2 strokes.

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461 K vues · 10 K réactions | ห้องเรียน bosozoku ตอนที่ 21 วันนี้เสนอตอน ซัมปาจิ หรือ 38 (GT380นั่นเอง) ซูซูกิ จีที 380 ได้ฉายาว่า ซัมปาจิ หรือภาษาญี่ปุ่นเรียกว่า サンパチ Sanpachi แปลว่า 38 . ทำไมถึงเรียกมันว่า ซัมปาจิ ที่มาของมันมาจาก 38 แรงม้า ของต

ห้องเรียน bosozoku ตอนที่ 21 วันนี้เสนอตอน ซัมปาจิ หรือ 38 (GT380นั่นเอง) ซูซูกิ จีที 380 ได้ฉายาว่า ซัมปาจิ หรือภาษาญี่ปุ่นเรียกว่า サンパチ Sanpachi แปลว่า 38 . ทำไมถึงเรียกมันว่า ซัมปาจิ...
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Stolen from Facebook so may not be 100% accurate...

Aprilia 250cc V-Twin two-stroke engine stands as one of the most sophisticated and successful small-displacement racing powerplants ever built. Developed for the legendary Aprilia RS250 and their Grand Prix 250 race bikes, this engine perfectly captured the essence of the two-stroke era — compact, ferocious, and razor-sharp in response. It embodied Aprilia’s engineering philosophy of combining lightweight design with precise power delivery, earning countless victories and cementing the brand’s reputation as a force in mid-displacement racing.

At its heart, the Aprilia 250 V-Twin was a liquid-cooled, 90-degree two-stroke engine derived from the proven Suzuki RGV250 unit, which Aprilia extensively re-engineered to meet their performance standards. Displacing 249cc, it produced between 65 and 95 horsepower depending on specification — astonishing figures for such a small engine. With twin cylinders, reed-valve induction, and electronically controlled exhaust power valves, it delivered explosive acceleration above 8,000 rpm, yet remained tractable enough for skilled riders to manage through corners. The powerband was narrow but devastatingly effective, producing that signature shrieking exhaust note that defined two-stroke racing.

The engine featured a six-speed close-ratio gearbox, advanced lubrication via a separate oil injection system, and lightweight crankshafts to minimize rotational mass. Aprilia’s race-tuned versions used hand-finished ports, optimized exhaust expansion chambers, and digital ignition systems to extract every ounce of performance. The precision of its engineering meant that every component — from the carburetors to the cooling system — was designed to operate in perfect balance at extreme rpm levels, often exceeding 12,000 revolutions per minute.

In the RS250 street variant, this engine was slightly detuned but retained all the soul of the racer, delivering around 70 horsepower in a package weighing under 150 kilograms. The result was one of the most exhilarating riding experiences ever put on the road — sharp throttle response, immediate power, and a sound that could only come from a finely tuned two-stroke twin. For professional racers, the same layout powered Aprilia’s factory GP bikes, which carried riders like Valentino Rossi, Max Biaggi, and Loris Capirossi to international glory in the 1990s.

Today, the Aprilia 250cc V-Twin two-stroke is remembered as a masterpiece of mechanical purity and performance. It represents the final evolution of an era when racing engines were simple yet spectacular, relying on raw engineering skill and precision tuning rather than electronics or rider aids. Its mix of power, lightness, and character ensures it remains one of the most admired and collectible engines in modern motorcycling history — a true icon of the two-stroke age.
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Barry Hell said:
Stolen from Facebook so may not be 100% accurate...

Aprilia 250cc V-Twin two-stroke engine stands as one of the most sophisticated and successful small-displacement racing powerplants ever built. Developed for the legendary Aprilia RS250 and their Grand Prix 250 race bikes, this engine perfectly captured the essence of the two-stroke era — compact, ferocious, and razor-sharp in response. It embodied Aprilia’s engineering philosophy of combining lightweight design with precise power delivery, earning countless victories and cementing the brand’s reputation as a force in mid-displacement racing.

At its heart, the Aprilia 250 V-Twin was a liquid-cooled, 90-degree two-stroke engine derived from the proven Suzuki RGV250 unit, which Aprilia extensively re-engineered to meet their performance standards. Displacing 249cc, it produced between 65 and 95 horsepower depending on specification — astonishing figures for such a small engine. With twin cylinders, reed-valve induction, and electronically controlled exhaust power valves, it delivered explosive acceleration above 8,000 rpm, yet remained tractable enough for skilled riders to manage through corners. The powerband was narrow but devastatingly effective, producing that signature shrieking exhaust note that defined two-stroke racing.

The engine featured a six-speed close-ratio gearbox, advanced lubrication via a separate oil injection system, and lightweight crankshafts to minimize rotational mass. Aprilia’s race-tuned versions used hand-finished ports, optimized exhaust expansion chambers, and digital ignition systems to extract every ounce of performance. The precision of its engineering meant that every component — from the carburetors to the cooling system — was designed to operate in perfect balance at extreme rpm levels, often exceeding 12,000 revolutions per minute.

In the RS250 street variant, this engine was slightly detuned but retained all the soul of the racer, delivering around 70 horsepower in a package weighing under 150 kilograms. The result was one of the most exhilarating riding experiences ever put on the road — sharp throttle response, immediate power, and a sound that could only come from a finely tuned two-stroke twin. For professional racers, the same layout powered Aprilia’s factory GP bikes, which carried riders like Valentino Rossi, Max Biaggi, and Loris Capirossi to international glory in the 1990s.

Today, the Aprilia 250cc V-Twin two-stroke is remembered as a masterpiece of mechanical purity and performance. It represents the final evolution of an era when racing engines were simple yet spectacular, relying on raw engineering skill and precision tuning rather than electronics or rider aids. Its mix of power, lightness, and character ensures it remains one of the most admired and collectible engines in modern motorcycling history — a true icon of the two-stroke age.View attachment 151374
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Wasn’t the RS engine the RGV engine?
 
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