What's the difference in engine layout?

[redrims]

Not sure how to ask the question, but what the difference between V (as in V6 or V8), Inline (as in Inline 6), Flat (as in Flat 6), and Boxter engine (like the horizontally layed WRX boxter engine. Is it that just the name of the engine?).

What are the differences between V6 and Inline 6, etc...? My friend got flamed by a bunch of other guys cause he said the Supra was a V6 instead a Inline 6. I just want to know the difference between these and advantages/disadvantages.

[funkdaddysmack]

See how 4 cylinder engines are laid out? That's inline... In that all of the cylinders are 'in a line'.

V6, V8, there are separate engine banks. If you look at it from the front of the block, you'll see two banks of cylinders arranged in a V-shape. (3 or 4 cylinders on each 'bank')

The flat-six design used by porsche and subaru, also sometimes refered to as horizontally opposed, is two banks of cylinders laid horizontal, as opposed as our engines that have the cylinders running vertically.

The supra engine is a inline 6, so all of the cylinders are in a line, just like our 4 cylinder engines. It just makes the block longer to fit the extra two cylinders.

Inline 4:


V8 (Note the V shape, the two banks of cylinders):

[redrims]

What about the Flat 6 as in Porche? How are these arranged.



Will you get more hp/torque from the way a motor is layed out?

[JJB]

(disclaimer, the stuff here is off the top of my head and might not all be correct, I am sure others will be glad to point out any misinformation).

images taken from HowStuff works.com

V-6:

you can see the that pairs of cylinders form a V-shape. In most cases the angle is around 90 degress (I think). In the case of the VW engines they have a "narrow-angle" V6 where the angle is considerably less than 90 degrees.

Of note is that both V6 engines and V8 engines are not harmonically balanced. They need some other mechanism (shafts, weights) to keep them nicely balanced as they run. A V-12 is a naturally balanced engine and runs very smoothly.


Flat 4:

This configuration is also know as the boxer engine (like in subarus). For a flat 6 add two more cylinders. This style of engine can basically be viewed as a 180 degree V engine. No four cyclinders are naturally balanced.

These flat engines were very popular in the aircraft industry. As a matter of fact, the flat 4 in the Subarus (Fuji Heavy motors) can trace it's ancestry to being in the nose of Zeros.

Inline-4:

Of course you can add two more and then you have an in-line 6 cylinder. In many cases front wheel drivers are mounted traversly (versus longitudonally) and the cylinders are lined up from left to right. Most straight sixes (RWD) are line dup so that the cylinders are front to back.

In the case of the straight-6 it is the other type of naturally balanced engine. This is why most BMWs have such a smooth motor!

A second note on straight engines. The cylinders are sometimes (like in the old Jeep wagoneers) not perpendicular, but all are mounted at a slight angle with respect to the rest of the car. In those cases they are refered to as a slant 6.

[JJB]

looks like FunkDaddy was posting at the same time I was

[funkdaddysmack]

Originally posted by redrims
What about the Flat 6 as in Porche? How are these arranged.



Will you get more hp/torque from the way a motor is layed out?

Sorry, I was editing my post, I descibe the flat-6 in my above post.

I'm really not sure the advantages/disadvantages of each engine design. It seems like the V6s and V8s usually have a higer tq/hp ratio than an inline or flat designed engine. But I could be completely wrong, too

[funkdaddysmack]

Originally posted by JJB
looks like FunkDaddy was posting at the same time I was

This is getting crazy!

Damn, you found ALL the cool pics... stupid google images! hehehe

[redrims]

Thanks!