(first posted 1/24/2016) Pity the poor American inline six. It just never got any real love or attention, unlike the sexier V8s, which were such a cheap way to get a shove in the back. It was perpetually relegated to powering the cheap strippers that thrifty old folks bought because they were done with the cheap thrills, or never wanted any. Or young families who truly couldn’t afford otherwise. Or taxis and fleets. The six had no sex, with only a couple of exceptions.
This blue Aspen wagon has one of them, the 225 Super (slant) Six. Of course, by the late seventies, it wasn’t exactly all that super, due to smog controls. But in its day, it was the only American six that even tried, as all the rest had succumbed to the torpor of the times. And for that, it deserves some love; maybe just the platonic kind, though.
The only American manufacturer that took sixes somewhat seriously in the 50s was AMC. Their compact Rambler was all about economy, and even after their new V8 arrived in 1957, sixes powered the overwhelming majority of them. In addition to the 125 hp base version of their 196.6 CID six, there was also a “power pack” version with a two barrel car packing a mighty 135 hp (gross, in both cases). It was still no hot rod, which would have been totally out of character for a Rambler six. A Rambler six with “scat-back getaway”? Fat chance of that.
After AMC’s excellent new 232 six appeared, it too got a two-barrel version for a few years, through 1967. Power was 155 gross hp, a ten hp bump from the one barrel version. This one got a bit closer to “scat-back getaway”.
(update: AMC went on to develop this six into the most powerful OHV American six, the Jeep 4.0, with up to 190 (net) hp in the HO version (1991 – 2006)).
But Rambler’s two-barrel sixes couldn’t hope to catch this scalding slant six. Chrysler’s new 1960 slant six was decidedly peppier than average, in both the 170 and 225 cubic inch versions, thanks to good breathing from a full 12 port head and long intake runners. They were rated at 101 and 145 hp (gross) respectively.
But Chrysler’s engineers knew the slant six had lots more performance potential than that, and they developed the 170 Hyperpak kit for the 170 inch LG (low block), that included a Carter four barrel carb on an aluminum intake manifold with even longer runners, and a split exhaust manifold. The Hyperpak was only sold as a $400 (expensive) dealer-installed kit, as there were no further internal changes to the little leaning tower of power, which was more than up to a 50% bump in power.
The 170 Hyperpak was rated at 148 (gross) hp, and was specifically designed to make the Valiant unbeatable in NASCAR’s new compact class. It’s generally accepted that it produced somewhat more than that on race day, considering the 130 mph top speed that the Valiants pulled, running at some 6600 rpm. They utterly dominated the series, leaving the Falcons, Larks and Corvairs in their snarling inline six exhaust chorus. (Full story here).
The Hyperpak was designed for racing, the slant six equivalent of Chrysler’s hemi for the big NASCAR cars, although it was quite tractable on the street, and some folks got a kick out of walking away from V8s at street-light drag races with their Valiants.
In 1964, Chevrolet made a very brief, and somewhat odd and half-hearted effort to inject a bit of zip into its 230 cubic inch Turbo Thrift six. Optional in the Chevy II and Chevelle, it was more about the visual, what with its chrome valve cover and air cleaner, than any serious grunt. It got a slightly more aggressive cam, but still kept the one barrel carb and attendant manifolding, the result being a bump from 140 to 155 (gross) hp. Given that the 283 V8 was also available on the Chevy II that year, the timing was odd. Where was this in 1962? By 1965, it was gone again, undoubtedly for lack of interest. More info here.
Pontiac’s SOHC six, based on the Chevrolet 230 and 250 cubic inch engines, was of course the great exception to Detroit’s dismissive attitude to sixes. This was classic John DeLorean, who was perpetually trying to inject genuine Euro-tech into his Pontiacs, like the rear transaxle and independent rear suspension on the 1961-1963 Tempest. His next act in that vein was the 1966 Sprint six, which in four-barrel form packed 207, 215, and ultimately 230 (gross) hp.
His timing was off, as during the mid sixties all anyone seemed to care about was big V8s. They all grabbed the real GTO, not GeeTO, Jr. After three years, the OHC six saga was over, but not before showing those Americans not completely besotted with big inch V8s what a sweet engine a properly set-up inline six could be. And of course, just as Pontiac ditched their OHC six, BMW brought out theirs. In the 80s, Pontiac tried to re-invent themselves as the Walmart BMW, but by then the six cylinder gravy train was long gone.
The inline six seemed destined to wheeze along into the seventies, losing what little power it had to ever more restrictive emission regulations. But Chrysler, that bastion of creative engineering, decided to fight the forces of EPA-entropy, and that the solution was to give the 225 slant six a mild hot-rod going-over.
The result was the 1976 Super Six, with a new intake manifold crowned by a Carter BBD two-barrel carb, a slightly less restrictive exhaust, some careful ignition timing calibration, and a less-restrictive air cleaner. Not exactly heady stuff, but enough to bump rated power from 100 to 110 net hp, and a similar increase in torque from 170 to 180 ft.lb.
Doesn’t sound like much, but an extra ten genuine real net hp in that time of strangled engines was a bit of sunshine, especially for slant six aficionados.
Needless to say, every junked Aspen or Volare with the Super Six long ago gave up its manifolds and carb to every slant six lover looking for an easy bolt on power increase. It’s a well engineered package, and the obvious easy and first step to take in making any slant six livelier.
Ideally, the Super Six would have a proper manual transmission backing it up, like a well-spaced four speed; better yet a fiver. But that was not to be the case; the Super Six, at least in 1979, was only available with the Torqueflite automatic. The one-barrel 225 could also be had with either a floor shifted three speed or four-speed, whose fourth gear was an overdrive. There is no joy in Mudville, which is an apt name for Eugene this wet winter.
I spoke to this car’s elderly owner when I shot it two years ago, and I’m struggling to remember the details. He’s had it for some time, and was a long-time charter member of the slant-six fan club. He favors thrifty, long-live transportation, and this wagon has provided him with many years worth of that.
But now it’s been sitting on the front corner of this large gas station, for a couple of weeks now. I’m guessing it’s changed owners, and the new one likely works here. Well, odds are it will give him some more years of service too. I rather doubt he or she knows that under the hood is the last American inline six that had some aspiration to performance. Super Six? 110 hp? Well, it was the late seventies, and everything is relative.
related:
If cars were bought and owned strictly ‘by the numbers’, the six would have been the endpoint of development. Maximum smoothness and efficiency.
But cars aren’t numbers. Cars are horses. Riding a four-footed beast is in our genes, along with fire and fermentation. We need to feel and hear a gait. Fours and V-8s naturally trot and gallop. A six only has a gait when it needs a tuneup.
a six only has a gait when it needs a tuneup
Well said!
I grew up a gearhead and idolized v8 power, but somehow I ended up with a 1963 Valiant with a 170 ci slant six as my first car. I had it for 7 years and untold miles (since the speedometer cable interfered with my floor shift conversion for the original 3-on-the-tree). My overzealous, shadetree mechanical experiments included a one-to-two barrel carb adapter and a 2v carb from my friend’s 350 Nova—what I would have done for one of these super-six intake manifolds, but they were way too desireable to hang around the junkyard long enough for me to find one. The Rochester 2v carb on that adapter was obviously a study in poor thermodynamic design since the intake manifold inlet size was the same as the old 1v Holley and so this ‘upgrade’ only made mpg go down. I eventually learned to accept the car for what it was and put the Holley back on.
Many adventures and misadventures in that car during my formative years!
In ’70’s, a buddy of mine got his Mom’s ’72-ish Duster with the mighty 225. One day, whilst wandering through a nearby wrecking yard, he spied a slant 6 intake that was, gee, golly, gosh, made of aluminum. Having more holes where the carb was supposed be, he eagerly snapped it up. Later on, said manifold, a livelier cam and a little bit of nitrous were parts of a package that made for a pretty peppy Duster. If memory serves, it eventually was replaced with a brand new ’84 Turbo Laser.
*This* is what most cars were in those days. When these were new, you could see their future, and this was it.
CC effect being what it is, it’s Israeli relative was uploaded on a FB group I’m on (by Gil Cohen), in a similar state too… I’ve no idea whether the dog was guarding it or using it as a territory marking post:)
Thanks for the writeup. I think one of the points of the super six was being able to retain a standard six in the ever heavier B bodies in the seventies where it was standard for a few years in the small Fury/Monaco.
An AMC 2 barrel 258 with a whopping 120 hp was the performance option in Pacers for a few years pre V8.
I think it was a little surprising so many fours in the seventies came with two barrels, although the Lima dropped back to 1 barrel with the fox body and the iron duke arguably when it went single point TBI in 1982.
The Chevy 250 inline 6 perhaps deserves an honorable mention in actually creaping up from 100 hp net in 1974 to 115hp in 1979.
The Lima “dropped back” to a 1 barrel BEFORE the Fox-bodied cars appeared. Someone will probably correct me, but if they even had a 2 barrel it was gone by 1976. I owned a 76 Pinto, and I could be wrong, but I’m reasonably certain it had a 1 barrel.
A friend of mine had a ’76 Pinto Pony MPG, the plainest model they made, and it had a Holley/Weber 2bbl on it.
It took a little digging and I have to admit you are correct. The 76 Pintos used a Holley-Weber 2 barrel, while later Pintos used a Motorcraft 2 barrel. Maybe I was thinking of the 6 cylinder used in Fox-bodied cars?
It is interesting that Ford was not claiming any horsepower advantage in the 79-80 Pinto due to the 2 barrel versus the 1 barrel 2.3 lima in the fox Mustang. I assume there was one but having the lighter Pinto be faster than a base Mustang is not something Ford would mention. I suspect a 2.0 or later 2.3 would always have been faster than the big 71-73 Mustang with the 200 6 or the Pinto based but heavier Mustang II, at least the 4 speeds.
It was getting late last night when I put this up, and I forgot about the Pacer’s 258 two barrel. I knew I was forgetting something…
1960 was years before I got really into cars, up to that time cars were just “metal boxes” with fancy sculpting as far as I was concerned. But since I would be a Falcon, and then a Valiant fan in the late 60s-early 70s, I wish I had been able to see those NASCAR compact class cars racing.
I’m also a Volare fan (the Aspen? not so much), I guess I’m a sucker for that faux Mercedes grille.
What a combo that Super Six and a floor shifted manual transmission would be….especially as a wagon.
One thing I remember when I had a ’76 Aspen wagon with the 225 slant was how easy it was to work on. Additionally, it seemed like a never ending work horse. Yes, it was weak, particularly when I towed a small camper trailer up hills, but it never quit. Sure I had to do 40-45 mph up the right lane on the interstate, but I knew that it would get me to my destination and home again.
I’d say a postscript to this write up would be the Vortec 4200 Atlas DOHC straight six that GM produced from 2002 to 2009. It was 4.2l and made 270 hp/275 lb·ft in its initial form and 291 hp/277 lb·ft in its final form. I was quite sad when GM terminated production of its Atlas series of engines without using them in anything other than SUVs and trucks (barring the odd concept car). I’m still tempted to pick one up and use it in some sort of custom creation.
Ideal swap for an early Nova? Should make it wake up and go quite well…
The Atlas was plagued by poor quality control in its injection molded head. They were cracking all the time, and the warranty rates were high. At the time, most buyers went for the 5.3 V-8 anyway.
Buyers of what? The only vehicles those engines were offered in concurrently were the GMT 360 quintet, and the overwhelming majority of them had the 4.2.
Atlas inline 6 engines and the 5.4 V8 were available in the first generation Colorado pickup and the Hummer H3.
Oops! 5.3 V8. ;
Been having problems with injection molding or casting of aluminum every since it was first invented in the late 50’s. GM and AMC paid the price of this folly in the early 60’s. When Rover bought the GM 215 aluminum V8 the first thing they did is throw away injection casting and went back to sand casting. They only got another 50 years out an engine that GM only got 3 years out of.
That was a helluva motor too.
The Buick 215 was sold to the Brits because it was considered to small for the american Buicks.
I had one of those in a Rover, the engine was great, everything else well not so much!
It’s a too bad they didn’t offer the 4 speed with the Super Six, that could have been a fun little car. The 2 barrel really woke the six up and the ratios on the 3 speed sticks were too wide for any performance driving.
For several years I was looking for a Volare/Aspen wagon for a daily driver but not being a six cylinder fan, my caveat was it had to have a V8. I looked at maybe a dozen cars but they all had sixes and most of them were Supers, although I did see one Aspen with a 318 but it was out of my price range and really too nice to drive everyday. I finally found an 80k mile 79 Volare wagon with a 318 last year that was exactly what I was looking for. So, while the survival rates for these cars are pretty low, the ones that did survive seemed to have done so buzzing along with /6s.
Nice find, typical no-nonsense wagon from the days that a wagon was not used to show the world you hauled golf clubs around. Or a long haired dog as big and heavy as a Shetland pony.
Bakers, plumbers, electricians, house painters etc. drove them back then. Family car + commercial vehicle. Below a contemporary GM product.
Ah, but that was also available with Opel’s big six as the Commodore:)
Those were specially built for all kinds of rush jobs.
For the owner of a furniture company or similar…
Big slant 6 fan here. I’ve owned a few and loved them. They always seemed “just right” in so many ways. Economical, powerful enough and easy to work on. I still miss that sewing machine sound that they made.
Great writeup. I owned a 67 Rambler American with the 2bbl and it was no slouch. AMC did a great job in designing the head for those as the porting was far superior to anything Ford or GM had. They wanted to compete with the small V8 cars of the time and still come across as economical. That motor lived on almost to the end of the century in Jeeps. And speaking of Jeep, no mention of the OHC Tornado? Or maybe the less than stellar Studebaker 170 OHV ?
And the OHC Tornado got a 2nd life in Argentina when the Rambler American became the IKA (Renault) Torino. https://www.curbsideclassic.com/curbside-classics-american/cohort-classic-1971-ika-torino-ts-the-legendary-rambler-south-american/
It was getting late last night, and I couldn’t really do a comprehensive look at all the sixes, so I stuck to passenger cars. I did cover the Tornado recently in the Torino post. But IIRC, the Tornado as used in US Jeeps only had a one barrel carb (I could be wrong), which seems a bit odd. But then it was really about making more torque in that application.
The pre-emissions 232 AMC six was a good performer, and was a real change from the 1930s-era sixes (L-head and OHV conversion) used in the earlier Ramblers. Early on AMC advertised it as “the six that comes on like an eight.”
There was the ultimate performance version of the AMC six, the 173 net hp version found in 1987 Jeeps. It was quickly bumped to 177 hp then 190 hp. For the ’90’s. Its a bigger bore and shorter stroke than the 258 cid six, so it revs more willingly, but still with excellent torque.
When combined with a 5 spd, its a nice package. Too bad it came along far too late to wake up a lightweight AMC compact.
Quite true. I was sticking to passenger cars, and sadly the 4.0 was never offered in one.
Someone here in northeastern Florida transplanted a 4 liter and 5 speed transmission into a lare 60s Rebel station wagon. If I remember the Craigslist ad the seller wanted about 5 or 6 grand for this car.
I wonder what could had happened if Chrysler had bring the Australian Hemi-6 in North America? Just imagine the Dart/Valiant/Duster, Aspen/Volare, Coronet/Satellite, Monaco/Fury, Diplomat/Gran Fury with an Hemi-6 under the hood?
Yes our local Hemi sixes were powerful, but they didn’t have the smoothness of the Slant Six, and not quite as long lived.
They used to get timing chain rattle and valve clatter quite early on.
I have never owned a Chrysler product with the slant six, but I have had a few AMCs with the 258 six and I thought they were pretty good power plants, smooth, torquey and easy to work on. Maybe not as much horsepower as the 225 but I wasn’t really too interested in that anyways.
I actually like the American inline six engine. V8s are fine for pickup trucks or if you need more pulling power and torque. But for cars, for light duty trucks, an inline six can be just as good an engine. Why it was never as liked, or as respected, as the V8 engine was is beyond my thinking.
It’s called marketing. The marketing people convinced the majority that they needed a V-8. They are still at it but push different must haves nowadays.
Inline six is really a long configuration, and it limits the space efficiency in a vehicle smaller than a typical full size. And parts sharing from inline six is worse than L4, V6 and V8. There are so many reasons not to manufacturing L-6 for affordable cars after downsize.
FWD was the true main in the coffin for inline sixes in cars, there’s very few examples in history I can think of with a transverse I6. Virtually any rear driver can house one, the fox body being probably the latest example(despite using V6s in it’s final sn95 years). Given RWD has become exclusive only to niche platforms and utilitarian vehicles like trucks the transverse V6s just make due in them.
Inline eight with transverse mounting didn’t turn out right on tempo neither. http://www.drivingenthusiast.net/sec-ford/FMC-engines/t-drive/default.htm
Transverse-mounted I8 in a FWD car? *Nods approvingly*
BL had I6 Land Crabs & Princess wedges. There were some even worse Australian models. Land Crabs sold well (for some reason) in the UK, it was the sort of car you hoped your parents never bought!
Daewoo/Suzuki had a transverse-mounted inline 6 for a while. It was sold in the U.S. as a Suzuki Verona.
Volvo S80 as well I6, FWD
Yes S80 T6 was a fast car!!! I worked at Volvo late 90s early 2000s and that car was wicked fast!!
Perhaps honorable mention should go to the large displacement I6 VAM (AMC Mexico) whipped up South of the border. Supposedly those 4.6 liter units put down serious power.
Today there are people installing the long-stroke crank from the AMC 258 into Jeep 4.0 motors which makes for about 4.6 liters. Power varies depending on the build, but I’ve seen numbers like 270 hp and 320 ft-lb of torque.
That’s a nice sized little wagon, and the” super six” just seals the deal. The slant six was the only American six that was designed with decent breathing, even without a cross flow head. I drove my Dad’s ’60 Dodge Seneca with three on the tree and it was interesting. He also had a ’55 Chevy sedan with six/Powerglide and it was okay, pretty smooth but slow. I’m still driving my ’70 Mustang with the 250 six/ automatic and it’s been pretty good. I’ve decided to accept my Mustang for what it is and I appreciate it in many ways. Performance is adequate. It’s got enough torque to move off the line smartly and it climbs hills really well. I came up the Cuesta grade outside Paso Robles at a steady 65 mph, keeping pace with a ’69 Camaro SS that was going the same way. I’ve had it up to a calibrated 90mph. with a little left, and it will cruise at 70mph. with no problem. Well the only problem is poor gas mileage.
It’s unfortunate that the American car manufacturers didn’t put as much development into the six in the Sixties. In the Fifties, before the small block Chevy arrived the GMC “big six” was the GM performance favorite. Chrysler and AMC were still in the game but Henry Ford had always hated sixes and I guess his legacy lived on. In many ways the “Falcon light six” is a pretty good motor. Though it started as a 140 cid. five main bearing motor it gained two more main bearings when it was increased to 170 cid. Probably the best all round displacement is the 200 cid, it seems to be the best breathing, even with that awful integral intake manifold. I think the 250 cid. is just too much displacement for the available manifold. My guess is that it is set up to run pretty rich at higher rpms. to keep enough fuel going to the cylinders with that awful manifold. The different displacement versions pretty much all weigh the same, even the 250 is only 10-15 lbs. more. These all are much lighter than a small block Ford, which is pretty light. I think some of the other manufacturers’ sixes were as heavy as their small block V8s.
Nowadays these six cylinder cars are kind of distinctive, especially in a pony car,or intermediate model. They are also much cheaper and are a great way to get into a classic ponycar. An early Barracuda with a super six would be great.
And Ford Australia continued to improve the I6 engine for their Falcon even gived it a turbocharged and a OHC version. http://classicinlines.com/history.asp
You can have it. I despise these wretched Ford sixes, my moms ’66 Mustang had one of these boat anchors.
They to a one sounded like, and ran like crap.
Every time I turned the key on that thing, my face would scowl up at the thought of it, why couldn’t it be a 289?
The old man thought it would be economical, ha ha! The six chassis components were so flimsy compared to the V8, that several years worth of front suspension repairs, brake jobs on the go-kart sized brakes and fixing the broken rear end
(ring gear about the diameter of my fist) would have more than covered the marginal MPG advantage of the 6.
The only good thing about a six Mustang is as a body donor for a V8 conversion, no simple task as to do so, everything goes but the body shell.
I remember these in Air Force blue as staff cars. All slant sixs except for the SP patrol cars which had the 315 V8 which used to get drag raced up to the Elephant Cage radio mast at RAF Chicksands.HAPPY DAYS.
I remember reading about the Super Six in the brochures. The slanty had been pretty strong in the early 70s but was starting to wheeze as the tightening emission controls took over.
I read somewhere that there was a big difference in the torque characteristics of the 170 vs. the 225. The 170 liked to rev while the 225 was a down low torquer. I never drove a 170, but my 225 fit that description.
I’ve never understood why govt. feels they have to force car makers to employ devices that sacrifice performance. I want to breathe clean air as much as most people, but this is bullshit. Not at the expense of sacrificing performance or reliability. That’s never made sense.
They didn’t, no dictate specifically required the junk bandaid solutions the automakers came up with, they just required they comply to a new standard and this was the automakers response. I hate intrusive and unrealistic regulation as much as the next guy but it is possible to have a clean burning engine that makes power and is efficient, today is proof of that.
It seems like a rather un-realistic standard to meet. It’s as if they’re trying to eliminate every little molecule they deem unhealthy from the tailpipe of a vehicle.
Bear in mind that the sophisticated microprocessor technology that makes it possible for today’s engines to be both clean and powerful did not exist in the 1970s. Today’s typical car has more computing power than a multi-million dollar supercomputer center did 40 years ago.
Take a pre smog engine with a draft tube. Add a PCV valve and a closed crankcase system and you have eliminated 75% of the emissions of the pre smog engine. So for the last 50 years and hundreds of billions of dollars we have been trying to eliminate the last 25% of emissions when it only cost at the most $0.00 per car and one year to eliminate the first 75%. The law of diminishing returns in action. People never know how to quit when they are ahead.
Well that is the idea. The regulations were idyllic for the era but ultimately possible. The truly engine choking period was before catalytic converters, and right after the elimination of leaded gas, once cats showed up power began to rise again, well before EFI.
You guys need to go spend some time in a place like Beijing or Mumbai. I have, and I have experienced, first hand, what a place is like without emission controls. Must of the coasts of the USA would be just like these wonderful places if it weren’t for the EPA.
Go live in Beijing for one year. Then come back and tell me you don’t want controls on pollution.
Me? Yeesh I’m the one actually defending the regs for once in this thread and I still get condescended to by the “enlightened”.
Really starting to think the tagline of this site should be changed to “Curbside Classic: Why old cars deserve to be kicked to the curb”, that’s pretty much been the prevailing attitude around here lately.
Beijing is the example about how emission control doesn’t work. When people in Beijing drive alarming rate of brand new European/Japanese/US/Korean/French/Chinese cars with the latest emission control systems complying almost latest emission standard ( annually emission test is pretty harsh on older cars as they wouldn’t grandfather those complying older standards ), that’s the air returned. While people in the US, especially in many areas with higher concentration of older cars the air is still far cleaner, despite much pollution from pre-smog cars/carb cars.
But a big crowd of brand new cars still pollutes a lot when idling driving, and few older cars are more environmentally friendly if driven at a reasonable speed with reasonable maintenance.
orengechallenger: Like many things, it’s not nearly as simple as that. There are many factor’s in Beijing’s air pollution problems, including its weather and its proximity to dusty areas to the west of it. Something like 30 million or more live in the city as well as the areas surrounding it. Almost all of its electricity comes from coal-fired plants. And there are still lots of older dirty diesel trucks and industrial equipment.
In modern cars, it doesn’t matter whether the car is idling or not; emissions are very low at any operating speed.
Even with improved emissions on newer cars and trucks, there are simply too many sources of pollution when the air is stagnant there to keep from becoming very ugly.
” Really starting to think the tagline of this site should be changed to “Curbside Classic: Why old cars deserve to be kicked to the curb”, that’s pretty much been the prevailing attitude around here lately.”
It’s just kids Matt , no worries .
Even back in the 1950’s , 60’s and 70’s many shops didn’t have a dwell tachometer nor timing light , or like the Dealers , no one bothered to use them so those fine old InLine 6 cylinder engines rarely were even close to being properly tuned .
Some , like the tiny Ford and 170 ChryCo sixes , were simply too small but most had at the very least adequate power *if* they were maintained in sharp tune , most had solid lifters that were never , _ever_ adjusted and this too reduced power and made for hard starting when the gaps closed up .
-Nate
I’ve never understood why govt. feels they have to force car makers to employ devices that sacrifice performance.
The don’t. Cars have more performance and power than ever.
Yes, in the 70s and early 80s, it was a bit of challenge, and US carmakers were too cheap to use fuel injection. Porsche’s engines never went down in power during the Malaise Era? I wonder why?
Anyway, that’s all a long time ago. It’s a bit late to get upset over that now.
It was not only the americans who lost power. A lot of the European cars that was sold in the states had lower HP rating than in Europe. In Norway we didn’t use unleaded fuel before in the late 80s, and new american cars got the cathalytic converter removed before they got registered.
The character, Sonny, on the HBO series “Treme” drives a little blue Mopar wagon like this one. I’m a 90’s baby who grew up with Japanese imports. but I am a relatively new Slant Six convert. I have had an 85 Ram Wagon(Van) with a 225 and 4 speed 833OD for about a year and a half. Rusty but trusty, she has been a very reliable and tough old truck. It was a bit of a smoky dog when I first bought it; but new plugs, wires, fluids and timing chain\sprocket set really woke the old slant up and eliminated the blue cold start smoke. I installed a class IV hitch, freshened up the brakes, and it has towed anything I’ve hitched it to. This includes a Maxima, Civic, and a late 80’s Olds B Body Sedan on a tow dolly. Also a tandem axle uhaul while loaded to the gills last time I moved. It wasn’t fast, but it didn’t seem to mind much, and as another poster stated, it never quit. I wonder if it ever towed before I picked it up, it had no hitch, but with the 3.90 rear end, it won’t go much over 65-70mph. At 31 years old I have driven it as far north as the MN\ND\Canada border and as far south as Nashville, TN.
I have heard many say that the Slant 6 will outlast the body it lives in. My van is a little rusty, but not bad for a Michigan\Chicago native. If I came across a clean old Maxi-Van, and the price were right, I think It’d be neat to swap my van’s drivetrain into a larger cleaner van body.
I remember the ’79 Aspen my parents bought brand new. It was loaded with just about everything you could get, but had the 225 slant 6. The Super Six was not offered in California.
Before that they had a total stripper ’74 Duster with the 225, and that lightweight car ran quite strong. But the California emission strangled ’79 struggled to move, and got even worse with the AC running. It should have been ordered with the 318.
Also had a ’75 225 slant 6 Dodge cargo no side window van with automatic, it actually ran pretty strong, at least when it was empty. Almost as strong as a friends ’77 Dodge cargo van but with 318. But after the ’75 got about 40k miles on it, the power really seemed to go away. The ’77 didn’t seem to lose power as time went on.
The 225 really got neutered badly with ’75 and later California smog equipment.
6 maniac here! Had 3 inline 6s, my first American car a 64 Mercury Comet 4 door, a 69 Javelin & a 70 Vauxhall Cresta PC (often mistaken for a RHD American car). More secretary’s specials please
There are quite few things on this ’79 Aspen. It has the egg crate grill from the Volare, and for such a base wagon ( vinyl seats, no wood trim, now wood trim at all inside ) it has rear window defrost and delay wiper, and I saw the tip of mirror on the right. But I never saw that kind of mirror on F-Body though, even as late as 1980 it was still round like ’76. And the owner even kept the fuel cap with lock.
I have owned straight sixes from Studebaker, Ford, Chev, and AMC. I have had a blast with them (driving slow cars fast). The fastest one I have personal experience with was a 55 chev owned by a guy I was stationed with. Had a 2 carb manifold, headers, and I think a cam. All from JCWhitney. A four door with the rear handles removed and glassed. Surprised a batch of V8s and that was fun to watch.
Wanted to have a slant six but it never was convenient. One of my servicemen bought a reclamation from the phone company that seemed to serve pretty well.
Almost played some games with the Datsun straight six from the 240/260Z cars but common sense prevailed.
I’ve never driven an inline six car I didn’t like, partially because I’m always pleasantly surprised as a die hard V8 guy. Really my allegiance to the V8 is all about noise these days, can’t be matched, but the inline 6 is my favorite engine design as a design. No angle compromises or rudimentary band aids like balance shafts or counterweights, they’re incredibly simple to work on for the biggest and littlest tasks, look great under the hood, and run so silky smooth. A true automotive example of the KISS principal, whereas the V6 is the work of satan as far as I’m concerned, sure they’ve had the many many bugs camouflaged by massive engineering budgets and decades of time but what miserable architecture to spend those resources on.
I bought my grandparents slant-six, 1980 Volare, when they were done with it in 1993. I promptly did the super six upgrade, including the 2.25 inch exhaust. Really perked up the car. Trap speed at the drag strip went from 67 mph to 70.
A few years ago I noticed a clean 1967 Pontiac Tempest hardtop coupe in a supermarket parking lot. Turned out it was equipped with the SOHC six. I spoke with the owner, and he had restored the car himself, as he knew exactly what he had. It’s too bad that Pontiac didn’t continue developing this engine, instead of abandoning it after only three years.
As for the Aspen (and Volare), it seemed as though the overwhelming majority of the coupes and sedans had the six, as those body styles initially appealed to Dodge Dart and Plymouth Valiant/Duster loyalists, while most of the V-8s went into the wagons. It would be interesting to see the actual production figures for sixes and V-8s in these cars.
In Popular Mechanics archives, you can find the take rate of six/V8. It’s alarming low, the last time I read it, it was less than 15% V8.
By compare, the V8 F-Body is more common today than when they were new.
Hate to be pedantic, but it was actually 4 years, 1966-69.
Interesting write-up. Great CC of the Aspen wagon, and nice images of other 6’s too (that bring up a lot of thoughts). A lot of interesting comments. Always liked 6 cylinder engines of all types, and the in-line configuration is hard to beat for it’s inherent smoothness. The seemingly indestructible Chrysler slant 6 would have to be one of the best examples. Interesting what appears might be an open road draft crankcase ventilation tube on the Rambler 6 (probably common for the times), and pretty sure that nice looking Pontiac OHC 6 had a belt driven camshaft. Times have certainly changed. A draft tube like that would be replaced today by a much cleaner PCV system, and belt driven camshafts are now common.
My Dad and I went in on a bespoke ’76 Aspen coupe with all the geegaws. Our options list went for as much luxury as possible, hosted by the most economical drive train. Two-tone silver and black ( with nifty black window surrounds) and red pinstripes, sunroof, mag-style wheels, maroon interior with (get ready for it) white vinyl 60/40 seating, folding rear seat with a chrome bump rail over a carpeted back (like a first generation Barracuda) and a full-width pass through to the trunk. Very sharp looking. The bad part was the drive train. We were accustomed to Mom’s ’73 Scamp, which had plenty of power. The Aspen was a super slug, totally overwhelming its strangled slant six. We opted for the 833 4-speed manual, on which the top gear was an overdrive. This should have been peppy and economical, but was a total failure. Not only was it slow, but the trans couldn’t make any decent fuel economy, either. We judged the Aspen/Volare as inferior to their predecessors. I ceded my ownership half to Dad and bought myself a 9-year old Chrysler 300. He traded the Aspen in on a Chrysler LeBaron sporting a 318, in the body that became beloved of many a police department in Plymouth guise. Too bad, because the Aspen went on to become a decent car. But it sucked in ’76.
Hi Paul, the Tornado powered Wagoneer was available in the U.S. with a 2bbl. I owned one for a while, but sadly never got it on the road to get more familiar with it.
This article is talking my language. I like big straight six motors.
What you want for durability is a motor with a large bore, a short stroke, lots of main bearings, large diameter main journals and rod journals, very LOOOONG connecting rods, deep piston skirts, and tuned for low RPM torque. Inline sixes are inherently superior to V8 motors for vibration reasons but inferior to V8s for weight and packaging efficiency and high RPM breathing. Internal vibrations in an engine accelerate wear and tear on the crankshaft and the bearings and sixes are superior to V-type engine and semi trucks are always inline sixes. Long strokes and short rods accelerate wear on the cylinder walls and piston rings but are attractive for packaging efficiency and weight savings..
There are a few engines out there that stand out a long ways when you start comparing internal dimensions such as bore/stroke ratios, rodlength/stroke ratios, piston skirts, number and size of the main bearings, etc and they almost always are inline sixes.
V type motors tend to have thinner rods and narrower rod bearings because they put two rods on one crank throw. This is undesirable for durability.
theoretically the perfect gasoline six for a large car/truck has a 4″ minimum bore, a 3″ max stroke, minimum 7″ long conrods, 7 main bearings and a massive crankshaft, large diameter journals and very wide bearing surfaces and lots of counter weights. This engine does not exist as far as I know but some come close in terms of ratios.
anyway, some engines that stand out in my opinion are:
GMC 248 inline six
AMC 199 inline six
Ford 240 inline six
Mopar 198 slant six
Nice, one of the advantages of the leaning tower of power is room for a nice swoopy intake manifold.
The ones on AMC sixes were so blocky they looked like they were made out of Lego.
Thanx for the i6 thread Paul ! .
You know I love ’em .
I’ve never had a ChryCo Super Six but would like to try one .
Those doggy 1970’s through 1980’s i6’s are fairly easy to wake up with proper ignition advance tuning and EGR valve deletion or tweaking so they never open below 2,500 RPM’s .
-Nate
I believe that the Chrysler slant six was actually an adaptation of the 1930’s flathead six they were using until 1960. They needed an engine to fit in the Valiant and something more modern and not wanting to spend much money like Ford did with completely modern precision cast 6’s for the Falcon, they put overhead valves on the old engine and the tilt was because it was an old long stroke engine and particularly with the added OHV it had to be tipped to clear the Valiant hood, as well as the hoods of the lower full sized cars cars of the time. Engine height was hardly an issue when the original engine came out in the 1930’s.
Could be wrong. Probably Wikipedia knows…..
The slant six was a totally new engine, specifically designed for the the Valiant. It was the 170 inch version that was designed for it, and it does not have a long stroke.
It dawned on Chrysler that they really needed a new six for the big cars, so the easy solution was to raise the deck and add an inch of stroke. That’s how the 225 came to be.
There’s nothing really wrong with long stroke engines; practically every Honda four of the last 30 years or so is a long stroker, and they can rev to 7000+ rpm, yet make decent torque.
In fact, most modern engines have gone back to being relatively long stroke; turns out it helps them run cleaner. the short-stroke era is long over.
” the short-stroke era is long over.”
ah, no
racing engines still use short strokes
They’ve come a long way with modern metal alloys, coatings, lubricants, and out-of-this-world dimensionally precise parts and ridiculously close tolerances. But they still cannot overcome basic laws of physics. The incessant quest for more power from a smaller engine with higher compression and a longer service life will eventually bring back the short stroke to production cars. You can write that down.
I wasn’t talking about racing engines, which are increasingly irrelevant to what’s happening in production engines.
“The incessant quest” will be for ever-greater efficiency, and the long stroke engine is clearly at an advantage in that regard. The use of psuedo-Atkinson cycle engines is spreading, and they do not function well with short strokes. And as forced induction continues to spread with smaller engines, that too favors longer-stroke designs.
“Longer service life”? Are you kidding? Modern long stroke Honda and Toyota engines have greatly expanded the predicted service life of car engines. There’s no correlation anymore. You’re stuck either in the 60s, or in certain theoretical notions that were formulated back then that don’t apply,
A long-stroke Civic engine does it all: rev high, good low end torque, good efficiency, and long life.
There will not be a movement back to very short stroke engines. And you don’t need to write that down. It’s already self evident all around you. Unless you think you know more than all of the best engine designers in the industry. That wouldn’t surprise me. 🙂
Sometime around 1978, GM came out with a somewhat higher performance 4.1L (250) straight 6 for full size pickups and vans. The engine used a staged 2 barrel Rochester carburetor that was basically half a Quadrajet 4bbl. (split lengthwise), had an intake manifold integrally cast with the cylinder head, a low restriction exhaust system and a clever air injection (emission) system that didn’t use a belt-driven air pump. I think it was probably more of a case of holding on to whatever horsepower the 250 had in the face of tightening emission control regulations than actually offering a high performance 6 cylinder. The 2bbl. 250 was adequate for a 1/2 ton truck and it lasted until 1985 when it was replaced by the 4.3L V-6.
Those engines cracked cylinder heads like crazy ~ at one point I had 10 or 15 1/2 ton pickups sitting ’round waiting for GM to release the new design , crack resistant cylinder head….
The A.I.R. system , I’ve forgotten , was it a pulse typ ? .
-Nate
Yes, it was a pulse-air system. And now that you mention it, I do remember issues with cracked heads early on. I never saw many of these, even during the second fuel crisis most opted for the 350.
I’d never heard of this, but a check of the brochure (1979) shows it.
They used a similar carb on early 1980-81 Iron Duke FWD X-bodies.
I had one of the POS and the carb did look as you describe.
I’d forgotten about that. And I agree with your assessment.
I like the shape of these as wagons. Crisp and well proportioned. Enjoyed a 225 in my 64 Valiant wagon. No problems with power but I’ve never really driven a V8. MF to start on cold winter mornings though.
Six fan here also. All 7 of my Mavericks are sixes. And my 87 F150 had the FI 300 with granny four. That one I miss.
The slant six (and all inline sixes for that matter) cries out for a decent fuel injection setup to replace the carb. I grant that the long runner intake manifold looks good but, typically, what happens is that cylinders 3 & 4 tend to run too rich, numbers 1 & 6 run too lean, while 2 & 5 are fairly close to optimum. A multiple carb setup would help but if it were up to me, some sort of EFI set up would be installed. One of my recurring fantasies is building up a slanty with fuel injection and a tuned exhaust, installing same into a sixties Valiant/Dart along with a 5 or 6 speed manual, upgrading the brakes and suspension, and then go looking for V8’s to embarrass.
I agree. My favourite is the 225 slant six used on most Mopar compact cars, the Dodge Dart, and the Plymouth Valiant/Duster.
Agreed. Like Maxwell Smart, the I-6 (particularly the slant-six) missed the EFI era “by that much”. Just imagine if the /6 had gotten a decent EFI system. It probably still would have been discontinued, but at least it might have gone out with a bang.
It’s worth noting that the popular turbocharged diesel engine in Ram pickups has been an I-6 since its 1989 introduction (although it’s made by Cummins). The diesels in Ford and Chevy pickups are NA V8s.
My high school friend inherited a 1979 Volare’ sedan with the Super Six and it had just over 100K miles. For some reason never explained to this day it was a total dog out of the hole. If you stuck banana peels and oil under the tire it wouldn’t and couldn’t spin a tire to save it’s life. it was even worse with the A/C going and 3-4 passengers. He changed out literally everything including plugs, wires, rotor, cap, carburetor, seals, torque converter (which had the then new mechanical lockup feature) and still it was a total dog. He took it to several garages that specialized in Mopars and even they were baffled. Timing this car from 0-60 took an exhausting 16 seconds if I remember correctly making that car slower than any 1BBL ever thought of being. In fact his 1974 Scamp with said 1BBL 225 would run circles around this car. Since the Super Six was such a rare site by the 90’s we never did get the chance to compare another Super six.
We did race it with one of our trade in cars, a 1979 Pontiac Lemans sedan with the re-worked 231 Buick V6 and 115 HP and 60K little old lady miles. It blew right past his Super six by about 4 car lengths which shocked both of us as the 3.8 never felt that quick in most cars we drove. We never to this day have been able to figure that one out.
My aunt had a 1977 Dodge Aspen SE two door for several years. It was an awesome car, quite reliable.
My experience with inline sixes was confined to two cars. The first was a 66 Mustang, 200CID with that awful non-synchro three speed tranny. You could drive that thing all week on a tank of gas, something my 351W 69 Cougar could not do, but it was slow. I loved the smoothness of the six and wished it had been mated to a four speed. Back in those days, the late 70s, my pockets weren’t deep so the only thing it got were some new freeze plugs.
My other six was a 95 Volvo 960, which used their new inline 6 as their hideous French V6 had been an absolute disaster. It was smooth and powerful, but it sucked gas far beyond what it should. It was a tough engine, when the car and I parted company it was at about 150K and it never missed a beat.
I was looking at 4.0 powered Cherokees in the late 90s, but instead opted for a 318 equipped Durango instead. I really liked that 4.0 six.
Through 1993 to 1995 or so, we had a pretty beat up yellow 1980 Aspen station wagon, when I was growing up. I was pretty embarrassed by it at the time (no hubcaps, plus it was pretty rusty and the paint was pretty faded), but it was the most reliable transportation you could hope to have. I miss it, because it had character. I remember the vinyl bench seats being terrible in both winter and summer…..the best of neither worlds. I believe that the windows even had remnants of those plastic stick on windows that wouldn’t fog up or need to be scraped of frost in the winter (anyone remember those?).
But damned if that Slant Six wasn’t still running strong. Same thing with our beat up 71 or 72 Dodge Tradesman van, that was a survivor from the shaggin’ wagon days, with some remnants of shag carpeting on the doors. The tranny eventually lost it’s reverse function, but the engine itself was still going strong. I honestly don’t know what it would take to kill those engines, because we also live in Winnipeg, which see -30 to -40 winters, and that craptastic Tradesman van just would not die (engine-wise).
That’s what I’ve always liked about Mopars of the 70s. What they may have lacked in the sexy dept, and personality, they made up for in durability and reliability, all things considered. Their engines would continue long after the car bodies would rust to dust. 🙂
I briefly had a 1969 Mustang with a 250 cid engine. Unfortunately by the time I had gotten it, the old 250 was out along with its manual transmission and changed to an automatic with a 1978 250 in its place.
The 250 was a torquey engine and certainly was not underpowered – it would pull and get out its own way. I would have loved to have experienced it in its original manual transmission life (one day I was working on the car and discovered the clutch pedal was still there tied down under the carpet).
I love straight sixes except for that dreadful slant six garbage hauler from MOPAR.
I own a 1979 Dodge Aspen. witn a 225 super six. I have rebuilt the engine . I am now having a problem putting on the power steering pump brackets. I would like to drive my car again.
I’ve had a six myself last year. A black 1974 Chevelle Malibu with the 250 and a 3 on the tree. I previously had a red 1979 Fairmont Futura coupe with a white vinyl roof and a four speed behind a Lima 2.3 inline 4, I traded it for the Chevelle. As can be expected it was just as slow as the Fairmont but it sounded a lot better, it was a comfortable car with plenty of torque though. Cool car to have as a 20 year old kid in Europe, it was converted to run on propane (way cheaper than gasoline) but sadly the propane system was very unreliable and the wiring was a mess. Ladies liked it and my friends loved riding along in my ‘mafia car’, but in the end I’m glad I sold it. I do miss the Fairmont, I’ve heard its back in the area though so I’ll likely see it again sometime soon.
Folks above say that the I-6 died due to the switch to transverse FWD, and that’s partly true. But in RWD applications, I believe both GM and Chrysler switched (in the mid-80s) to 90-degree V-6 engines because they could be produced on V-8 production lines, whereas a straight 6 needed its own line.
Chrysler lopped 2 cylinders off the 318/5.2 to create the 3.9 V-6. Allpar says it was created because the Dakota couldn’t fit the Slant 6, and since they were making 3.9s anyhow, it made sense to shut down that line and put the 3.9 in f/s trucks and vans as well.
Same story at Chevy, basically. The 90-degree V-6 started off in the A/G and B-bodies and by the mid-80s it found its way into S-trucks and f/s trucks and vans. It just didn’t make sense to produce the I-6 just for trucks, so base trucks got the 4.3 also.
I know this post is all about the slant 6, but I just can’t stop looking at that sad interior shot, which reminds me of a low-end Volare I had to ride around in occasionally as a kid. Really, did Chrysler not give you dashboard air vents in 1979 unless you ordered A/C? I know GM and Ford only gave you two instead of four if you didn’t order air, but giving you zero is seriously cheap. I don’t see the cowl air ducts that Mopars of a decade earlier had either, so I guess it’s just the defroster or heater ducts for fresh air ventilation, or roll down the windows. Then there’s that vinyl seat material, which looked and felt more like a cheap rubber floor mat than anything appropriate for automotive seat upholstery. It seemed designed to trap as much dirt in the crevices as possible. At least it seemed durable, a good thing for a car with a slant six & Torqueflite.
The F-bodies without air didn’t have panel ducts, but they did have under-dash vents. Not the twiddle-the-latch-and-open-the-door kind found on the Dart and Valiant; they had pull knobs under the dash (like the ’60-’62 Valiant-Lancer) to open the left and right vents.
The engine was/is a workhorse. In this ride, it would provide no power to speak of.