Inline vs. Flat vs. Regular

[Twist]

I know that the Skyline has an inline six and that you can have several other variations of valves (inline, flat and regular). I was wondering what the advangtages and disadvantages of each are. I've only heard of flat design and have no idea of what it really looks like. Inline, from what i've heard, offers a more direct tranferance of power, while the standard design takes up less space. Am I wrong?

[hermunn123]

i assume when you say, regular, you mean V configuration?? inline's are balanced perfectly and dont need counterbalances, same with flats. v's and flats need more room and require twice as many parts=heavier. inlines are the best

[V.S.]

I've always thought V's were the easier to package and cheap alternative, hence their use in many cars(and being refferred to as "regular" by original post). If not, why are V's used in so many vehicles?

[hermunn123]

just because a lot of companies use V's doesnt make them the best. i dont know everything about different configurations. all of the stuff i wrote was off the top of my head. i can find some more stuff out about it. give it a couple hours and we'll have a lot of good replies. maybe texan will show up

[V.S.]

I never said nor implied V was the "best". Just that what you said didn't seem right because there *must* be economic factors(size, weight, and cost) behind a certain engine configuration being so widely used. I'll go further in regard to your post and say that not all types of inline/flats are perfectly balanced.


In response to the original post: Inline is just a straight row of cylinders with the crankshaft at one end. V(what you consider regular?) is two banks of cylinders with less than 180 degrees between them, joining at the crankshaft. Flat is two banks of cylinders on opposite sides of the crankshaft.

If you just imagine a group of cylinders inline as opposed to being in a "V", its easy to see the V will generally be easier to package.



What do you mean by "a more direct transferance of power"?


I feel stupid for not remembering this before I wrote ^.

Just go look at http://www.howstuffworks.com/engine2.htm

[olds88]

what are you refering to as flat??? the head@valvetrain or the way the pistons are positioned in the engine. well any ways way back when the first motors were deemed "flatheads" this was due to the valves being located in the block insted of the heads.later ohv engines became more popular due to the increased flow ability of the valves being directly above the cylander than located off to one side. as the "boxer"or opposed cylander engines go (primaraly used by porche&vw) i couldent tell you if one can get more power than a v or inline. but with the opposed cylander engens it allowed for better air cooling.

[V.S.]

By "flat" I was referring to "boxer" engines. I knew about the possible mis-understanding you brought up, but I figured explaining it to Twist would over-complicate the matter.

[Hudson]

Originally posted by hermunn123
i assume when you say, regular, you mean V configuration?? inline's are balanced perfectly and dont need counterbalances, same with flats. v's and flats need more room and require twice as many parts=heavier. inlines are the best

Okay...there are a few problems here.

Inline engines are not necessarily balanced perfectly. You've never heard of vibrations from four-cylinder? Many inline-fours have counterbalance shafts to deal with this. And straight-eights are notorious for harmonic vibrations.

Theorectically, a "perfectly balanced" engine depends on the number of cylinders. For an "Otto-cycle" (4-stroke) engine, "balance" is achieved by placing the cylinders in banks angled at differing degrees. Fours are best at 180 (flat, horizontally opposed, boxer). Sixes should be at 120-degrees. Eights at 90-degrees. Twelves at 60-degrees.

"VEE" engines are best for their packaging. They are the most compact of the setups. Most companies use this design for engines six-cylinder or larger.

Inline engines take up additional length but are typically narrower than Vee engines. Most odd-cylinder engines use this design, almost all fours, and a few sixes.

Flat engines are quite wide but feature a low center-of-gravity. Old air-cooled Volkswagens and Porsche six-cylinders as well as Subarus and some Lancias used this design. Ferrari used the horizontally-opposed design on some older twelves.

No one design is the best. Each design has its applications.

[Twist]

Thanks for all the info on the engine types. and yes i refer to v as regular. The name escaped me when I was writing. I wnated to know this when I was reading the Road and Track comparison section at the back of every mag. They just labeled some engines I or F (Inline or Flat). I know Porsche and Subaru both use the flat design. And the Skyline GT-R uses an inline configurarition. That was about all I knew. Thanks again.

[hermunn123]

i was thinking of v6's or inline 6's or flat 6's. i just thought he meant 6 cylinders for some odd reason.

[Hudson]

Originally posted by hermunn123
i was thinking of v6's or inline 6's or flat 6's. i just thought he meant 6 cylinders for some odd reason.

But Inline is not necessarily the best format for sixes. V6s are usually lighter and almost always more compact, for example.

[hermunn123]

how can V6's be lighter?? they require more parts, therefore more weight.

[Hudson]

More parts...like camshafts (in the case of OHC engines) and heads? Doesn't an inline engine require a LONGER camshaft or head than a Vee? Vee engines typically use less block material than an inline engine. Intake and exhaust manifolds are more compact (typically).

[TheMan5952]

I have a Slant 6 all it is, is a I-6 tilted over 30 degrees.

It allows the Intake manifold to have a Ram effect because of the long runners, and it allows Good under hood room.

[hermunn123]

you're so smart Hudson. BTW, do you want all your old car magazines??