engines
There are many internal combustion engines powered by gasoline, diesel, propane, or natural gas; hybrid vehicles, plug-in hybrids, hydrogen-powered fuel cell vehicles, and all-electric vehicles. Fuel-powered vehicles have an advantage due to their limited range and high battery costs. Some options require a network of refueling or charging stations.
Thermal gaps in the valve mechanism are used to ensure a hermetic fit of the valve on the seat, when the parts of the valve drive expand during engine operation