The Gas Exchange Management (GEM) system: DOLMAR is once again setting the standard in exhaust gas emissions

DOLMAR, one of the foremost international manufacturers of power products, takes its environmental responsibilities very seriously and invests heavily in the development of low-emission engine technologies.

So that the air we breathe is cleaner and the natural environment is pro-tected from damage, manufacturers are required to comply to new tougher emission standards. Manufacturers have several options to achieve these new standards including: the use of four-stroke engines with variable valve timing, the deployment of two-stroke engines with sophisticated air intake technology, and the installation of catalytic converters to clean the exhaust gases.

The use of sophisticated air intake technology increases the overall weight of the machine, a significant drawback for portable power tools with smaller engine capacities. In conventional two-stroke engines, the unburnt fuel constituents generate high-temperature exhaust gases. Cleaning these gases with catalytic converters necessitates complicated and costly technical solutions.

DOLMAR is unveiling a new milestone in the development of two-stroke engine technology. As a result of scavenging losses, the exhaust gases from conventional two-stroke engines contain large amounts of unburned fuel. The engineers at DOLMAR have developed an optimized Gas Exchange Management (GEM) system that has succeeded in halving the scavenging losses in the two-stroke engine.

Thanks to the development of this new Gas Exchange Management system, DOLMAR’s engineers are able to use a smaller catalytic converter, which has only minimal impact on the power-to-weight ratio while simultaneously cutting fuel consumption by around 10%.

DOLMAR's new engine technology is destined to establish it as a signature brand within the power products market. The GEM system engine technology developed by DOLMAR is a practical, everyday solution designed for use primarily in portable power products.

In developing present and future generations of gasoline engines, DOLMAR will be harnessing all three options for reducing exhaust gas emissions: the use of four-stroke engines with variable valve timing, the deployment of two-stroke engines with sophisticated air intake technology, and the incorporation of catalytic converters in the exhaust system. Today, DOLMAR already meets all international requirements for exhaust gas emissions by a comfortable margin, with emissions significantly below permitted levels in many cases.