In Detroit series 92 and 71, a component is found known as a blower. The full name should be a root blower. Thousands have mistakenly thought that this blower does similar work to a turbo and a supercharger but that is not true.
The function of a root blower in a 2-stroke engine is to direct air to the engine cylinder, without much compression like a turbo or supercharger.
The blower is attached to the air filter so that it can channel the air to each cylinder of the engine.
Another major function of a blower in a 2-stroke engine is to ensure that scavenging takes place. What is a scavenging you may ask? Scavenging is a process in which the leftover exhaust gases are pushed out by newly charged air in order to provide a clean cylinder for the new cycle to begin. Scavenging simply means that all the remnants of the last exhaust gases are forced out through the exhaust valve. This means, the exhaust valve still remains slightly open before the new cycle begins so that scavenging can take place.
No wonder the 2-stroke 71 and 92 series is still regarded as a naturally aspirated engine because the root blower does not play the role of a turbo.
Without a blower, some exhaust gases will still be in the cylinder when the new intake air comes in which will result in incomplete combustion.
So the key major role of a root blower in the 2-stroke engine is to channel air from the atmosphere to the cylinder and to ensure adequate scavenging process in the cylinder.
However, a blower is not needed in a 4-stroke engine because of the availability of an intake valve. The intake valve opens for the air to come into the cylinder just as a blower does. The intake valve also opens slightly at the end of the exhaust stroke, to ensure that air comes into the cylinder to push out the old exhaust gases which is referred to as the scavenging process.
So whether in 2-stroke or 4-stroke, the scavenging process must take place.
You can now see the importance of the blower and its function on Detroit Diesel 2-stroke engines.
Shop blowers, parts and components such as installation kits at ProDieselParts for your 2-stroke engines.