When a Jacobs internal engine compression brake is actuated, at what point is cylinder compression dumped into the exhaust circuit?

Question

Quizplus · Accepted Answer

The Jacobs internal engine compression brake, commonly known as a Jake Brake, dumps cylinder compression into the exhaust circuit around Top Dead Center (TDC) on the compression stroke. This action effectively converts the engine's power-producing expansions into a power-absorbing air compressor, slowing the vehicle.

When a Jacobs Internal Engine Compression Brake Is Actuated, at What