 440-H with the new AMC 232 six, the 155 hp version with a two barrel carb. Despite being saddled with the Borg Warner automatic, it zipped through the 0-60 time in 10.9 seconds. I was a bit surprised and it made me wonder what a manual transmission version could do, as well as wonder what its competition could do.
Clearly, the Gremlin was a serious contender, as it was also available with the larger 258 inch version of the six. The top two spots held by the AMC six is not surprising, as it was one of the last new sixes in the US and benefitted from experience, including relatively large valves and ports. It has an excellent reputation and is easily hopped up for more power. And Ramblers tended to be light.
The #3 ranked ’67 Camaro 250 six tested with the three-speed manual did not surprise me either, as the Chevy 250 six has proven to be a strong runner in several road tests; it propelled a full-size ’66 Bel Air with Powerglide to a 0-60 time of 15.5 seconds, only 3/10th of a second slower than a ’64 big Ford with the 289 V8 and 3-speed automatic. In a lightweight Chevy II body, it could clearly be a serious contender.
Some might be surprised about the 225 slant six not having better numbers in road tests, but there seems to be a pattern. It’s got a lot of strengths, but it is an older design and it has the smallest valves of all of these four six cylinder families (the AMC has the largest). Its head was designed for the fairly small-bore 170, and then the block was raised to accommodate a large increase in stroke; that limits its potential somewhat.
The Classic is there to confirm how well the 232 runs, even with the one-barrel, automatic and in the heavier Classic body. The Chevelle and Chevy II are there to round out the field, and show how well even the small 194 inch Chevy six ran in the company of these larger engines.
As I mentioned previously, these are the road tests of the quickest stock sixes I could find. And since the optimal combinations of engine, transmission, rear axle ratio and body style weren’t ever tested, I’ve put together what I consider the top ten contenders for the crown below, and used a performance simulator at automobile-catalog.com to estimate their 0-60 and 1/4 mile times.
These performance simulators are obviously not perfect, as they just calculate certain vital stats to arrive at their numbers. I did cross check a few cars from the vintage reviews above; some were almost identical, others tended to be estimated a bit faster. On the other hand, since the calculator only uses the standard axle ratio, some of these cars below could possibly be even quicker with an optional higher-numerical axle ratio.
So here they are, the contenders for quickest sixes. I included two Ford 250 six cars, the 1969 Mustang and the 1971 Maverick, because I knew that the Maverick’s light weight would give it a good power-to-weight ratio and the Mustang was also reasonably light.
| Year/Model | CID/HP/Torque | Transm. | Test Weight | lbs/hp - lbs/torque | 0-60 (sec.) | 1/4 mile |
|---|---|---|---|---|---|---|
| 1966 Rambler American | 232/155/222 | 3M | 2854 | 18.4 - 12.9 | 9.3 | 17.4 @80 |
| 1967 Chevy II | 250/155/235 | 3M | 2940 | 19.0 - 12.5 | 9.5 | 17.4 @78 |
| 1964 Chevy II | 230/155/215 | 3M | 2845 | 18.3 - 13.2 | 9.5 | 17.5 @77 |
| 1965 Valiant | 225/145/215 | 4M | 2900 | 20.0 - 13.5 | 9.6 | 17.3 @78 |
| 1971 Gremlin | 258/150/240 | 3M | 2803 | 18.7 - 11.7 | 9.6 | 17.5 @77 |
| 1967 Camaro | 250/155/235 | 4M | 3070 | 19.8 - 13.1 | 10.1 | 17.6 @78 |
| 1969 Mustang | 250/155/240 | 3M | 3030 | 19.5 - 12.7 | 10.1 | 17.8 @77 |
| 1962 Valiant | 225/145/215 | 3M | 2820 | 19.4 - 13.1 | 10.2 | 17.4 @78 |
| 1971 Maverick | 250/145/232 | 3A | 2925 | 20.2 - 12.6 | 10.7 | 18.0 @75 |
And the winner is:
#1: 1966 Rambler American 220 2-door sedan 232 with 155 hp 232 six, 3-speed manual. 0-60 in 9.3 seconds; 1/4 mile in 17.4 secs @ 80 mph
This whole thought experiment was triggered by the Vintage Review of the 1965 Rambler American 440-H hardtop with the brand new AMC 232 six. It had the optional two-barrel 155 hp version, teamed with the Shift Command Flash O Matic automatic, built by Borg Warner. Despite the automatic, which actually worked quite well and a number of other options that resulted in a test weight of some 3200 lbs., the results were an eye-opening: 0-60 in 10.9 secs., and the 1/4 mile in 18.3 @76. That was typical small V8 territory.
So how about a stripper 220 with that engine? The listed base weight of the 220 2-door is given as 2554 lbs. I added 300 lbs to all of these cars for their “test weight”, enough for gas and a driver. That results in 2854 lbs., resulting in a most favorable power (both hp and torque) to weight ratio.
Here’s the simulated acceleration graph. I also ran this simulation with the 3-speed with overdrive, since it has a more aggressive 3.58 rear axle ratio. That resulted in a slightly better 17.3 second time in the 1/4 mile, but the 0-60 dropped to 9.7 seconds, because it required an upshift to 3rd gear just before hitting 60. So take your pick; either way, it’s a quick little Rambler.
#2: 1967 Chevy II 100 2-door Sedan with 250 six, three-speed manual. 0-60 in 9.5 secs., 1/4 mile 17.4 @78 mph.
Early on in this thought exercise, I debated whether the American or the ’67 Chevy II would win this contest; that was before I remembered about the Gremlin and the 4-speed Valiant. I assumed that the 250’s somewhat greater torque would make the difference, but not according to the simulator.
Here’s the graph. Note that these numbers are based on the stock 3.08 rear axle ratio; there was also a 3.58 optional ratio available, which would enhance its acceleration further, although that might require a shift from 2nd to 3rd just below 60 mph making the 0-60 time longer, as in the case with the American. But it would certainly enhance the 1/4 mile result.
#3 1964 Chevy II 2-door sedan with 155 hp 230 six, 3-speed manual transmission. 0-60 in 9.5 secs., 1/4 mile in 17.5 @77 mph
This was my original pick to take on the American and win before I considered the 250 being available in the ’67. It’s actually got the best hp-to-weight ratio of them all (18.3 lbs/hp), thanks to weighing about a hundred pounds less than the ’67 version.
That’s due to an unusual one-year-only higher-output version of the 230 six, available only on the ’64 Chevy II and Chevelle. A perkier camshaft and a bit of jiggering with the carburetor resulted in a 155 hp rating instead of 140 for the more common version. And it even came standard with a chromed valve cover and air cleaner! How unusual; even the big V8’s didn’t get that treatment.
The acceleration graph clearly shows how this higher-revving engine results in higher speeds at the shift points. Now this car would clearly benefit from a more aggressive rear axle ratio, perhaps even more than the 3.36 that was optional. And of course what would really make this sing as a four-speed manual. No such luck.
#4: 1965 Valiant V100 2-door Sedan with 145 hp 225 slant six, 4-speed manual transmission. 0-60 in 9.6 secs., 1/4 mile in 17.3 @ 78 mph.
I struggled with the slower numbers for the 225 slant six A-bodies, both in vintage reviews and the performance calculator. The best it came up with was 10.2 seconds for 0-60, for the slightly lighter ’62 Valiant. The 225 was simply a bit smaller and had less torque than the bigger sixes in the competition. Also, the 225’s head, the same as on the smaller 170, was a bit restrictive in the larger, long stroke 225. The valves were the smallest of any of these sixes. But then I remembered that Chrysler’s new A-833 four speed transmission was available on the A-bodies from 1964 to 1966. Aha!
The acceleration graphs tell the tale; the four-speed is on the left, the three-speed on the right. The lower gear ratios (3.09 first gear) and closer gaps in the 4-speed clearly result in brisker acceleration. The result is that despite having a worse power to weight ratio, the Valiant essentially ties the more powerful Chevy IIs, and actually ties the American with the lowest ET in the 1/4 mile, at 17.3 seconds. Is this actually the quickest six of them all?
It certainly would have been the most fun to drive. The three speeds back then all had unsynchronized first gears and the column shifters were invariably balky and decidedly unfun. The only thing missing is a more aggressive optional rear axle ratio; I didn’t see any listed in the brochure, I assume the standard one is the 3.31. That’s not too bad, actually, but a more aggressive ratio would have made it a bit quicker yet, given the slick-shifting Hurst stick shift.
#5: 1971 AMC Gremlin With 150 hp 258 six, three-speed manual with floor shift. 0-60 in 9.6 secs., 1/4 mile in 17.5 @77 mph.
The main advantage the Gremlin has is its power to weight ratio, especially its best lbs./torque ratio; admittedly that’s an unusual metric but I think it’s useful here. Undoubtedly the light Gremlin with the torquey 258 is a quick car. The only nagging question in my mind is to what extent the ’71 AMC six was impacted by its emission controls, which at the time almost invariably included less aggressive ignition advance curves and some rejiggering of the carburetor, none for the better.
And then there’s also the purely subjective and emotional factor: The Gremlin is just so audacious, a Hornet with its whole rear end cleaved off in a stroke of Dick Teague’s pencil. And there’s no doubt that compared to the 1971 Vega and Pinto, it was a veritable rocket, thanks to its big sixes. The 150 hp 258 with its beefy 240 ft.lbs. of torque was optional, and a floor shifter was standard with the three speed manual behind this engine. And thanks to its 58%/42% F/R weight distribution, burning rubber would have been all-too easy, even in second gear. Might that hamper its ability to actually equal or beat the other top runners-up?
As to its projected 0-60 time of 9.6 seconds, that was based on its standard 2.73 rear axle ratio. There were options for 3.08 and 3.31 gears, so it seems reasonable to assume it could actually hit that as per this simulated acceleration graph, or close to it with the 3.31 rear gears and…the floor shifter! C/D’s 232 Gremlin had the 2.73 gears and a balky column shifter. In any case, I’m pretty convinced that properly equipped, the 258 Gremlin would break the 10 second barrier in the 0-60 run, in the rear world.
Car and Driver ranked the Gremlin dead last in its 1971 comparison of six small cars, but it did say “Compared to the others, the Gremlin feels like a fuel-burning Hemi on the dragstrip“, which resulted in the 10.5 second 0-60 time and a 1/4 mile result of 17.8 @76.1 mph, the best time of any available tests of these cars.
Given its other many shortcomings, like an optional and essentially unusable rear seat, ponderous handling, lousy braking, very slow steering (6.25 turns lock-to-lock), and mediocre fuel economy (among others), it’s nice to think of the Gremlin being good at something other than just looking odd.
#6: 1967 Camaro with 250 six and 4-speed manual transmission. 0-60 in 10.1 secs., 1/4 mile in 17.6 @78 mph.
The Chevy didn’t get the four speed, but the Camaro did. Unfortunately, it weighs a few hundred pounds more, but it’s a contender, even if it’s not predicted to break the 10 second barrier as per the performance simulator.
Here’s the graph for it. It has the standard 3.08 rear axle ratio, and it looks like the shift into fourth happened just before it went through the traps in the 1/4 mile. That’s not good; it would definitely benefit from the optional 3.55 ratio, or even a steeper one, if it had been available.
Still, it’s a zippy car. Of course for the price of the four speed one could have just gotten the base 210 hp 327 with the three speed. But that’s not what this is all about.
#8: 1969 Mustang with 250 six and three-speed manual transmission: 0-60 in 10.1 secs., 1/4 mile in 17.8 @77 mph.
I’m a wee bit suspicious about the Mustang’s performance simulation. Why? The 250 six didn’t ever have a rep as a particularly lively engine; it was essentially a tall-deck Falcon 200 six with a longer stroke but the restrictive cylinder head was not improved. I may be wrong, but my guess it’s just not quite as powerful as the others here.
#9: 1962 Valiant with 225 slant six and three-speed manual transmission. 0-60 in 10.2 secs., 1/4 mile in 17.4 @78 mph
I had already included this before I remembered about the 4-speed later version. It’s a tad lighter, but has the three speed manual, although all these gen1 Valiants and Lancers had only floor shifters for the manuals. As a frame of reference, an actually tested ’62 Valiant did the 0-60 in 12.3 seconds, and two tested A-bodies with the 225 and Torqueflite had 0-60 times of 14.3 and 15.9 seconds.
#10: 1971 Ford Maverick with 250 six and three-speed automatic. 0-60 in 10.7 secs., and 1/4 mile in 18.0 @75 mph.
I decided to include the Maverick since it was quite light even though the 250 six was only available with the C4 automatic. The projected results are about what I would have expected. I drove a few of these when I was a car jockey at a Ford dealer and they definitely had a bit more grunt than the 200 with the automatic, but they tended to run out of breath pretty quickly. The emission controls in effect may have been making themselves felt, but that process was just starting.
Within four years, that 250 six would be making all of 70 net hp, at an absurdly low 2800 rpm in CA emission configuration. That turned the 1975 Granada into the slowest six cylinder car and winner of our “Most Malaise Car Ever” award. Its 0-60 time? 23.15 seconds. Right up there with the 1960 Falcon with the little 144 six and automatic.
Maybe that’s why I’m a bit leery of the 250’s abilities, even before it was strangled to near-death.
Meanwhile, in Australia the Falcon six was treated very differently, as in a continuous program to improve its performance. This is a 250 2V in a Cortina TC and originally used in the Falcon XY and XA. A crossflow head replaced this style in 1980, and a SOHC replaced that in 1988.
It culminated in the Barra 24 valve series that arrived in 2002 in the Australian Falcon. Its power started at 182 hp and culminated in the turbocharged Barra 325, as in its horsepower. Yes, these engines are a direct evolution of the 1960 Falcon six. As is the car, a direct evolution of the original Falcon. The Aussies worked wonders.
The Chevy 250 six also got some love in Brazil, although nothing as radical as the Falcon six in Australia. It did get fuel injection and a bit of modernizing and was good for 168 net hp (about 200 gross).
The AMC six had a long and successful life. In Mexico, it was built in various sizes, including the 4.6, with 282 cubic inches and as much as 200 hp. It had also had a different head with larger valves and ports. And I don’t need to show you a picture of the long-running Jeep 4.0 six, built from 1987 to 2006, in 177 and 190 (net) hp ratings. Folks now stroke them up to 5.0 liters.
Why weren’t sixes developed further in the US? Back in the ’50s – ’70s, the V8s were built in such huge volumes, so they only cost a small premium over a six. That kept sixes as the cheapest, low-end economy engine. And the one attempt to do otherwise, the Pontiac Sprint OHC six, wasn’t really a success in either its take rate, its suitability in the relatively heavy cars it was used in and in it durability, which was poor. But sixes did of course come to dominate, except they were almost invariably V6s.
The one exception was the GM Atlas engine family, which came in four, five and six cylinder versions, used in light trucks and SUVs. It had a fairly short life, from 2002 to 2012. The six made up to 291 hp.
And of course now Stellantis has a brand new inline six, the Hurricane turbo, with twin turbochargers and rated at 420 hp, with higher output versions to come.
Sadly my personal favorite six didn’t make it in the running, as the Ford 240/300 “Big Six” was only used in full-size cars (240) and trucks (240 & 300). It has a stellar rep and a very strong following, as its easy to coax more power out of it and aftermarket heads and all sorts of goodies to make 250, even 300 hp are available. As it is, it was the most powerful pushrod six of this period; the pre-emission controlled version of the 300 was rated at 170 gross and 150 net hp. That’s pushing right up into small V8 territory, and its fat torque curve made it better suited to trucks than the small Ford V8. If it had been available in a Falcon or Mustang or even a Fairlane, it would have clobbered all the rest here.
Like all Ford engines, its power was badly diminished in the Malaise Era, but in 1987 it was treated to a proper port fuel injection system and its rating went back to its original 150 net hp.
As a final note, I’d like to just post 0-60 times of a few cars with V8s from this era from vintage reviews, as a comparative frame of reference.
1963 Chevy Biscayne, 195 hp 283, 3-speed manual: 10.7 secs.
1964 Ford Custom, 195 hp 289 V8, 3-speed automatic: 15.2 secs.
1968 Plymouth Fury, 230 hp 318 V8, 3-speed automatic: 11.4 secs.
1962 Ford Fairlane: 145 hp 221 V8, 2-speed automatic: 15.5 secs.
1961 Chevy Impala, 170 hp 283 V8, 2-speed automatic: 12.2 secs.
1962 Ford Galaxie, 175 hp 292 V8, 2-speed automatic: 16.2 secs.
1961 Ford Galaxie, 300 hp 390 V8, 3-speed automatic: 9.8 seconds
1968 Chevy Impala, 200 hp 307 V8, 2-speed automatic: 13.8 secs.
1962 Chrysler Newport, 265 hp 361 V8, 3-speed automatic: 10.8 secs.
1967 Barracuda S, 235 hp 273 V8, 3-speed automatic: 9.2 seconds
1964 Plymouth Valiant, 180 hp 273 V8, 4-speed manual: 9.9 seconds
Related CC reading:
Vintage Car Life Road Test: 1965 Rambler American 440-H – Hot Six!
Curbside Classic: AMC Gremlin – 1971 Small Car Comparison Number 6
Engine History: The Quickest And Slowest Chevy Turbo-Thrift Sixes
Vintage Review: 1954 Hudson Hornet With Twin-H Power – The Flathead Six That Spanked The V8s
Great article, and I’ll give it a proper read later tonight.
The Holden “Red” motor and Chrysler Australia’s “Hemi” deserve a mention. The Red in it’s XU-1 from was a giant killer.
The 1972 Bathurst 500 is a prime example, and the XU1 still regularly beats all comers in historic racing.
I did my own thought experiment, wondering if the tech that has been applied to the latest small block OHC Chevy V-8s (direct injection, variable valve timing, cylinder deactivation) would produce a useful V-6 to be used in place of the turbo-4s or DOHC V-6 they use instead. I suppose the same tech could be used on an inline 6 as well.
If you take 3/4 of a 6.2 liter V-8 you’d have about 4.6 liters or around 280 cu in. 300-330 HP and 340 ft lb of torque should be possible, in a package several inches lower and possibly lighter than the 3.5 liter DOHC V-6, with a wide torque curve and good fuel economy. This seems like a good package for minivans, mid-size pickups and crossover SUVs. Or a mid-size or large sedan, if any American company other than Cadillac made one.
What do you think?
Some place I still have a copy of Hot Rod magazine from the mid 70s with a list of proformance parts and tips to hop up a Ford, Chevy or Chrysler inline 6. Also remember a guy with a slant 6 Dart that cleaned up the streets in the mid 70s.
I cycled through my mental catalog of the 40 or so running vehicles I’ve owned in my lifetime, and there’s only one straight 6 car (and one straight six pickup) on the list.
The 1979 Chevy C-10 with 250 & 3-on-the-tree was slow, but the engine was tired and eventually ventilated the block. I swapped in a (presumed) 307 V-8.
The only I-6 *car* wasn’t American and didn’t run on gasoline. It was a Swedish/German mashup. To wit, a 1984 Volvo 245 with the naturally-aspirated I-6 Diesel sourced from VW. It wasn’t going to make this list either, with a 0-60 time of “eventually”.
My Mom’s ‘65 Mustang was equipped with the 6 cylinder (200, I believe) and 3-on-the-floor and was an absolute fun little car to drive! So much so, that when I ordered my ‘73 Mustang convertible, it was with the same basic drivetrain…I expected similar driving fun. Not so much. The car seemed so underpowered and cumbersome compared to my Mom’s ‘65, but the top did go down, so that was it’s saving grace.
My ‘73 Mustang convertible…
For many, it’s easy to think that damn near all first gen Mustangs came with a small-block V8, but that’s far from the case. IIRC, it was something like a near 50/50 split of those early Mustangs having a six or 289, which makes a lot of sense when one considers that a lot of those Mustangs were ‘secretary specials’ that went to young women who didn’t care about performance so much as having a stylish car that had an easy-to-drive, practical side, too. Essentially a much better-looking Falcon Sprint (which is precisely what a Mustang was).
Iacocca sold a whole lot of automatic, six-cylinder ‘Stang hardtops.
Coincidentally, there’s a Vintage Review of a 1965 Mustang six coming up later this month. The six/V-8 split didn’t reach 50/50, but it was substantial.
The 1973 250 wasn’t any less powerful than the 1965 200, but the 1973 convertible was over 500 lb heavier than a 1965 hardtop, so the problem wasn’t too little power so much as too much Mustang.
Interesting, and well done AMC. When I said I’d like a 290 V8 and 4 speed in Jim’s Rambler article last week I had assumed that the 290 was lighter than the inline six, but it’s actually 100 pounds heavier.
When I had my 258 equipped Matador I briefly had a 2 barrel manifold on it, with a Carter carb off a 318 Mopar. It did result in better acceleration (17.7 second quarter mile with open exhaust) but I never got the throttle linkage sorted properly and it was very hard to drive smoothly.
The October 1969 issue of Rod & Custom featured an aftermarket “high altitude package” for Mexican built Ramblers that used a 4 barrel and tube headers.
I’ll just put this here..
It definitely belongs in this conversation, the sound these engines make with the twos wide open is something to be savoured. A hot Aussie Charger is high on my list of dream cars.The VH E49 gets 302 hp out of 4.3 litres with a four speed to boot.
The Triumph 2500i would compare well here. Motor tested one in October 1969 fitted with overdrive 4 speed and recorded a 0-60 of 9.7 seconds, standing quarter mile in 17 seconds dead (exit speed not recorded, but 0-80 was 17.1 sec.) with a recorded max. of 117.6mph. It certainly showed the benefit of fuel injection, even if it did prove less reliable than hoped.
It’s understandable but still sad how the domestic inline six engine would rapidly descend into being the red-headed stepchild of the auto world after the nearly as cheap to produce V8 arrived on the scene, first in the guise of the Ford flathead, then really picking up steam with the terrific 1955 small-block Chevy to power the ever increasing weight of the longer, lower, wider full-size cars of the late fifties onward. The reliable (but now stodgy) pushrod, inline six didn’t stand a chance except for being the most mundane of people movers in the compact class.
It’s also a very timely article, considering the recent introduction of Stellantis’ new ‘Hurricane’ inline, twin-turbo six replacing the (misnamed) ‘Hemi’ V8. If only the engineers could have found a way to cant the Hurricane six over by 30°. Considering how much mileage they’ve gotten out of the Hemi trademark, it seems like they could have done the same with the nearly as famous Slant-Six moniker.
OTOH, maybe Stellantis’ marketing department figured the introduction of a new slant-six would be associated more with the practical powerplant of the Valiant as opposed to the power and performance racing legacy of the Hemi name.
Who but we few would remember the Valiant or the slant 6?
Inline sixes are cool. Don’t know if it’s ever been done, but I think a Ford 300 six would be a great swap into a early Toyota FJ40 Land Cruiser. Much easier than a SBC swap which is a PITA, I know I did one once for a customer. Even with all the correct aftermarket parts a Chevota (or Toylet) swap is not for the home mechanic. Surely the 300 swap would be easier, replacing one six with another.
Minor correction: Mercury Marine offered the 292 as a Mercruiser stern drive package, the Mercruiser 200, don’t know what years,however. So it wasn’t “just for trucks” 🙂