Is a Porsche/VW flat 4 or six engine a true "boxer engine"?

[Upatdawn]

I mean, the pistons fly away from each other....

surely a "OP" engine is a boxer engine...

https://www.youtube.com/watch?v=JMAEin5iU4Y

[227bhp]

I wouldn't be a very good boxer if I punched myself in the face.

[Upatdawn]

boxers usually face each other and have 2 arms each... and not stand back to back

[HJG]

A 'boxer' engine is an engine whose cylinder banks are at 180deg to each other and opposing cylinders have their own crankpin. Simplify to a 2 cylinder... the crankshaft has 2 crankpins. Left piston is at TDC. Crankpins are so phased such that the right piston is also at TDC. Same story at BDC.

A 'flat' engine has one crankpin for opposing pair of cylinders. Following the example 2 cyl engine, when left piston is at TDC, right piston is at BDC.

Googling a Porsche Boxster crankshaft shows it is a 'boxer' type engine.

An opposed piston engine as shown in your link is a different tyoe of engine altogether and not found in automotive use.

[227bhp]

Upatdawn said:

boxers usually face each other and have 2 arms each... and not stand back to back

Then that would be a Boxers engine.

[stevieturbo]

1st world problems ?

[tapkaJohnD]

Opposed piston = at least two crankshafts.
Or three: https://en.wikipedia.org/wiki/Napier_Deltic

Complicated? See that firing order diagram!
John

[v8250]

stevieturbo said:

1st world problems ?

Definitely. They're all horizontally opposed engines which in my book is great, as I like the World is Flat approach to engine design. I've had VW/Porsche flat4, Porsche flat6 and my favourite, the Subaru flat4. All excellent engines in their own rights and all with quite different designs...but the core principles are the same. Flat and light giving very low CoG and good power output.