We can, when needed: heavy diesel engines YaMZ-770/780
Bears from Yaroslavl
To understand the innovation of the YaMZ-770 and YaMZ-780, it's important to briefly trace the evolution of engine engineering at the Yaroslavl Motor Plant. For decades, YaMZ was known primarily for its V-shaped diesel engines of the YaMZ-236 and YaMZ-238 series, which became the mass-produced power plants for trucks, buses, and tractors in the Soviet and post-Soviet periods. Although these engines were repeatedly modernized, their architecture and a number of parameters reflected the technological level of the 1960s and 1970s.
The transition to more modern solutions began with the development of the mid-size inline-series YaMZ-530, designed for mid-size trucks, buses, and special-purpose vehicles. The engine was not built in-house, but with the help of the Austrian company AVL List. Its older brother, the YaMZ-653, was a licensed copy of the French Renault dCi11 diesel engine. It could be found under the hood of, for example, the Ural. The 653 became a temporary solution, filling a power gap of around 400–430 hp. However, dependence on foreign licensing and components remained, and the potential for boosting and localization was limited. In parallel, the YaMZ-650 inline-series diesel engine, similar in design to foreign engines of the same class, was developed using borrowed technologies. However, by the mid-2010s, it became clear that the Russian industry required a completely original heavy-duty in-line diesel engine, designed from the ground up for a wide power range, with a large boost capacity and the ability to meet future environmental and industry requirements.
YaMZ-770. Source: dd76.ru
Initially, development was initiated for military vehicles, which is logical, as this is where maximum localization of components is required. The YaMZ-780 was created for the advanced Bumerang and Kurganets armored platforms, while the YaMZ-770 was developed for heavy civilian vehicles. It's important to note that when developing the cylinder dimensions (130 mm diameter and 156 mm stroke), Yaroslavl designers engaged a foreign engineering consultant, the Austrian company AVL. However, the block, cylinder head, crankshaft, and many other components were designed from scratch, without directly copying existing foreign designs.
Thus, the YaMZ-770/780 became a logical continuation of many years of evolution, but at a new technological level. While the earlier V-shaped engines and even the inline YaMZ-530/650 largely reflected the adaptation and modernization of existing concepts, the 770/780 family became the first completely indigenous flagship platform of heavy-duty inline turbodiesels, developed for high outputs of up to 750 hp with ample boost reserves.
Six cylinders in a row
Competition is the key to technological progress. Yaroslavl engine builders, with their 770/780, found themselves in direct competition with an engine from Naberezhnye Chelny. This was the 910 series, which was produced in collaboration with the Swiss company Liebherr—and here they had to turn to imported partners. The engine is a typical world-class heavy-duty diesel—an inline six-cylinder with a displacement of 12 liters and a power output of up to 560 hp. The Yaroslavl engine is similar in many ways—a six-cylinder diesel with a displacement of 12,42 liters, designed for power outputs of 400 to 620 hp and torque in excess of 2500 Nm.
The YaMZ specifications indicate a slightly higher maximum engine power and a wider power range. This means the engine promises to be more versatile than its competitor from Naberezhnye Chelny. To be fair, there's no direct competition between the KAMAZ-910 and the YaMZ-770/780. The former are installed almost exclusively on KAMAZ trucks, while the latter are designed for a wide range of equipment from various manufacturers. The production version of the YaMZ-770 is eagerly awaited. Confirmed contracts for the new model exist with Minsk Automobile Plant, Ural Automobile Plant, Bryansk Automobile Plant, Minsk Wheel Tractor Plant, Likino Bus Plant, and manufacturers of special-purpose equipment, agricultural machinery, mining equipment, and stationary power units.
YaMZ-780
A brief overview of what the new Yaroslavl diesel engines are.
The engines are based on a four-stroke design with a displacement of 12,4–12,42 liters, a cylinder bore of 130 mm, a piston stroke of 156 mm, and a compression ratio of 17,5. The cylinder head—a monoblock, 24-valve, cast-iron design with an integrated camshaft—is a completely original design, distinguishing both engines from previous models of similar dimensions. The first YaMZ-770 prototypes were demonstrated back in 2018, and serial production was planned for 2025. However, as often happens, the deadlines were pushed back.
Common Rail fuel injection system
The key technological innovation of the new YaMZ family is the Common Rail fuel injection system—a fundamentally different approach to injection compared to traditional unit injectors or in-line fuel injection pumps used on previous YaMZ engines. The essence of the Common Rail system is that fuel is forced under pressure by a high-pressure pump into a common accumulator rail, from where it is supplied to each injector, regardless of the cylinder's firing cycle. The injection pressure of the YaMZ-770 reaches 2000 bar, while that of the military version, the YaMZ-780, reaches 2200 bar. The Common Rail system offers several interrelated advantages. High injection pressure ensures fine atomization and virtually complete combustion of the fuel, resulting in low fuel consumption of 206–210 g/kWh. Electronics control multi-phase injection in real time, which reduces noise, reduces exhaust toxicity and allows the engine to comply with Euro 5 and Euro 6 standards.
Unlike the civilian YaMZ-770, the military version of the 780 is equipped with a gear drive instead of a belt drive, which improves reliability in harsh operating conditions. A key feature of the YaMZ-780 is its dual engine control system—the redundant circuit ensures operation even in combat-damaged conditions. The maximum power of the military engine is 750 hp at a maximum speed of 2300 rpm, and the stated service life is 2500 engine hours. The stated service life of the YaMZ-770 family of engines before overhaul is up to one million kilometers—a figure comparable to the best global counterparts in its class.
Both engines are structurally similar and share a number of features with the YaMZ-650, but differ in their completely original components—the cylinder block, cylinder head, and crankshaft. An additional military-applied advantage of the YaMZ-780 is its multi-fuel capability.
The civilian YaMZ-770 is equipped with a single-stage turbocharger with intercooling in an air-to-air heat exchanger mounted directly on the engine. Cooling the compressed air before it enters the cylinders increases its density and allows for more efficient fuel combustion in each cycle, increasing power and reducing thermal stress on components.
The YaMZ-780 is equipped with a more complex two-stage turbocharging system with air-to-water intercooling. Two-stage air compression allows for significantly higher boost pressure. An air-to-water intercooler is more compact and efficient than an air-to-air intercooler, which is especially important in the confined spaces of armored vehicles. It is this two-stage turbocharging that largely accounts for the military engine's 750 hp from a displacement of 12,4 liters—an exceptionally high boost for an inline-six engine.
BMP "Kurganets"
The military version has a fundamentally different cooling system compared to the civilian version: a dual-circuit system with separate "hot" and "cold" circuits. The hot circuit cools the block and cylinder head—heat-stressed areas that require maintaining high operating temperatures for maximum efficiency. The cold circuit serves two charge air coolers, a generator, and a voltage and current regulator. This architecture allows for optimal management of the engine's thermal balance under any operating conditions—from arctic cold to desert heat—without compromising reliability.
In addition to the main electric starter, the military YaMZ-780 engine is equipped with a pneumatic starter that cranks the engine using compressed air. This provides a backup starting mechanism in the event of a discharged battery or damage to the electric starter. Serial production of the YaMZ-780 was planned for the Tutaev Experimental Repair Plant in the Yaroslavl Region. There is no word yet on the engine's serial production (like the arrival of the Boomerang and Kurganets in the military), but its civilian counterpart is expected to enter production in the fall of 2026.
Particularly significant in the context of technological sovereignty is the extensive use of Russian components: turbochargers, common rail fuel injection system, cylinder-piston assembly, plain bearings, high-power fasteners, cast iron and aluminum castings—all of these are produced by domestic companies. This makes the YaMZ-770/780 family one of the most localized modern Russian engines.
Information