PROBLEM #175
Just score
In a discussion among technicians, a note was shared about a Nissan Note and its four-speed automatic transmission, followed by a remark about a Rio with a six-step transmission. The question arose: why do many modern cars use an even number of gears in automatic gearboxes? Some cited Mercedes and others as examples. The core request remains: help the driver understand the gear count pattern and its purpose in today’s vehicles.
The challenge is not a quick verdict. The solution should be delivered with depth and clarity. Contest submissions were requested before November 1, 2022, to a Moscow address with a postal code of 107045, Seliverstov per., 10, Building 1, or via email. Persistent notes suggested providing a reliable contact method as well. [Citation: Contest guidelines, industry archive]
Another part of the historical context appears in the July 1 results of the Connoisseur Contest. Readers were asked to explain why thirty years ago some cars started easily after a long stop at the dealership, while others required more effort and patience.
The winning answer explained in detail how fuel and ignition systems interacted during cold starts, highlighting the role of high-pressure fuel supply and carburetion in older engines. It described how a booster or priming system affected air and fuel balance, and how vacuum in the intake manifold influenced starting behavior during the initial crank revolutions.
In older domestic cars, the carburetor played a key role in enriching the mixture for cold starts. A separate enrichment system was used in many household carburetors, sometimes referred to as a manually controlled suction valve. During the first cranks of the engine, a strong vacuum formed in the intake manifold, driving fuel flow through various channels. As the engine spun up, the vacuum increased, and the exhaust system’s muffler often opened slightly to avoid flooding with fuel.
Some carburetors, such as noted examples from European and import lines, managed this process fairly well. Older designs like the K-126 could be temperamental, requiring multiple pushes of the accelerator to ensure sufficient fuel delivery to the intake manifold through the accelerator pump.
Long-term parking created its own challenges. The float chamber in the carburetor could leak, exposing fuel to the atmosphere and leading to evaporation, especially when the engine had been hot. The mechanical fuel pump would only operate when the engine started, and valve tightness varied. In some designs, pumps were mounted high, causing delays in fuel feed, while in others, such as certain domestic blocks, a low mount and a full tank helped avoid these issues.
Early foreign cars presented several variations. Carbureted engines often featured automatically operated choke valves to ease starting, and some pumps were sealed, lacking manual levers that were common on domestic cars. A few engines used mechanical fuel injection systems, with devices like the K-Jetronic enriching the mixture; however, the fuel supply to the tank was typically driven by an electric pump that activated with ignition, or even when the door was opened in some modern cars.
Diesel-powered vehicles required a different sequence altogether. Starters for diesel engines depended on seasonally adjusted fuel, sufficient crankshaft revolutions, and healthy glow plugs to heat the combustible mixture. If any of these conditions failed, starting could become a dragging ordeal rather than a clean, steady start. The current era, by contrast, benefits from reliable priming and ignition systems, ensuring smooth starts in most weather and usage conditions.
Today, automotive startups in contemporary vehicles are generally straightforward and dependable when the systems are maintained correctly. The improvement in fueling and ignition control has made modern starts routine rather than exceptional.
In closing, the discussion and the winning solution highlight how historical fuel delivery and starting mechanisms shaped modern car behavior and reliability. The progress from carburetors to electronic fuel injection and efficient fuel pumps has reduced the friction in starting across climates and conditions.
Notes of congratulations were extended to Dmitry Korzenkov for his well-articulated victory in the contest. The discussion also indicated ongoing updates in vehicle models, including new introductions under the Lada name and other AVTOVAZ developments, with additional media access via RuTube for automotive content and reviews. [Citation: Contest recap, automotive history digest]