A valve arrangement in the cylinder head where the valves are at an angle to the cylinder bore. Canting the valves can make for a straighter path for air to flow into and out of the intake and exhaust ports. The area of an engine in which the air/fuel mixture is burnt.
There are lighters out there designed to burn up to 2500 degrees Celsius, so it is certainly possible to find one that is up to the task if you have a project that involves melting glass. One reason that most lighters will not melt glass is that they are simply not hot enough.
So how hot does it really need to be in order to do this, and what type of lighter would you have to use? The average melting point of glass is somewhere around 1500 degrees Celsius. This is certainly hotter than most lighters get, and it would take quite a bit of time to heat the glass to this point. If you are looking to melt glass, however, you will find that you have to choose lighters that can offer a sustained flame that burns at a very high temperature.