The Mack diesel V8 was unique in a number of ways, most of all in just being the only really successful four-cycle diesel V8 designed for big trucks. It was a powerhouse from day one and developed into the legendary Mack E9, an engine still held in high esteem for its huge power output at the time (up to 500 hp) and its distinctive thumping throb of its exhaust which made it instantly recognizable when hard at work.
There were higher output versions made for marine and other uses (up to 1000hp), and today the E9 is often boosted to 3000 hp in modified racing and pulling trucks. Although Mack gave up on the big V8 in 2003, back in 1962 they sent some V8 blocks to Scania in Sweden which spawned a line of Scania V8s that are now the most powerful road truck engines with 770 hp.
The Mack V8 has a long and powerful history.
Before we go back in time to the origins of the Mack V8, let’s take in just what makes these engines so appealing, in terms of their unique hammering exhaust, so different than the typical inline sixes. Here’s one pulling up a grade, followed by a Kenworth with a DD 8V92, the other successful big truck V8, but obviously with a very different sound due to being a 2-cycle engine.
Mack Trucks of Allentown PA. was an early adopter of diesel engines for commercial trucks. In the 1930’s Mack was one of the largest manufacturers of trucks in the U.S., and early on was aware of the diesel engine’s potential to be more efficient and durable than the large gasoline engines typically in use at the time. Mack started experimenting with diesel engines as far back as 1928 and Mack engineers had spent time in Europe researching various diesel engine designs, including those of Mercedes-Benz.
Throughout the ’30’s Mack built numerous experimental diesels including 2 stroke designs and conducted much testing of not only their own prototypes but also diesels from other engine manufacturers. Mack discovered that one of the biggest challenges to designing a practical diesel engine for trucks was the ability to control peak pressure in the cylinder for durability and provide for a useful R.P.M. operating range. The solution to both of these issues lie in the fuel injector and combustion chamber design. Given the available technology of the day, Mack engineers felt the Lanova ‘Energy Cell’ combustion chamber showed the most promise and incorporated it into their first production diesel engine, the 131 H.P. ED 519 of 1938.
Interestingly, Mack also offered the various Lanova-chambered Buda diesels as options in their trucks alongside the ED 519. The Lanova cylinder head design used a pre-chamber to control peak pressure and allowed for lower fuel injection pressure but was also easy to start and had a useable power band for a motor vehicle. The Lanova diesels were a success for Mack and together with GMC and their 6-71 2 stroke diesel powered trucks accounted for most U.S. diesel truck sales before the Second World War.
After the war Mack continued with their Lanova diesels, eventually developing the larger END 672 to stay competitive with GM’s 2 cycle ‘Detroit’ and Cummins, who were rapidly growing their diesel engine market share. In 1950 Mack entered into an agreement with the Swedish commercial vehicle manufacturer Scania-Vabis, allowing Scania to build Mack C-50 transit coaches in Sweden. This turned out to be a somewhat fortuitous event for the future development of Mack diesel engines. While it would seem that Scania was very interested in the fine Mack C-50 transit coach, they were not interested in the Lanova-chambered END 672.
Scania was a highly regarded truck and diesel engine manufacturer in their own right, and equipped their license-built C-50, named ‘Metropol’, with their own 11.3L D820 8 cylinder in-line diesel. The Scania D820 featured a state-of-the-art direct injection fuel system which offered greater efficiency and higher output than old Lanova design pre-chamber design. It didn’t take Mack’s progressive engineers long to incorporate Scania’s direct injection open chamber design in the END 672, and through a reciprocal agreement created the legendary END 673 ‘Thermodyne diesel’. And so began a long history of cooperation between Mack and Scania.
Mack did very well during the 50’s with their Scania-sourced ‘Thermodyne’ technology, eventually introducing the larger END 711 diesel and turbocharging to stay competitive with GM and Cummins. However, with truck weight regulations becoming less stringent and interstate highways permitting higher speeds, Mack was having trouble keeping up with their competitor’s latest diesels by the end of the 1950’s. In addition, Scania was facing similar issues in Europe. The time was right for further Mack/Scania cooperation, which eventually culminated in the Mack and Scania V-8 diesel engine families.
Mack introduced their new, state-of-the-art END-864 V-8 diesel in 1962, which coincided with the opening of Mack’s brand-new Hagerstown Maryland engine plant. The new V-8 was an 864 cubic inch 90-degree V-8 with a 5” X 5.5” bore and stroke, and it produced 255 H.P. @2300 R.P.M. and 638 ft. lbs. of torque @1700 R.P.M.. Respectable numbers for the day and comparable to the early Detroit 8V-71 and Cummins NH 220 series diesels. The biggest advantage of going to a V-8 design is that it allowed for much greater displacement than Mack’s existing in-line 6 cylinders (the largest being 711 cubic inches), but it was also externally compact and fit well in the Mack C-series short conventional and F-series cabover, particularly the short day cab versions.
The V8 featured paired ‘Thermodyne’ cylinder heads (4 total) and used a Bosch PSJ ‘distributor’ type injection pump. The new V-8 also featured ‘wet’ (exposed to coolant) cylinder sleeves like Mack’s (and Scania’s) 6 cylinder diesels.
Mack’s new V-8 was initially available in certain models of the venerable B series conventional as well as the aforementioned C and F series trucks. By 1966 it was also offered in the new R, U, and DM trucks which replaced the earlier B and C series models. Naturally it didn’t take long for Mack to respond to the competition with the even more powerful twin-turbocharged ENDT-864 which produced 325 H.P. @2300 R.P.M. and a whopping 1099 ft. lbs. of torque, big numbers for the day. Mack also introduced other naturally aspirated versions of the 864 with H.P. ranging from 237 to 270.
While the 864 series was not what I would consider to be a bad diesel engine, being a brand-new design it did have a few issues. The Bosch PSJ pump was a fairly common piece in those days, also used by GMC on their Toro-Flow diesels, and both Mack and GMC found out pretty quickly that these pumps were not very tolerant of dirt and water contamination in the fuel. As such the PSJ needed frequent filter replacement and periodic rebuilding. This was in contrast to the unit type injectors used on Detroit Diesels and Cummins’ ‘P-T’ fuel systems which performed better on bad fuel and neglect.
Mack was likely stuck using the PSJ because it was a compact unit, mounted between the cylinder banks and out of the way of the intake plumbing and turbochargers on the ENDT-864’s. Another issue was the tendency for the cylinder heads to come loose causing head gasket failures. More of a problem on the turbocharged engines, this could be minimized by retorquing the heads every 150,000 miles. However, this is just the sort of thing that truck operators didn’t want to contend with, an expensive additional required maintenance procedure. I have also found mention that the 864’s were somewhat prone to bottom end failures. While I have not found any specific information on such problems subsequent development of the Mack V-8’s included some significant changes to the crankshaft and rod bearings, perhaps indicating that something was amiss. All things considered, Mack’s early V-8’s earned a reputation of being a smooth and powerful engine that required more maintenance and was somewhat more prone to trouble than comparable Cummins and Detroit engines.
Meanwhile, back in Sweden, Mack had shipped over a number of 864 engine blocks for Scania to experiment with in 1962. Scania was testing running prototypes of an 864 based V-8 a few years later but interestingly did not put the engine into production. In fact, Scania didn’t introduce their V-8 diesel, the DS14, until 1969. Significantly, the DS14 was not based on the 864 but on the revised second-generation Mack V-8’s, also new for 1969. Perhaps the reason for the delay was Scania ran into some of the same problems Mack’s 864 customers had experienced, but I think it is probably just as likely that Scania wanted to refine the design to incorporate some of their specific engine design characteristics such as individual cylinder heads, a common practice on European diesel engines.
In 1967 Mack introduced the ‘Maxidyne’ concept on the 673 series engines. This was a diesel tuned to produce a wider powerband with peak torque at lower R.P.M. and maximum H.P. at mid-R.P.M. that did not diminish as the engine reached governed speed. This allowed for the use of 5 or 6 speed transmissions instead of the customary 10 or 13 speed gearboxes, which naturally meant significantly less shifting for the driver. In addition, Maxidyne delivered excellent fuel economy. Maxidyne was such a success it spurred Cummins to develop their similar ‘Custom Torque’ engines. Mack would apply the Maxidyne concept to a revised version of the 864 V-8.
The 1969 Mack introduced two new V-8 diesels that represented an extensive redesign to the basic 864, the 865 which was a Maxidyne version and the 866 which was a conventional diesel. The most significant changes included: A slight increase in displacement, which was the result to changing the bore and stroke to 5.25” X 5” respectively. Larger rod bearing journals, 3.747” vs. 3.497” for the 864. And, the new engines also featured an increase in the number of bolts per cylinder head, going from 10 on the 864 to 14 on the 865/866.
Another major change was all the 865/866 V-8 diesels were now single-turbocharged. This change may have enabled Mack to drop the PSJ injection pump, but regardless of the reason the distributor type pump and its associated issues were gone, replaced by the more reliable Bosch in-line APE type pump. The ENDT 865 Maxidyne produced 285 to 325 H.P. while the ENDT 866 produced 355 to 375 H.P..
Both diesels remained in production until 1980 and were available in many models of Mack trucks, including the R, F, DM, Cruiseliner and Superliner. The reputation of the Mack V-8 had improved, though the Maxidyne versions still seemed to suffer somewhat from head gasket and other issues likely the result of more ‘lugging’ with the 5 speed transmissions. In fact, a well-respected Mack person I know who was selling these trucks in the 70’s told me he was reluctant to sell ENDT865 Maxidyne’s for this reason, the 866’s being very reliable. The engines were also expensive, both in purchase price and parts cost. Fuel efficiency was comparable to competitive high horsepower diesels.
In the closing years of the 1970’s, the Mack 865/866 V-8’s began to be eclipsed by new high horsepower diesels from Cummins, Detroit, and now Caterpillar. Respectively the KT, 8V-92T, and 3408 were all rated at 400 H.P. and above. Mack’s answer to the challenge was the E1000 series, which featured a 5 3/8” X 5 ½ bore and stroke netting 998 cubic inches and H.P. ratings from 360 (Maxidyne only) to 400. While the E1000 got Mack into the 400 H.P. game, the important factor was the new V-8 was capable of a lot more. The first E1000’s were built in 1976, but it appears it was a regular option only from ‘78 to ‘79 in the F (now called Interstater), R, DM, Cruise- and Superliner trucks. In 1980 Mack introduced new simplified engine nomenclature and the E1000 became the legendary E9 series.
the very first Scania V8 sold, to a logging firm in Sweden
Meanwhile, back in Sweden, Scania introduced their 140 series trucks in 1969 with the 350 H.P. DS14 V-8 and in very short order became the most powerful trucks in Europe. This was substantially more horsepower than was commonly available from Scania’s competition in Europe, though there were some ringers like the Detroit-powered FTF’s from the Netherlands. Scania did their homework, in addition to the DS14’s power it also developed a good reputation for reliability, the only real issues with the 140 series trucks were (not surprisingly) transmission related. As Scania’s competition gained on the DS14 in the 70’s Scania updated the engine to 375 H.P. and 1100 ft. lbs. of torque (with uprated transmissions!) maintaining the engine’s reputation for being the most powerful available. Scania trucks equipped with the DS14 even sported the same V8 emblems on their cabs that Mack used.
the first Superliner (1977)
Although Mack was a successful truck manufacturer throughout the 1960’s, they did face tremendous competition from a host of other truck builders, including a number of competitively priced new heavy duty class 8 models from the ‘Big Three’. Mack’s profitability was not consistent and a lack of capital was hampering operations, a situation in part caused by significant expenditures on new truck and engine programs. This drove Mack to seek a partner with deeper pockets in 1964, which they found in a willing Chrysler Corporation. Shareholders of both Mack and Chrysler approved the merger, but unfortunately the Federal Govt. filed an injunction stopping the deal on anti-trust grounds, somewhat surprising considering Chrysler’s small heavy truck market share. Mack eventually did find a partner in the Signal Companies in 1967. In 1979 Renault bought a 10% stake in Mack from Signal, eventually taking full ownership in 1990. This move would eventually have a profound effect on not only Mack but their diesel V-8 engine as well.
Renault’s increasing influence over Mack resulted in some positive changes for the venerable truck manufacturer. Here in North America we saw the replacement of Mack’s mid-range Scania sourced diesels like the ETZ477 (Mack had been relying on Scania diesels for their smaller trucks since the 60’s) with comparable Renault sourced diesels. Mack also introduced Renault-based mid-range trucks like the Mid-Liner which proved quite popular and gave Mack a larger share of the class 6 and 7 market. Mack was not the only beneficiary of the new partnership, for in 1990 the Mack E9 V-8 found a new home in the Renault RVI AE/Magnum series trucks (above) as the top option, rated at 503 H.P.. The Magnum gave Scania some competition, ironically with an engine from the same family as the DS14. However, the real significance of Renault’s ownership of Mack manifested in 2001 when AB Volvo bought Renault’s RVI commercial vehicle operations, which included Mack.
Up until the sale to Volvo, Mack and Renault continued to develop and refine the Mack V-8 with highway versions reaching over 600 H.P. and some special quad-turbo military versions for the French Military developing 1000 H.P.. In addition, Daytona Marine offered marine versions of the E9, some rated around 900 H.P.. Mack had planned a new version of the E9 for 2003 that would have included Bosch electronic unit injection to keep the engine current in regards to output, emissions, and fuel economy.
Sadly, Volvo made the decision to drop the Mack V-8 in 2003 in favor of the Volvo D16 family of large displacement diesels. The Mack V-8 era had come to an end. The Mack Truck faithful have always contended that the Mack V-8 was dropped for political reasons, and given the longstanding rivalry between Scania and Volvo perhaps there could be more than a little truth to the idea. After all, large diesel V-8’s became almost synonymous with Scania, how would it look if Volvo adopted an engine based on the same basic design?
Although the Mack V-8 went out of production in 2003, the Scania V-8 was still very much alive and subject to continued development. Currently available in ratings from 530 to 770 H.P. and fully emissions compliant in Europe thanks to selective catalytic reduction and other technology, the Scania V-8 remains what it has always been, one of the highest regarded diesel engines in Europe. It may be difficult to see much if any of the original Mack design in the cylinder block, but there is no doubt about its parentage. There is still some Bulldog in that breed!
Related CC reading:
Quarryside Classics: Mack R-Series – Rock Solid Since 1966
Truck Show Outtakes: Mack NM8, Scania V8, And Another One – You Will Hear From Us
CC Global: 2022 Scania S530 V8 And 2015 DAF XF 510 Potted Plant Movers – Wallflowers They Ain’t
Great post, chock full of stuff I did not know. Well done.
Pretty sure the last vid is round here, btw (Australia).
Bravo Robert, a very fine piece of reading! (you must be the same person as commenter and Mack adept Bob B, right?)
Recently, Volvo introduced a 780 DIN-hp, 17.3 liter inline-six. So for the time being, they’re sitting on the top of the mountain, power- and torque-wise.
Regarding the Scania V8, there’s this young guy from Florida, Bruce Wilson. He’s the American Mr. Scania V8, so to say. As we speak, a brand new Scania R770 tractor is coming over to his shop in the US. Here’s a recent video, right from the factory and before shipment (numerous videos by Wilson can be found on YouTube).
Yes, one in the same!
Glad you enjoyed the article, and I would like to again say how much I enjoy your articles on European trucks!
Scania’s were imported very briefly to the U.S. in the late 80’s.
Thanks!
Yes, a number of them was sold in the north-east. I always thought only the 6-cylinders, but a few years ago I came across this video of a 143-V8 conventional in Chicago (the ‘3-series’ was introduced in 1987).
Multiple Scania 8-cylinders drive around in Canada too, those are more recent imports of used tractors from Europe.
only 6cylinders were sold in the US becouse of emissions, all v8 you see driving there are later swapped engines or imported trucks by the euro community in the north east.
Thanks Bob for this detailed look at an engine I was only roughly aware of. I distinctly remember seeing that V8 badge on some Macks back in the later ’60s and ’70s and noting their different and distinct exhaust note. I was impressed, but never really followed up on its evolution. And until Johannes D. pointed it out some years ago here, I would never have connected this with Scania’s V8.
And thanks again for yoir assistance with it!
I was a contractor for Mack during the final Renault years / beginning of the Volvo years. The engine being dropped wasn’t the only thing “political” about the move; there was the closure of the (non-union) plant in Winnsboro SC, closure of the Headquarters in Allentown, PA to North Carolina. The union shop in Macungie, PA is still operational, my uncle worked there on the finish line till the day he retired.
Great article, I enjoyed reading it with my morning coffee. In the late ’80s I lived and worked in Northeast BC and at that time the hot setup with the local truckers was an E9-500 with Mack’s 12 speed behind it. Prior to that I don’t recall seeing many Macks in the big power end of the business but plenty of 6 cylinder Maxidynes in Dump trucks and concrete mixers.
It was interesting to read about the earlier V-8s, which I was aware of but knew little about. In areas of Western Canada that had a good dealer Mack did very well in the vocational truck market but didn’t seem to be that popular in highway hauling until the E9 came along.
In those days 500 horses was kind of the “holy grail” and guys tried all kinds of ways to get thier 8V-92s and N series Cummins to produce more power. Some things worked but there were some dubious modifications that produced little but black smoke as well.
You could always spec a K series Cummins or a 3408 Cat, but they were heavy, expensive and very thirsty. For a brief time the E9 hit the sweet spot and seemed to be everywhere. They had thier issues like all big power engines of the day but the biggest objection to them seemed to be that you had to buy a Mack truck to get one, and lots of guys were loyal to Kenworth, Western Star or whatever brand.
They did have a distinctive sound for sure!
Me, too! Love our article because it explains so much about the Mack V-8. I never sold them as my trucks that I sold were International, GMC, White GMC, Autocar, and Volvo. The Mack is highly respected where I live in The New York metropolitan area.
Superb article Bob. Knew Mack and Scania had some collaboration over the years but not to this extent. Thanks!
What an interesting deep dive into the world of heavy metal haulers and the Big Mack V8 that motorvated them. “Today the E9 is often boosted to 3000 hp in modified racing” holy crap, I wonder why large truck racing isn’t more common in the US. Are we not the land of brodozers. One would think large truck races with that kind of hp would be far more prominent.
Thanks Bob
Great piece I knew there was a tie between Scania and Mack,they were a great engine theres still a few Ultraliners on the road here but most survivors are stored away, My last job had several Molvo Granites which are OK to drive cramped, uncomfortable and noisy that hasnt changed, the switchgear has strange locations its the same as a regular Volvo why couldnt the leave it where it was having to reach over to the far side of the dash to force a gearshift or engage the retarder is just stupid,Volvo trucks are much nicer on humans.
Great article – I knew the outline, but there are a lot of details that I didn’t.
I understand that the earlier Scania 4/6/8 in-lines used a Leyland-licensed DI system, so there’s sort of a PACCAR connection in there, too.
Crankshafts of big V8s tend to be a bugbear – having to put two conrods on the same journal forces the bearings to be very narrow and everyone seemed to make the mistake of not using a large enough diameter to compensate – at least initially. They tended not to take to lugging terribly well.
Especially the Germans were fond of big V8, V10, and even V12 (Magirus-Deutz, air cooled) truck diesels.
I remember Berliet and Iveco also offered in-house V8 engines in heavy on-highway trucks and tractors.
But by now, a V8 is truly a specialty and Scania-only (in Europe, anyway).
Isuzu also offfered a line of large V8/V10/V12 diesels in their C/E ‘Giga’ heavy trucks. The 12PE1 was a 20L natuarly aspirated monster that was highly regarded throughout Asia.
Right, it was (Kiwi)Bryce who mentioned their existense, IIRC, somewhere down the line. Isuzu doesn’t go beyond the 7.5 tonnes GVWR N-series here.
Interesting stuff, pretty much all new to me. Thanks for this!
Good information on the V8. My dad was a Mack man through and through. Sold them, operated them and helped quite a few people who could follow common sense make a lot of money with them. The 6 cylinder Maxidynes were amazing. But the 375 was a legend in the logging and heavy equipment hauling world. It was just a beast. We had one in a R700 with a 12 speed, dynatard, 56,000 pd rears, double frame and walking beam rear “suspension”. As in no suspension. That thing would just embarrass anything on the road. It was not fancy but it was pure magic. Big straight pipe up the right side. Not real loud but very mean sounding unlike anything else. Weak spot for this one was the clutch for real heavy pulls and watch the fuel pump. Once it starts to smoke you know you better get it into the shop before it gets real expensive.