Flat engine vs Boxer: Here's the Difference 

I'm surprised to read the comments and see that people aren't understanding the video, so I'll try to help. A flat engine is simpler than boxer, then i'll start from it. A flat engine is just a engine has the pistons turned sideways (on 180°), but it usually has fewer crank pins, which means that the opposing pistons need to share the same crank pin, as a result, they work in opposition. Explaining this: When the crankshaft crank moves back from left to right, the left piston is extending (because it is in combustion/explosion) and the right one retreating (expelling gases and compressing air inside the chamber in the engine). Note that this always results in complementary movements, as the two opposing pistons are moving the engine block to the right during combustion in the left piston (because it will stretch to the right while the other piston retreats to the right too). And then, the block will be forced to the left direction when the right piston combusts and all the opposite movement occurs. This variation in movement in the engine block is what we call vibration, as it throws the engine from one side to the other, which can misalign something depending on its intensity. A boxer engine just works with more crank pins than a common flat engine, which allows the pistons that are in opposition to be able to compress the air inside the engine or carry out combustion/explosion at the same time. That is, they are working in a mirrored manner. That's why the boxer engine vibrates less, after all there are fewer movements in similar directions happening at the same time, since the pistons are always pulling or pushing the crankshaft in the opposite direction with the same force and at the same time (mirrored). With that, I think you can now conclude what the video tried to explain: A boxer engine is an improvement on the flat engine, and a beautiful improvement at that by the way. I hope I helped and didn't cause any more doubts :D

I found this video confusing. Not very good.

It would be better if you could have a side-by-side comparison of Flat engine vs Boxer motion in the video.

I’m more confused now than I was before I watching this video about which is flat and which is boxer. So flat is when the pistons mirror each other on the same pin on the crank shaft?

The thumbnail showed all that was needed

180° Flat 4 OHV Engine

The video is very good and crystal clear for me, but I am a mechanical engineer. People that are not close to engineering environment is rational to find it a bit confusing

You need to get you facts straight about Porsche engines. They are ALL boxer engines!!!

As long as a flat engine is defined when a pair of pistons use the same crank pin, while a pair of pistons of a boxer engine use different crank pins, they are different by definition. But why do you say that a boxer engine is a flat engine?

This is BS, take a Kinematics course

I speak 5 languages and still dont understand :O

This gets some information correct - but complicates it with _a lot_ of incorrect information, unfounded claims, confusing animations, and poor images. "Having a more flattened and tall shape...", re. engine location within vehicle. "The engine will drop down the passenger compartment, rather crushing into it." re. flat engines are supposedly safer. "... known, due to their configuration, to have a better power transmission from the engine, and better fuel economy." No, they are not known for better power or economy - because it isn't true. Does not resemble a real boxer punching. We are not having more boxer engines - the number of companies making flat engines has dropped by ⅔ in the last 50 yrs. No, it doesn't dramatically reduce vibrations or cancels out forces. WTF is that fantasy nonsense at 01:51 ? 😂

This didn't explain anything 😂

Nah it's a boxer. It just doesn't sound like a boxer on idle