Automobile engine argument

cambraceres · #1 01-24-2007, 10:26 AM

So I see the auto forum has ceased to exist, but I have a question for any auto buffs around. This morning I got into an argument with an admitted car maniac about the smoothnes inherent in different engine designs.

I contended that an inline 6 is a more smooth running engine than a V8. This person said no, and that a new V8 would run just as smoothly. I ceded this, but then asserted that after wear and tear, a V8 would nor be as smooth running, and that an inline 6 has no such restriction.
After wear, an inline 6 is still perfectly balanced, just because the cylinders are, well, inline. He would not admit this, and not being possessive of the knowledge to competently debate him, I digressed and here I am. So tell me, is an inline 6 an inherently smoother running engine than it's V6 or V8 conterpart(s)? Furthermore, does the wear and tear on a V type engine cause any disturbances in it's smoothness of operation?

I appreciate your help and firmly contend that frankie did it, in the ballroom, totally without asistance from either of the bobsy twins. I mean how short could he possibly be?

Cam

z28dreams · #2 01-24-2007, 10:56 AM

I don't believe a V-type engine would receive any more wear and tear than an inline engine.

I do know that inline (straight) 4 cylinders run very rough relative to other engines.

As far as the bigger engines, wiki says that the big V16's are some of the best balanced engines out there. Adding more pistons doesn't mean that it will run rougher. In fact, I would tend to believe that it will have better balance because you can have more precise control over the firing order.

RunDownHouse · #3 01-24-2007, 11:03 AM

These people may be of more assistance.

gusmahler · #4 01-24-2007, 11:57 AM

Why link to a Honda forum? Link to a BMW forum. BMW forum There's a reason BMW always uses I-6 instead of V6, smoothness. Honda has never used an I-6, AFAIK.

Also see http://en.wikipedia.org/wiki/Straight-6

talentdeficit · #5 01-24-2007, 12:13 PM

i don't know anything about engines, but my physics education leads me to believe a V6 would better distribute the stresses on the engine. it's probably a marginal difference tho.

gusmahler · #6 01-24-2007, 12:20 PM

[ QUOTE ]
i don't know anything about engines, but my physics education leads me to believe a V6 would better distribute the stresses on the engine. it's probably a marginal difference tho.

[/ QUOTE ]

And you would be wrong.

http://www.autozine.org/technical_sc...ne/smooth3.htm

scotchnrocks · #7 01-24-2007, 12:21 PM

Cambraceres,

You are correct. An inline 6 is an inherently balanced design. It also has more main bearings (crankshaft supports) per cylinder than a V8.

guids · #8 01-24-2007, 01:25 PM

[ QUOTE ]
Cambraceres,

You are correct. An inline 6 is an inherently balanced design. It also has more main bearings (crankshaft supports) per cylinder than a V8.

[/ QUOTE ]

This was my thought too, but I dont know if its true exactly. Havin more main bearings will make the car last longer, ie the jeep inline 6 is bullet proof, but that doesnt necassarily mean it will run smother. It really depends on whether the engine is carb/fuel injection, mounts, etc, there are too many factors I think to say one is "smoother" than the other.

cbloom · #9 01-24-2007, 01:27 PM

I don't know much about cars, but it always seemed to me that higher RPM engines feel "smoother" than low RPM (high displacement) engines. Like a Ferrari has a smoother engine than a bored out Camaro or something, on the low RPM engines you can feel the engine surging rhythmically.

scotchnrocks · #10 01-24-2007, 02:36 PM

[ QUOTE ]
[ QUOTE ]
Cambraceres,

You are correct. An inline 6 is an inherently balanced design. It also has more main bearings (crankshaft supports) per cylinder than a V8.

[/ QUOTE ]

This was my thought too, but I dont know if its true exactly. Havin more main bearings will make the car last longer, ie the jeep inline 6 is bullet proof, but that doesnt necassarily mean it will run smother. It really depends on whether the engine is carb/fuel injection, mounts, etc, there are too many factors I think to say one is "smoother" than the other.

[/ QUOTE ]

Didn't mean for it to read like that. The main bearing part was just something unnecessary that I threw in there. The I6 is balanced (and therefore smoother) because of it's natural physics. Think of it as a wheel that doesn't need to be balanced with weights where as a V8 would.