THE MOST LEGENDARY 1970s Diesel Engines That a Fuel Crisis Tried to Kill — They SURVIVED!

[00:00:00]In December of 1973, a long haul driver named Russell Kemp sat in a fuel line three hours long outside Harrisburg, Pennsylvania, watching pumps run dry one truck stop at a time while the Arab oil embargo choked off nearly a tenth of the country's fuel supply overnight. Within two months, independent truckers were blockading interstates from Ohio to New Jersey, demanding relief from [music] prices that had doubled overnight and engines that were never built to run on rationed diesel. Russell survived that shutdown. But the engine sitting under his hood barely did. And it was not the only one. By the end of this list, you will know five real 1970s diesel engines that the fuel crisis was supposed to kill outright. and exactly how each one refused to go down. Number five, the Caterpillar V225.

[00:01:03]Pop the hood on a 1970 Ford Louisville [music] and you would not find a single Ford part inside the engine bay. You would find a heavy industriallooking Caterpillar in line six wearing a Ford badge, a big iron block built first for generators and construction gear, then dropped into a highway truck almost as an afterthought. That decision sounds strange until you remember Ford did not build its own heavy diesel yet [music] and needed someone else's iron just to stay competitive against Cumins and Detroit. Caterpillar called this particular engine the 1160 inside its own catalog.

[00:01:40]Ford sold the exact same block to fleet buyers as the V225.

[00:01:45]And from 1968 to 1974, it powered the heaviest Louisville trucks running coast to coast, loaded down with real freight on real interstates. 225 horsepower does not sound like much today, but that is roughly what four family sedans of that era produced combined. all funneled through one block sitting behind a single grill and turning a drive shaft built for 18 wheels instead of four. Ask yourself how a truck maker survives an oil shock while depending entirely on someone else's engine design for its heaviest trucks on the road. The answer for Ford was that it barely did. Ford's own sales literature from the period openly listed a whole ladder of these Caterpillar 6s. The V150, the V175, the V200, and the V225.

[00:02:39]Proof that fleet buyers were making this exact [music] horsepower and fuel bill tradeoff on every single order form they signed. Then the fuel crisis hit and Ford went looking for something that burned less and weighed less, landing on Caterpillar's own 3208 by 1975.

[00:02:58]That is right, Caterpillar's other truck engine effectively replaced Caterpillar's first truck engine. The 1160 never got a second act inside a Louisville cab, but the same core design kept turning inside generators, water pumps, and marine engine rooms for another two decades. quietly outliving the very trucks it had been pulled out of. It did not survive the fuel crisis in the cab it was built for. It survived everywhere else instead. And if you think getting outgunned by your own manufacturer's next engine is rough, wait until you hear what a ruined reputation nearly did to the engine coming up next. Number four, the GMC Torlow DH637.

[00:03:57]The next engine on this list came from a company that already built its own diesel and decided to build a second one anyway just to compete with itself.

[00:04:07]General Motors already had the Detroit Diesel two-stroke line running strong in heavy trucks, but GMC's own truck division wanted something cheaper for its conventional lineup. So, it went looking inside its own parts bin instead of outside the company. In 1966, GMC took its own big block gasoline V6 architecture, the same basic design already working hard in dump trucks and delivery rigs, stretched it into a V8, and called the diesel version the Toro flow, named for the tooidal swirl its combustion chamber punched into the incoming air. The DH637 displays 637 in. That means more raw [music] internal volume than 10 small four cylinder car engines combined. And it made somewhere between 195 and 220 [music] horsepower, depending on the tune. It went straight into GMC's heaviest 9,500 series conventional trucks, the ones meant to run coast to coast with a full trailer behind them. Here is something most people do not know. Early Toro flows were geared to spin all the way up to 3,200 revolutions per minute. That means the crankshaft was allowed to spin far faster than a big heavy diesel like this [music] could actually survive. And the failures that followed nearly killed the engine's reputation before the fuel crisis even started. GMC pulled the red line back to 2,800 and the failures mostly stopped. But the damage to the Toro flow name was already done. Why would a fleet manager gamble on an engine that had already burned him once, right when fuel prices were doubling and every single dollar of downtime mattered more than ever?

[00:05:56]Most fleet managers did not take that gamble, and GMC quietly wound the heavy Toroflow V8 out of truck production by the mid 1970s.

[00:06:07]But a scattered handful of operators refused to let it go, including one water hauling outfit, according to owners who kept the engines running that reportedly ran a whole fleet of Torlow tankers for close to 20 years after GMC had moved on to something [music] else.

[00:06:24]The fuel crisis did not save the Torlow's reputation, and it did not save GMC's confidence in the design. It just could not quite finish the job of erasing it completely.

[00:06:36]The engine coming up next did not just survive a bad reputation. [music] It got turbocharged, redesigned, and stretched practically [music] to the breaking point. And it is about to make this whole list look tame. Number three, the D AFDKS.

[00:07:04]Every engine so far on this list belongs to an American story, but the fuel crisis was a global event. And one small Dutch truck maker answered it with a piece of engineering nobody else in Europe had finished building yet. In 1973, the very same year the oil embargo began, DAFF unveiled the 2800 with an engine called the DKS sitting under a brand new tilting cab. This was not a routine turbocharger. This was the first production diesel in Europe running a turbocharger [music] and an intercooler together. That means the incoming air gets compressed for more power and then cooled back down before it ever reaches the cylinder. So, the engine makes more [music] power without burning proportionally more fuel to get it. Every rival on the continent was still choosing one or the other.

[00:07:56]More power at the pump or better mileage on the odometer. and DAFF built a cab specifically to prove [music] the choice was no longer necessary. How do you convince an entire industry that [music] horsepower and fuel economy are not actually enemies?

[00:08:13]Displacement was 11.6 6 L, 710 C in [music] roughly the internal volume of six ordinary car engines stacked into a single straight six block and it produced [music] 320 horsepower along with 929 lb feet of torque. Think about that for a second. Picture D. AF's own engineers in Eintoven in 1973, staring at the exact same trade off every single rival was stuck with more [music] power always meaning more fuel burned and simply refusing to accept that as a permanent law of diesel engineering. If you have ever hauled freight across the Alps in a 1970s cabover, you already know how rare that particular combination actually was. The DKS was not perfect. Early units suffered turbo lag and cooling headaches that kept DAFF's dealers busy well into the mid70s, and buyers complained about it loudly. But almost nobody walked away from the [music] 2800 over it because the alternative on the market was an engine that simply could not [music] deliver both numbers at the same time.

[00:09:26]Worth remembering that DAFF's turbo intercooling idea was so far ahead of the rest of the industry that the basic principle eventually became standard equipment on nearly every heavy diesel built afterward all the way into the modern era. The DKS did not just survive the fuel crisis. It was built as a direct answer to it and it won that fight outright. But everything you have heard so far is only a warm-up for the engine that spent the entire 1970s fighting off extinction from every direction at once. Coming up, two engines the fuel crisis [music] attacked harder than anything you have heard so far, including one that ended up serving a completely different branch of government entirely. If you want to keep seeing videos like this one, subscribe so you never miss what is coming next.

[00:10:17]Number two, the Mac V8.

[00:10:32]Mac trucks ran two totally different diesel engines through the 1970s, and by the end of the decade, one of them had to prove it deserved to survive the [music] fuel crisis at all. Picture a V8 diesel wearing the same Bulldog badge as every inline 6 Mac ever built. Sitting lower and wider in the frame than anything else in the lineup and sounding nothing like the Maxine 6 cylinders that made Mac famous on every highway in the country. Most drivers who grew up on Mac's inline [music] sixs barely knew this V8 existed at all. Tucked away in a smaller share of the lineup and overshadowed by its own more famous siblings. That is the MAC V8. First introduced in [music] 1962 as the END864, a 255 horsepower thermodyine engine built for Max B, C, and F series trucks.

[00:11:27]By 1969, MAC redesigned the entire block and split it into two personalities. The ENDT865 got the Maxine treatment. That means a wide flat [music] torque curve that let drivers pull hard through fewer gear changes, tuned between 285 and 325 horsepower, while the NDT866 stayed a conventional diesel, and pushed as high as 375 horsepower. Here is the kicker. Mac kept selling both versions all the way through 1980, straight through the oil embargo, the independent truckers shutdown, and the second energy crisis [music] in 1979 without ever once pulling the V8 from the catalog.

[00:12:16]Ask yourself how an engine survives two separate national fuel emergencies in the same decade while every one of its rivals races towards smaller, more efficient designs.

[00:12:29]The honest answer is that it barely did.

[00:12:32]One longtime Max salesman [music] from that era has said openly that he was reluctant to spec the Maxadine V8 for customers, [music] worried that the torquy curve paired with a 5-speed transmission would lug the engine hard enough to blow head gaskets. And that reputation followed the [music] V8 for years. By the late 1970s, Cumins, Detroit Diesel, and Caterpillar were all [music] chasing 400 horsepower with the KT, the 8V92 Turbo, and the [music] 3408 and Max aging V8 suddenly looked like a fuel crisis relic standing next to a new generation.

[00:13:12]What does it take to convince an engine designed back in 1962 that it still belongs in a 1980 catalog? So, Mac did something [music] almost nobody expected from an engine this close to the end of its life. In 1976, it bored and stroked [music] the same basic architecture out to 998 cub in badged the E1000.

[00:13:35]And by 1978, it was a regular factory option, putting Mac directly into the 400 horsepower club its rivals had built without any help from this old V8 at all. And that is not a small accomplishment for one engine [music] designed to survive two fuel crises, a damaged reputation, and a horsepower war it was never originally built to fight.

[00:13:59]The MAC V8 did not [music] just outlast the fuel crisis. It used the pressure of the fuel crisis as the exact force that pushed it into becoming something bigger than it had ever been before.

[00:14:13]If you drove one of these through the Alaganis with a full load in the back, you already know exactly which version I am talking about, and you probably have an opinion about which [music] one deserved the name Maxadine more. But nothing on this list prepared drivers for an [music] engine that the fuel crisis pushed completely out of civilian trucking and somehow never managed to kill at all.

[00:14:37]E number one, the Cumins V903.

[00:14:50]Every engine [music] on this list found a way to survive the 1970s. The engine at number one did something almost none of them managed. It got pushed completely out of the trucking industry and is still being built brand new today, just wearing a different uniform entirely. Picture a V8 diesel-shaped nothing like the tall inline [music] sixs that dominated American trucking.

[00:15:13]Short enough and compact enough to tuck under a cab over engine hood where a six-cylinder simply would not fit no matter how the frame was designed.

[00:15:23]Cummins built it specifically to solve a packaging problem that its own NH and NTC six-cylinder engines could never solve on their own. Since a tall inline 6 needs a long hood or a raised cab floor that cuts directly into usable cargo length, they called it the V903 93 cub [music] in 14.8 L, which is roughly the internal volume of eight motorcycle engines poured into a single BQ V8 block. International Harvester put it into the ACCO 3070.

[00:16:00]Ford put the turbocharged version into the Louisville LNT9000.

[00:16:05]Both trucks used it to haul real freight coast to coast throughout the 1970s. And for a while, it looked like Cumins had solved the short hood horsepower problem for good. Naturally, aspirated versions produced around 265 to 290 horsepower, roughly what two modern V8 [music] pickup truck engines make combined.

[00:16:26]delivered instead through one heavyduty crankshaft built to survive a million miles of interstate abuse. How does an engine built to solve one very specific packaging headache end up getting blamed for an entirely different problem it never created? Because that is exactly what happened once the oil embargo hit and the fuel economy conversation swallowed [music] the entire industry whole. A V8 diesel is mechanically thirstier per horsepower than a big inline 6 turning the same power at lower engine speed. And once fleets started counting every single gallon like it was gold, that math worked [music] against the V903 every time a purchasing manager sat down with a spreadsheet. Picture a stack of competing fleet bids from the mid 1970s.

[00:17:15]one for a V8 lineh hall tractor and one for a six-cylinder alternative with the exact same fuel economy line circled in red on every single sheet because that circled number decided far more purchasing decisions across [music] the industry than any driver's personal opinion ever did. If you spent any real time behind the wheel of an ACCO or an early Louisville, you already know how hard that V8 hit off idle, and you probably have strong feelings about whether the fuel numbers ever told the whole story. Emissions rules kept tightening through the rest of the decade and into the next one. And fleet after fleet that had loved the V903 for its packaging and its pull switched over to something that sipped less diesel [music] per mile.

[00:18:04]The turbocharged version hung on longer in the Louisville lineup than almost [music] anyone expected, but the writing on the wall never really went away once the industry decided fuel economy [music] mattered more than any other spec on the sheet. And that is not a coincidence. Every single V8 highway truck engine Cumins built eventually lost its place in mainstream lineh hall trucking to leaner, more fuelefficient designs, specifically because of the pressure the fuel crisis created and never once let up on. Yes, you read that [music] right. The exact engine that could not survive as a civilian highway truck motor never actually stopped being built at all. Cummins kept the 903 architecture alive by pouring it straight into military hardware. And today, that same basic 90deree V8 design, turbocharged and [music] after cooled, that means the compressed intake air gets cooled a second time before it ever reaches the cylinder, is rated at [music] 675 horsepower and powers the United States Army's Bradley fighting vehicle, one of the most heavily produced armored vehicles [music] in the entire American arsenal. sound familiar to anyone who has ever watched an engine get declared dead by an entire industry only to find out decades later that it never [music] actually stopped rolling off a production line. The fuel crisis did not just fail to kill the Cumins V8.

[00:19:34]It could not even manage to kill it a little. It just changed the paint job from highway red to army green and kept the exact same block running proudly under a completely different flag. Five engines, one decade, and not a single one of them died the way the [music] fuel crisis and its beam counters expected them to. Whether that meant getting outlived by its own replacement, surviving on in a handful of loyal fleets, winning the fight outright [music] with better engineering out of Europe, growing into something four times its original size just to keep pace, or getting drafted straight into the United States Army. Which one of these deserve to survive the least? And which one do you think actually earned it? If you ran an ACCCO, a Louisville, a Mac V8, or anything wearing a DAFF badge through the 1970s?

[00:20:28]Drop the real story in the comments because the people who actually drove these through the embargo tell it better than any script ever could. If you want more videos like this one, subscribe so you never miss what is coming next. See you in the next one.