Introduced in 1962, the 90-degree Buick Fireball V-6 engine was basically three-fourths of Buick’s small aluminum V-8, cast in iron rather than in light alloy to create a cheaper base engine for the compact Buick Special. Although this 90-degree V-6 went on to a very long career (used on new vehicles through 2008!), the early “odd-fire” versions had a peculiar sound and a coarse feel created by its unusual firing intervals. Let’s take a look at why Buick originally chose this design and what happened when they went to a smoother “even-fire” crankshaft in late 1977.
Buick Odd-Fire V-6
Paul previously posted an engineering analysis of the V-6 from the November 1961 Car Life, which describes the design rationale and features of the early Buick Fireball V-6. Rather than recap that, I’m going to focus specifically on the ramifications of the uneven firing intervals.
The original Buick “Fireball V-6
With reciprocating piston engines, certain engine configurations have an intrinsic tendency to shake due to the unbalanced forces and couples caused by the motion of the pistons and connecting rods. In a 90-degree V-6 engine, this includes both a primary imbalance (that is, a vibration occurring at engine speed) and a secondary imbalance (occurring at twice engine speed). This imbalance isn’t a matter of bad design versus good — it’s inherent to the engine layout, a function of the motion of the reciprocating masses relative to each other.
The crankshaft had three throws, spaced 120 degrees apart / General Motors LLC
Until late in the 1977 model year, the Buick V-6 also had another unusual characteristic: uneven firing intervals. Unlike an inline-6, or the 60-degree V-6 engines common in more recent years, where one cylinder fires every 120 degrees of crankshaft rotation, the early Buick “odd-fire” V-6 fired at uneven intervals of 90-150-90-150-90-150 — back and forth between cylinder banks.
The uneven firing intervals of the 1962–1977 Buick 90-degree V-6 / General Motors LLC
This gave the V-6 a peculiar sound and feel, both created by the uneven torque impulses. Here’s a graph of those impulses for the odd-fire engine:
Torque impulses diagram for the odd-fire V-6 / General Motors LLC
Because Buick later gave the V-6 an “even-fire” crankshaft, using split crankpins to provide even firing intervals, later critics and historians have often lambasted Buick for not doing that in the first place. However, there were some good reasons why Buick chose the odd-fire design.
The V-6 enabled Buick to cut the price of a 1962 Buick Special by about $100 from 1961 / Bring a Trailer
In engineering terms, the Fireball V-6 was a pretty hasty improvisation, and there’s no question that its major design priorities were to carry over as much tooling and accessories as possible from the small V-8 while creating a six-cylinder engine that would fit in the short, cramped engine bay of the Y-body Special. A small inline six like the Chevy II engine would not have fit, and for budget reasons, there was no chance of Buick creating an all-new 60-degree V-6. Nonetheless, Buick chose the odd-fire arrangement deliberately, and they felt it had some definite advantages.
Here’s how Buick chief engineer Lowell Kintigh explained one of those advantages in the February 1962 Motor Trend:
The torque output [of the Fireball V-6] rises on a power curve similar to that of a V-8 and the performance characteristics in normal-driving ranges are markedly superior to competing in-line Sixes.
From an engineer’s point-of-view, the design is efficient. The two banks operate almost as separate engines, each fed by one barrel of a two-barrel carburetor for equal fuel distribution to all six cylinders. Firing alternates from bank to bank. Symmetrical impulses provide a strong ram effect in log-type intake manifolds and create improved scavenging of exhaust gases.
In his V-6 analysis in the December 1961 Hot Rod, Roger Huntington had previously explained that with the 90-150-90-150-90-150 firing intervals:
There was no torque “stack-up” at any point in the cycle, and the uneven intervals were not noticeable by ear or feel about idling speed. Another important advantage of this final firing order (actually 1-6-5-4-3-2), back and forth across the V, was that the intake suction impulses of the three cylinder on each bank were at evenly spaced intervals of 240 degrees of crank rotation. This meant that the intake manifold could be a simple “log” type, with each side drawing from one carb barrel and no interconnection between them, or no complicated “180-degrees” ducting. This also permitted long, equal length passages that give a noticeable inertia “ram” effect at high speeds.
This paid off in torque. Buick claimed that the 90-degree odd-fire V-6 had up to 10 percent more torque than an inline-6 of similar displacement. For example, the 1962 Fireball V-6, with a displacement of 198 cu. in. (3,235 cc), had a gross torque rating of 205 lb-ft, compared to only 177 lb-ft for the 194 cu. in. (3,177 cc) Hi-Thrift six in the 1962 Chevy II.
The 1962 Fireball V-6 claimed 135 hp and 205 lb-ft from 198 cu. in. (3,235 cc), both SAE gross ratings / Bring a Trailer
The Buick engine did have the benefit of a two-barrel carburetor and a slightly higher compression ratio than the single-throat Chevy II six. However, the V-6’s torque advantage was largely due to manifolding that took advantage of the symmetrical intake impulses Kintigh and Huntington described, which existed because of the uneven firing intervals.
The odd-fire design also provided a surprising benefit in dealing with the inherent imbalance of the 90-degree V-6 layout. An early Buick 90-degree V-6 had two principal imbalances:
- Primary imbalance: A rotating couple (a kind of corkscrew motion) at engine speed
- Secondary imbalance: A horizontal rocking couple, oscillating at twice engine speed.
With the odd-fire crankshaft, the rotating couple had a constant magnitude and acted in the same direction as crankshaft rotation. This meant that Buick was able to completely eliminate the primary imbalance with counterweights alone, WITHOUT the need for a balance shaft like the one used in the Taunus V-4 engine Ford developed for the Cardinal.
The odd-fire V-6 could completely counter its primary imbalance with counterweights, leaving the horizontal rocking couple caused by the secondary imbalance / General Motors LLC
Counterweights couldn’t fix the secondary imbalance, but for a passenger car engine, a horizontal rocking couple is not so bad from a standpoint of vibration and harshness because it’s easier to isolate than a rotating couple or vertical imbalance. Here’s why: Engine mounts have to support the weight of the engine, so they must be fairly stiff in the vertical plane, which more readily transmits vertical shaking to the body and occupants. To deal with horizontal shaking, it’s possible to make engine mounts that are stiff in the vertical plane and soft horizontally, so most of the vibration isn’t transferred to the structure of the car — the engine can just rock from side to side on its mounts, and the occupants may not even notice unless they get out and pop the hood.
So, the bottom line was that while the Buick V-6 still felt and sounded coarse, the odd-fire crank actually helped to keep the engine’s shaking forces at manageable levels — without the extra cost of a balance shaft — and allowed better torque output.
These advantages were compelling enough that some later manufacturers opted for 90-degree V-6s even with clean-sheet engine designs. Probably the most prominent example was the Peugeot-Renault-Volvo V-6, which was also a 90-degree odd-fire V-6, even though it shared nothing with any V-8 design. The designers of that engine acknowledged that the 90-degree design wasn’t quite as smooth as an inline six, but it was smoother than the partners’ existing inline-fours, and the wider bank angle was better for packaging than a 60-degree V-6, which would have been taller for the same displacement.
Volvo called the original 163 cu. in. (2,664 cc) version of the 90-degree PRV V-6 the B27, but it was also offered in various Peugeot and Renault models / Volvo Car Corporation
Buick Even-Fire V-6
After Buick bought back the tooling for the 90-degree V-6 from AMC in 1974, GM began using it in a much wider range of vehicles than they ever had in the ’60s. In the wake of the OPEC oil embargo, buyers of larger and more luxurious cars had started ordering the V-6 for better gas mileage, which made the odd-fire engine’s weird sound and coarse feel less acceptable. The V-6 was light and compact for its displacement, and its combustion chamber design helped to reduce hydrocarbon emissions, but it now ranked poorly in what GM engineers called “pleasability.”
1976 Buick Century Special Landau with V-6 engine / SMclassiccars.com
The revived Buick V-6 was bored out to 231 cu. in. (3,791 cc) so it could share pistons with the Buick 350 cu. in. (5,724 cc) V-8, its cousin once removed / SMclassiccars.com
In the latter part of the 1977 model year, the Buick V-6 got a new “even-fire” crankshaft. Each crank throw was now “split” so that one crankpin would be 15 degrees ahead and the other 15 degrees behind.
The even-fire crank separated each throw into two offset crankpins, set at an included angle of 30 degrees / General Motors LLC
This allowed the cylinders to fire at even intervals of 120-120-120-120-120-120 rather than 90-150-90-150-90-150.
1978 and later Buick V-6s had firing intervals spaced every 120 degrees of crankshaft rotation / General Motors LLC
Although the offset crankpin idea was fairly simple, it took a lot of development to make it work satisfactorily. Buick eventually had to beef up the split-pin crankshaft quite a bit so that it wouldn’t fracture from torsional stress or the bending loads imposed by the engine’s accessory drive.
The new even-fire crankshaft eliminated the odd-fire engine’s uneven power impulses and odd sound, but this came at a cost. Even firing intervals no longer provided symmetrical intake and exhaust impulses, which Buick considered an acceptable sacrifice, and also made dealing with the 90-degree V-6’s primary and secondary imbalance more complicated. As I said above, with the odd-fire V-6, it had been possible to completely eliminate the primary imbalance with counterweights. With the even-fire engine, that was no longer true: Counterweights could reduce the primary imbalance, but its magnitude was no longer constant, and it acted opposite to crankshaft rotation, so it couldn’t be eliminated entirely with counterweights. Also, the even-fire engine still also had a secondary imbalance, which was now a rotating couple rather than the horizontal rocking couple of the odd-fire V-6.
The even-fire V-6 still had primary and secondary balance, but their magnitude and direction were different than the odd-fire engine’s / General Motors LLC
Since they couldn’t completely eliminate either imbalance, Buick engineers decided to arrange the counterweights to eliminate the vertical component. This again left a horizontal rocking couple, which had to be absorbed by the engine mounts as before. With the even-fire crankshaft, the magnitude of this horizontal rocking couple was actually about 20 percent GREATER than in the odd-fire engine: 470 lb-ft versus 391 lb-ft.
Since they couldn’t eliminate the primary imbalance of the even-fire engine completely, Buick engineers used counterweights to eliminate the vertical component, leaving the horizontal rocking couple / General Motors LLC
Here’s an early driving impression of a Buick Skyhawk with the new even-fire engine, from the July 1977 Car and Driver:
Editor Don Sherman found that the even-fire V-6 seemed less coarse and more willing to rev than before, eliminating the “huffing, puffing, groaning, shaking process” of the earlier odd-fire engine. The even-fire engine’s improvement in the latter area probably had less to do with the even firing intervals than with the new, lighter flywheel. Before, Buick had used a very heavy flywheel with the V-6 to try to mask the uneven power impulses; the flywheel of the even-fire engine was a substantial 20 lb lighter. However, Sherman complained:
Unfortunately, there is still a secondary imbalance in the new V-6 to contend with that even-firing does not correct. This flaw makes its presence known by buzzing panels and resonating structure as the engine revs through the body’s natural frequencies. The hood seems alive at 2000 rpm, and by 4000 rpm there’s a deep rumbling from some vague low-forward point. This is actually a compound problem—both engine and structure—that can only be solved by retuning the whole system into true mechanical harmony. But that would mean a major revision to the Skyhawk’s unit body—which you’re not likely to see in the immediate future, if ever.
Based on the 1978 technical paper on the even-fire engine by Buick engineers Dennis M. Manner and Richard A. Miller, what Sherman described as the secondary imbalance was really the unbalanced horizontal component of the primary imbalance, but the point remained: The even-fire engine’s horizontal shaking was actually WORSE than in the odd-fire engine, and in some new and unhappy frequency ranges.
Some GM cars began to receive the even-fire V-6 late in 1977; this is a 1978 Buick LeSabre Sport Coupe with the even-fire turbo engine / Classiccardb
Manner and Miller felt these tradeoffs were worthwhile, making for “a much smoother and quieter engine” overall. They argued that “the primary unbalance of the even firing design, although not desirable, can be isolated from the passenger compartment more easily than the uneven power impulses.”
All production turbocharged V-6s used the even-fire crankshaft — this 1978 LeSabre Sport Coupe has the four-barrel turbo engine, with 165 net horsepower / Classiccardb
However, it still wasn’t ideal, and Buick and later GM Powertrain engineers spent the next 30 years tinkering with the V-6 to make it smoother. In 1988, the V-6 engine (now called “3800”) got a new block with a balance shaft to completely eliminate the primary imbalance, something hadn’t been necessary with the odd-fire design, even though it had been rougher and coarser in other ways.
The balance-shaft-equipped 3800 V-6 was the sole engine offered in the 1988 Buick Electra and Oldsmobile 98 / Bring a Trailer
Obviously, adding the balance shaft was more expensive, it consumed some power, and since it only countered the primary imbalance, it still didn’t make the 3800 quite as smooth as the better 60-degree V-6s of its time.
The 1988 3800 V-6 had 165 net horsepower and a balance shaft to counter the primary imbalance / Bring a Trailer
The early Buick V-6 often gets a bad rap, and discussions of it have tended to come to down to a “odd-fire bad, even-fire good” argument. However, the 90-degree V-6 was always a compromise, which survived as long as it did because its advantages tended to outweigh its flaws. At least for the 1960s, the odd-fire engine had more advantages than it might seem at first glance, even if it felt and sounded kind of odd.
1962 Buick Special V-6 / Bring a Trailer
Related Reading
Vintage Car Life Tech: Buick’s New V6 Engine (1962) – The Beginning Of A Very Long Life (by Paul N)
Vintage Car Life Comparison: 1962 Pontiac Tempest 4, Buick Special V6, Olds F-85 V8 – Decisions, Decisions (by Paul N)
Curbside Classic: Jeepster Commando – Buick V6 (and THM-400) To The Rescue (by Paul N)
Never knew this. Surprised that when Rover bought the Buick V8, they didn’t buy the rights to an alloy V6 version.
The Rover needed engines, with capacities between the 2205cc S4 and 3528cc V8.
Not having a 6 cylinder affected a sales, which the Triumph 2500 fully exploited.
And which the Ford Granada and Vauxhall Royale / Opel Senator would gain UK market share.
The 6 cylinder version of the P6, the P7 was to be a straight 6 development, but would have been nose heavy, and handle poorly.
The Buick V8 engine, would be developed by the Williams F1 team, into a 2997cc V6 (later 2991cc) for the MG Metro 6R4 Group B International Rally Car, with a new head with 4 valves per cylinder and Turbocharging.
This engine would later be developed into the 3498cc version fitted to the production version of the Jaguar XJ220 supercar, after Cosworth worked its magic on it.
Still it really should have been built earlier.
I strongly suspect that there was nothing in their purchase agreement with GM for the V8 to keep Rover from developing a V6 from it. But in reality, there were probably some good reasons not to. An uneven fire V6 would likely not have gone down well compared to the numerous inline sixes in GB and Europe at the time.
In the class of car that would have had a 6-cylinder engine, the bar for refinement was especially high.
Thanks! I’ve read a lot about the strange back-and-forth ownership of this engine, but never read about the strange back-and-forth vibrations!
Your first underhood picture shows ‘flying buttresses’ for the firewall that look like last-minute improvisations to control vibration.
Those buttresses were on all the Y-Body cars, even in 1961 before the V6 was created. These were of course unibodies, and that was presumably necessary to strengthen the cowl and front structure interface, a critical area.
I believe the PRV V-6 also started its life as a 90-degree V-8, at least during its design/development phase.
Also, Car & Driver had issues with the metric system, translating 231ci. into only 781cc, which is still a major failing in America almost 50 years later.
Scrolled down to post this, but you beat me to it, so I’ll add a few recollections…
The B30 I-6 from the 164 was hastily designed, mostly just adding a couple cylinders to the I-4 B20. It wasn’t a very good engine.
Volvo redesigned the 140/160 into the 240/260, and when they did, one of the big changes was changing the front suspension from SLA to MacPherson struts in order to widen the engine bay to fit a 90-degree V-8. And that is indeed what the Peugeot/Renault/Volvo joint venture engine was intended to be.
Then the 1973 Oil Crisis hit. It’s not clear which partner (or maybe it was all three!) got cold feet in light of rising oil prices, but the decision was made to hastily redesign the V-8 into a V-6. Just like the Buick, it wasn’t a very good engine at first, but in its final 3 liter version (seen in the US in the Eagle Premier) it was pretty good – although never as good as the Buick 3800.
Yes, the PRV joint venture started in 1971 to build a 3.5 L V8, something that Peugeot and Volvo were particularly keen on having given the Rover 3.5 V8 in GB and the new Mercedes 3.5 V8 in Germany. And yes, the energy crisis eliminated the need for a V8.
I’m not sure whether a V6 version was contemplated from the get go as a possible derivative or whether that came after the energy crisis.
I’d be tempted to suggest swapping a Buick 3800 into an Eagle Premier, but of course the Premier wouldn’t be worth the trouble.
What the Premier really needed was a transmission swap. The PRV engine wasn’t bad, but the ZF used in the Premier was a durability horror story.
This is not true. The 200 Series Volvo went to MacPherson struts for packaging reasons, but the concern was increasing front crush space as well as allowing more room for emissions-related ancillaries. The PRV project was originally developed for the European market, where there was a growing market for sixes, but tax limits made V-8s prohibitive, especially if they exceeded certain displacement thresholds. (There’s a reason the PRV was just under 2.7 liters!) They chose a V-6 over an inline six because it took up less space and lent itself to casting the block in aluminum to reduce its weight.
I wouldn’t say they had issues with metrics, just a typo which dropped the initial 3. 3781cc is the metric figure.
This is NOT what Peugeot, Renault, and Volvo said about the origins of the project. They said:
(The phrasing is awkward, but the paper was written by two Frenchmen and a Swede.)
The problem with metric conversions is with determining what you’re converting. If you convert cubic inches to cubic centimeters, you’ll get slightly different figures depending on whether you’re converting the nominal displacement (231 cu. in.) or whether, as I make a practice of doing, you convert the actual bore and stroke dimensions and then calculate metric displacement that way. I have a whole spreadsheet of these.
It sounds like the beginning of a joke, that. You know, two Frenchmen and a Swede walk into an engineering paper, and in the resulting linguistic confusion, it appears to suggest they should all invade Greenland.
Do you have a link to that paper? I’m not remotely doubting you, it’s just I’d like to read it. I’ve (rather obviously) always believed the tale about the fuel crisis, bolstered by the fact that the engine was such a pile of crap for a lot of its life. I mean, this is what they came up with when NOT compromised by a hasty change? Blimey!
GM must have done a fine job with the motor mounts and their NVH (noise, vibration & harshness) efforts.
I rode in a friend’s recently purchased used (in 1980) low mileage 1978 Buick LeSabre coupe several times. It had the typical hushed & glass smooth ride quality of this era’s GM big cars. From the passenger seat I didn’t notice any strange or odd vibrations or engine noise.
It was only after she commented that “this car is not as peppy as Dad’s Oldsmobile” that we opened the hood and I noticed the tiny V6 engine looking lost in that huge engine compartment!
She owned the car for at least 6 years that I know of. Other that being slow on merging onto Interstate 10 she never had any problems with this quiet, smooth riding, quite reliable car.
Most interesting. I presumed till now that the V6 was a hasty cobble only, that is, with no useful advantages.
It seems odd to me that the machinery needed to make and machine an aluminium design would have much use in making a cast-iron one: can you even make iron engines with steel dies, which the Buick v8 partly used? One can only imagine that fixed angles of all sorts of complex casting/machining stuff needed to be amortized, likely not having done so with the V8.
You say that the PRV V6 wasn’t related to a V8, but I’ve always understood that it was designed as a 3.5 litre V8 (and the maths bear that out, if you add two more cylinder volumes to the V6’s 2.7-odd litre ones). The oil crisis arrived smack bang in the building of the Dourvin plant, with some machinery being there by June ’73, and the final result not out till October ’74, possibly enough time to alter the design to a six. That engine had some properly weird things to make it smoother, including slightly different ignition timing for each bank and two totally different-sized carburettors. Didn’t work, btw. Engine idled roughly, was a reluctant revver, and contrary to the Buick claim of better torque in an uneven-fire job, it had very little down low or midrange. Also had poor consumption, low specific output, and could often be horribly unreliable. It much later got offset crankpins too.
We got the balance shaft version of the Buick V6 in ’88, and it was tough, very torquey, and quite economical. It was also about as smooth as a washing machine spinning an anvil, and sounded as pleasant as a bar-room brawl. Can’t imagine how unpleasant that old uneven one must have been!
The really expensive machinery in engine building are the giant transfer lines; huge machining and boring and drilling equipment that turn the raw blocks (and heads) into the final products. These are massive, and the basic dimensions, such as the bore centers are fixed and cannot really be changed. This is why they went with the V6, to utilize their huge investment in the line transfer machinery. Drilling and boring and machining aluminum vs. iron might likely only require some change in the actual cutting heads and such, but certainly not the giant machines that ran them.
The casting (foundry) is typically a whole different department and commonly a different facility. I can’t answer the foundry question fully, but clearly the aluminum block required different techniques than the iron blocks. I strongly suspect the aluminum foundry had required signifint investment in new techniques and it may have even been done in a dedicated facility, whereas the iron V6 used more traditional foundry techniques. This is why Buick was quite eager to get rid of casting the engines in aluminum, as the process was much more expensive and there were problems with porosity and such.
“The really expensive machinery in engine building are the giant transfer lines; huge machining and boring and drilling equipment that turn the raw blocks (and heads) into the final products. These are massive, and the basic dimensions, such as the bore centers are fixed…”
Yup. This explains why the bank angles and bore centers are so difficult to change. In fact, “clean sheet” engine families are often based on the previous-design’s specs in order to re-use the machine tooling.
Ford selects 4.38 bore centers for the early-’50s “Y” block…and the Ford “Small-Block” “Fairlane” engines including the 351W, 351C, and 400 also use 4.38 bore centers.
Ford “Lincoln Y Block” has 4.63 bore centers…as did the later FE/FT engine families.
Ford’s ’58 “MEL” used 4.9″ bore centers…which was replaced by the ’68 “385-series–370/429/460 also with 4.9 bore centers.
The Olds “small block” of ’64, and the “big block” of ’65 have the same bore spacing as the original Oldsmobile OHV V8 from ’49.
And the current GM “LT” engine has the same bore spacing as the previous “LS”, which has the same bore spacing as the ’55 Chevy 265.
Chrysler’s Plymouth Polysphere “A” engine bore spacing was re-used on the LA, and then the “Magnum” small-blocks, continuing onto their 90-degree V10s which “should” have been 72-degree bank-angle engines.
There’s heaps more examples.
Perhaps I’m wrong, but I was under the impression that the Buick aluminum V8 was die cast and when Rover purchased the rights to the engine they switched to sand casting. Please correct me if I’m wrong.
The Buick and Oldsmobile aluminum V-8s were primarily made using what GM called semi-permanent mold casting (which in the UK is often called low-pressure die casting), where the exterior surfaces are cast in reusable metal molds and the internal passages are formed using sand cores. (This is distinct from high-pressure die casting, which Chrysler used for its aluminum-block Slant Six, but the terminology can be confusing.) The Rover V-8 was made using sand casting because no foundries in the UK were prepared to do low-pressure die casting, at least not on the scale Rover needed.
Peugeot, Renault, and Volvo said when the PRV engine debuted that it was developed specifically as a compact six, primarily for the European market. I’m sure someone recognized that they could conceivably have made a V-8 of it, but there was very little demand for that in Europe, and a 3.6-liter V-8 would have been brutally expensive to run in France, where two of the partners were based.
The odd fire V6 didnt really appear here except in the occasional Jeep, Buick didnt exist in this country since the early 50s,
But as Justy noted GMH got their paws on the updated version and ran with it until the rattletech V6 replaced it. Having driven both engines in Holden cars I prefer the instant off idle torque of the 3.8 rather than the screamer 3.6.
The old Buick 3.8 seemed to get a lot more refined when they turned it into the Ecotec version (so the VS Commodore-on for us), and like you, I was astonished when the first 4-cam 3.6 replacement started being made (in 2005?) and it not only needed revs, it sounded less refined! And that’s without mentioning that all of them ended up stretching timing chains which cost a fortune to replace….
“Firing order was now 1-6-5-4-3-2 rather than 1-6-5-4-3-2” has me a little confused!
Thanks for the excellent rundown of the engineering challenges involved. I ended up having great respect for this design. A friend had one of these engines in a 1998 Oldsmobile Intrigue, and I liked the car enough to visit the dealer for a test drive. By that time production had changed to a brand-new ohc V-6 and frankly it seemed like a step backwards. It lacked the low speed torque of the old engine and seemed thrashier without any great performance benefit except possibly at rarely used high speeds. For the type of car GM was selling the old engine was a great choice.
I was going to ask the same question.
I enjoyed the DOHC motor in my ’99 Intrigue for the most part, but it was geared to go 65 and keep going faster–it didn’t much like 55-60 mph in my not-flat area because the rpms were too low. I had wanted to buy a softer-riding 3800 Regal, but there wasn’t enough space on the firewall for my left foot.
In my brief experience, GM’s later 3.6 DI V6 had the same problem as the 3.5 only worse because of its more and higher gears and gutless 1200 rpm–I was constantly waiting for a downshift on small inclines. I went back to a Northstar with 4 speed.
I have said GM 3.6 in a Malibu, and you are correct. It’s probably fine for driving in Michigan, but on hill-and-dale roads you have to mash the throttle relentlessly to get it to downshift. I think it’s more the transmission’s fault, though.
Yeah, I should just take that out.
Brings back memories. My first car was a 77 Sunbird with this uneven-firing 231 V6. It did sound weird but was torquey enough around town with the TH200 transmission that is. I never had any problems with it, and eventually, it was donated by my mother who felt it had started to rust too much. Plus my family had other cars to drive that were front-wheel drive, and much better in the snow. I do miss the car but realize it wasn’t GM’s finest hour to be sure. It seemed like the wheel openings were designed to capture mud and snow and start the rusting process. It was easy to change the heater core, though, from the engine bay. I also recall the RTS badge on the dash for “radial tuned suspension”.
We had a two door, 1977 Buick Skylark with the 231ci (3.8L) engine. The engine always made an annoying “tick tick tick” sound. We referred to it as a Buick Nova.
My older brother had a friend with a ’62 Special V6, and I distinctly remember the odd sound it made. But yes, there were no noticeable vibrations once under way.
Thanks for a very thorough explanation! I was under the impression that the primary reason Buick used a three-throw crank on the original 90 degree V-6 was manufacturing cost alone and there was no other justification for using that design. GMC used a split-pin crankshaft on their contemporary 60 degree large V-6 to achieve 120 degree firing intervals and an open-plenum intake manifold in contrast to the original Buick V-6. I remember the ’75-’77 odd-fire Buick V-6’s with HEI had a very strange distributor cap with unevenly spaced secondary terminals.
How many 60 degree V-6’s were sold in the US market and are there any today? I can only think of the GMC and German Ford (used in Capri, Ranger, Explorer and maybe others). Packaging for narrow engine bays in rear drive cars and mini-trucks made it a perfect fit. My ’88 Ranger had the 2.9 version.
90 degree V-6’s from Ford, Chevrolet and Dodge, based on V-8’s were used in mid and full size pickups when in-line sixes where phased out. The 4.2 in my brother in law’s F-150 felt and sounded crude.
Packaging for transverse mounting in low hoodline cars dictated 90 degree V-6 designs which we see today. Am I wrong?
Yes. All V6s sold in the US other than those GM/Ford/Dodge 90 degree V6 were/are 60 degree V6s. Built and sold by the many millions by essentially every manufacturer. Including GM, whose 60 degree V6s starting with the 1980 X-cars were sold by the millions, as well as their more recent developments.
There aren’t a lot of V6s still being made anymore, as most have been replaced by turbo fours. But for decades they were everywhere, along with those 90 degree versions you mentioned.
The 90 degree V6 used by the Dodge Monoco also appeared in both the Eagle Premier & DeLorean.
The non-“Nailhead” Buick engines had more designed-in flaws than you can shake a stick at. And yet, the Buick Faithful will call the 455 a “Hemi Killer” with some justification; at least in Street trim. The combustion chamber efficiency, plus the port sizing makes for wonderful low- and mid-rpm torque.
The V6, the Small block, and the Big block all have the same oiling-system problems starting with an aluminum-bodied, easily-scored external oil pump above the oil level in the sump, requiring the pump to “suck” oil through more than a foot of tubing and drilled/cast passages sealed with gaskets. If the pump loses it’s prime, it’ll spin uselessly until–maybe–it re-primes again. The Buick V6, SB and BB pass oil across the spinning camshaft/cam bearing interface in order to get oil to the left-side hydraulic lifters. Because the cam is grooved, the oil wedge on that front cam journal is disrupted…and the distributor drive gear is overhung off that journal/bearing with no support on the other end. The most-heavily-loaded cam journal/bearing has the least oil film strength. And when that bearing melts, (they do) the thing hemorrhages oil/oil pressure that should be filling left-bank lifters…leading to the Dreaded Buick Ticking/Clattering, and the oil pressure warning light on the dash glowing.
Chevy made the same mistake of grooving the cam journal to flow oil to other engine parts; but only on the 265 engines from ’55 and ’56; by ’57 they’d FIXED that problem by grooving the block under the bearing instead of the cam journal. Film strength improved; and that journal at the rear of the engine didn’t have an overhanging distributor drive gear, or timing-chain forces to begin with. Chevy made the exact same mistake on the first couple years of the Big Block in ’65, fixing it the same way a year or two later. Buick never did fix the problem on the Small Block or Big Block; they waited to groove the block instead of the journal in the V6 until…’88, I think.
It’s really frightful to think that the farther-up the “Sloan Ladder” you go, the worse the engine engineering becomes.
Thank you Schurkey, I was just waiting to bring up the terrible lubrication system that all these Buicks had. Starved for oil each start up, and if parked for a while, complete loss of prime and no oil pressure. These engines had catastrophic failures and short lives because of this. Buick stayed with this design for many years, 25?, until in the 80’s they designed a new oil pump. Cadillac used a similar design that caused the same problems. Yet we see criticism of the Oldsmobile diesel even though the problems were ironed out in only 2-3 years.
I’ve worked on both versions of the Buick V6. I thought I understood the differences, but you taught me something. I never realized the torque advantage provided by the odd-fire version of this engine nor the more simple manifolding the design allowed. Thx for the education Aaron.
Great article! One correction: The actual introduction of the even-fire version was mid-1977, as a running change in ’77 models. Our family had a ’77 Cutlass Supreme with the improved design.
Good point. From memory, the changeover to even fire was a mid-model year move in the ’77 models. Not a lot of odd fire 231 ci. engines were made.
It looks like you’re right, so I’ve amended the main text.
A fine article and history of this engine. I personally owned an odd-fire 225 ci. Dauntless V6 in a ’67 Kaiser Jeep Commando. I believe that Kaiser used an especially large, heavy flywheel on this engine. Many years later, I owned a ’92 LeSabre with a 3800 version. My father had a very long term ’87 Olds 88 with a pre-3800 named the 3.8. That had the first roller type valvetrain and port injection. None of the 3800 modifications yet. That car must have built on a holiday bonus day as it was a true hammer.