Just how powerful is the explosion during the power stroke?

[superj]

me too

 

[bilbo]

It is an explosion, i.e. "rapid expansion in volume associated with an extremely vigorous outward release of energy, usually with the generation of high temperatures and release of high-pressure gases"

Pinging/knocking is when there are two or more explosions in the one cylinder and the wave fronts meet up
Its why diesels sound the way they do, they have no fixed point like a spark plug where the air/fuel is ignited
It just ignites when compression and heat are high enough and often in more that one spot on the cylinder, so pingy

Its just a small explosion from very little gasoline, not even firecracker strong I would think
But it happens in an enclosed space
Its like the old saying if you hold your hand open and let a fire cracker go off ON your hand it will sting, but if you close your hand around the fire cracker tightly and it goes off you won't be using that hand for a LONG LONG TIME, lol

The diesel's combustion is a lot more rapid and more explosion-like, leading to the unique sound and a pulse-y power output. They do sort of have a fixed ignition point that comes from the spray pattern of the injector. There is no fuel in the cylinder to burn until it's put there by the injector, so it's just hot air. Modern diesels fire multiple shots of fuel if I remember right, a first shot that starts the burn and then some more after that. It spreads out the combustion event and beats things up less.

 

[don4331]

Older diesels really "clattered" at idle, but that was because timing was fixed. New diesels use far more pressure, with variable timing and multiple injection, so don't rattle near as bad.

 

[Bill]

I think you should take out a fuel injector and fire it off with a spark plug next to it and let us know how it works. Be sure to record video and post it here for the rest of us to see.