What in tarnation do you need a 102.4-liter engine for? If your first guess is raw horsepower, you would be mistaken. This gargantuan 102.4-liter inline-eight-cylinder turbodiesel was delivered just after the conclusion of the Second World War to the U.K. Air Ministry in Scotland, where it undoubtedly deserves honors as one of the largest and most imposing internal combustion engines ever built. <\/p>\n
The purpose of such a colossus was never to propel a vehicle down a highway or a racetrack. Instead, it was designed to serve as a stationary generator, likely providing steady electrical power on a vital Royal Air Force base during the post-war era. The engine in question, the Mirrlees Blackstone JS8, belonged to an illustrious series of heavy-duty industrial power plants manufactured by a company with deep roots in British engineering history. These robust machines were built in various configurations, scaling up to 16 cylinders and producing up to 2,446 horsepower. <\/p>\n
Yet, when examined through the lens of modern automotive engineering, the power-per-liter measure of this diesel beast is surprisingly anemic. To put its massive displacement into perspective, consider that a modern high-performance vehicle like the 2023 Dodge Challenger Demon 170 manages to pump out a staggering 1,025 horsepower from a minuscule 3.0-liter displacement. That translates to an incredible 341 horsepower per liter. By contrast, the Mirrlees Blackstone J-series of engines, even when operating at their absolute highest output, delivered a paltry 24 horsepower per liter. <\/p>\n
Sometimes, however, the true historical and mechanical significance of a machine is not about sheer muscle or high-revving output. Mirrlees specialized in building heavy-duty diesel engines primarily intended for locomotives and demanding industrial applications, earning a reputation as one of the true pioneers of that specific engine architecture. By the time the company was manufacturing the J-series of power plants, they had already been refining their craft for over half a century. Furthermore, the JS8 generated its steady muscle at an ultra-low operating speed of under 1,000 revolutions per minute. In stark contrast, an engineer must spin the modern Dodge’s engine all the way up to 6,500 rpm to extract its maximum advertised output. <\/p>\n
Despite its rugged industrial pedigree, restoring such a historic mechanical artifact is far from straightforward. As Joe Hewes, a dedicated vintage machinery enthusiast who operates the popular YouTube channel Mr Hewes, found out the hard way, a JS8 that has sat rusting and decomposing for several decades is not particularly keen to stir back to life on command. While Hewes is certainly no stranger to a daunting mechanical challenge\u2014having built a reputation for rescuing exceptionally large and complex powertrains from vintage military machinery\u2014the JS8 presented a completely unique set of obstacles. The engine was never engineered to start through anything resembling a conventional modern automotive ignition system. Instead, it relies on a heavy-duty industrial mechanism known as an air start.<\/p>\n
Upon inspecting the vintage power plant, Hewes discovered that the Mirrlees had recorded a mere 720 hours of total service time throughout its long existence. In industrial terms, this means the engine was barely even broken in, especially considering the manufacturer originally trialed these specific power plants to run reliably for up to 1,650 hours before requiring major maintenance. Even with such low operational hours, simply getting the massive internal components to turn over proved to be a formidable journey. A preliminary inspection revealed that the engine was plagued by frozen valves, while the internal spaces that should have been lubricated by clean engine oil were instead stagnant and contaminated with accumulated water from years of exposure.<\/p>\n
In the extended video documenting the rescue effort, viewers can watch the painstaking attempts to start the engine using compressed air, which is the exact method the JS8 would have utilized back when it was actively deployed as a base generator. Unfortunately, this initial attempt ultimately failed. There simply was not enough sustained pneumatic pressure within the system to kick the heavy Mirrlees back to life. Because diesel engines rely on high compression ratios rather than electrical sparks to initiate combustion, turning them over requires an immense amount of mechanical force.<\/p>\n
To truly comprehend the sheer scale of the operation, one only needs to look at the massive physical dimensions of the engine’s internal components. The J-series features an enormous bore of 9.75 inches paired with a 10.5-inch stroke. For comparison, one can look at General Motors’ legendary family of LS small-block engines, the latest iterations of which feature a bore of just 103.25 millimeters\u2014roughly four inches\u2014and a stroke of a similar dimension. A standard car engine of that scale can easily be turned over with a small electric starter motor. <\/p>\n
Reviving something as utterly massive and bound-up as the JS8, however, required a very different kind of ingenuity and industrial horsepower. Overcoming the engine’s decades-old resistance ultimately led to an unconventional makeshift solution: wrapping a heavy-duty ratchet strap securely around the enormous flywheel and leveraging the towing power of a Ford F-Series pickup truck to manually force the crankshaft to rotate. Once that vital milestone was achieved and the internal components finally began to move, Hewes stood by the roaring machine, meticulously fine-tuning the engine while steadily getting coated in a fine mist of oil, looking very much in his element and in his happy place.<\/p>\n","protected":false},"excerpt":{"rendered":"
What in tarnation do you need a 102.4-liter engine for? If your first guess is raw horsepower, you would be mistaken. This gargantuan 102.4-liter inline-eight-cylinder turbodiesel was delivered just after the conclusion of the Second World War to the U.K. Air Ministry in Scotland, where it undoubtedly deserves honors as one of the largest and […]<\/p>\n","protected":false},"author":19,"featured_media":1489,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[411],"tags":[414,412,875,2073,2070,413,2068,1347,2074,1167,919,2071,2072,2067,415,2069],"class_list":["post-1490","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-automotive-industry-and-financing","tag-auto-loans","tag-automotive","tag-back","tag-blackstone","tag-brought","tag-cars","tag-cold","tag-diesel","tag-engine","tag-giant","tag-life","tag-liter","tag-mirrlees","tag-resurrecting","tag-vehicles","tag-youtuber"],"_links":{"self":[{"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=\/wp\/v2\/posts\/1490","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=\/wp\/v2\/users\/19"}],"replies":[{"embeddable":true,"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=1490"}],"version-history":[{"count":0,"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=\/wp\/v2\/posts\/1490\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=\/wp\/v2\/media\/1489"}],"wp:attachment":[{"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=1490"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=1490"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/amercanfirstfinance.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=1490"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}