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Vehicle: Motorcycle: Engine
Harley Davidson V8   (+9, -6)  [vote for, against]
Radial configuration (and no, the word "radial" is not a typo for "radical")

V8s are undoubtebly the stongest and badest sounding engines available for cars. But almost any true motorcycle enthusiast would tell you that there is no better sounding engine than the V-twin in Harley Davidsons. Well it turns out that the V-twins in Hogs work differently than convensional V-2s. It is a radial type engine, meaning that there is only one true crank on the crankshaft, and all cylinders pivot and such (I know that my description is lacking, see link). Well I say why not combine the best of both worlds? Picture 4 Harley engines mounted one by one behind eachother, except that each cylinder plane is fixed together so that it maintaines the same firing order as a Harley engine, and when one cylinder fires, the other 3 on that side do as well. Sure it wouldn't be at all smooth or ideal for cruising, but it sure would sound bad as hell.
-- acurafan07, Jun 11 2007

Howstuffworks... http://science.hows.../radial-engine3.htm
I know it isn't an ideal link, but it's the only thing I could find to describe what I'm talking about. [acurafan07, Jun 11 2007]

Boss Hoss http://www.bosshoss...ike.asp?x=BHC3ZZ4SS
V-8 motorcycle [bleh, Jun 11 2007]

Bugatti W16 Quad Turbo http://www.supercars.net/cars/3190.html
possibly the gaudiest engine ever created [CaptainClapper, Jun 11 2007]

Fueling W3 http://thekneeslide.../03/31/jim-feuling/
Jim Fueling's method for increasing displacement [discontinuuity, Jun 11 2007]

Shaking forces of twin engines http://www.dinamoto...%20motors/twin.html
Good explination of vibration and balancing in V-twin engines [discontinuuity, Jun 11 2007]

Amazonas...wow... http://www.horizons...ws/2000-11-06.shtml
I love the crazy machines people build...but then again, I'm a Moto Guzzi guy. [normzone, Jun 15 2007]

Radial moto http://images.googl...Den%26safe%3Dactive
Take that, Harley! [elhigh, Jun 19 2007]

Radial the other way! http://images.googl...Den%26safe%3Dactive
Looks like it uses a variator primary [elhigh, Jun 19 2007]

Harley V-Quad http://thekneeslide...-4-cylinder-engine/
V-4 made of Harley parts [discontinuuity, Jul 20 2007]

Shovelhead V8 Photo http://i282.photobu...08/ShovelheadV8.jpg
Here's my depiction of a Shovelhead V8...best to fire the front cylinders together, and the rears together for full audio effect! [BLIGHT, Sep 18 2009]

Truly OCD collection of v-twin cylinder angles http://en.wikipedia.../wiki/V-twin_engine
[not_morrison_rm, Apr 14 2013]

So basically you want a V8 with a crankshaft that only has four crank throws, each of which has two connecting rods. Should work fine. I think most flat sixes or eights (or more) have a similar configuration. One problem is bearings. With a throw wide enough for two connecting rods the distance between main bearings is going to be greater. Not sure if that will be an issue or not.
-- Galbinus_Caeli, Jun 11 2007


Actually, wait a second.

Most V8s that i have had apart only have four throws. Each 90 degrees apart. Two opposite pistons share each throw.

So are you putting all the throws the same direction off the shaft? So that all the pistons on one side are at TDC at the same time, then all the ones on the opposite side 90 degrees later? And you are going to fire all the pistons at the same time?

Yeah, that is going to sound bad ass. Or at least bad. Well, loud. And it is going to vibrate like crazy. And you are going to have to have ONE HELL of a set of counterweights on that crankshaft.

But Ok, sounds interesting.
-- Galbinus_Caeli, Jun 11 2007


Well, it was just a thought... Never said it was practical.
-- acurafan07, Jun 11 2007


Hey, I bunned the idea. I do think it would make an interesting sounding engine.
-- Galbinus_Caeli, Jun 11 2007


"V8s are undoubtebly the stongest and badest sounding engines available for cars." I doubt that...
-- BJS, Jun 11 2007


"the stongest"

Well since "stong" is a measure of relatedness to a Chevrolet 302, I think this is a valid statement.
-- Galbinus_Caeli, Jun 11 2007


I can't go along with anything that's going to make those machines or the people that ride them any more obnoxious.
-- Noexit, Jun 11 2007


bun for the crazy idea... but I must [link] to the W16 Quad turbo, in terms of "strongest." (but secretly I do agree, Galb)
-- CaptainClapper, Jun 11 2007


Harley V-twins have an angle of 45 degrees between the cylinders, which creates lots of vibration but allows for better smoothness of power delivery and ease of packaging.

Almost all V8s have a 90 degree angle between the cylinders, which almost completely eliminates vibration with the proper counterweights. Since V8s have four times the cylinders of a V twin, they have much smoother power delivery, so a narrow angle isn't needed.

It would be possible to build a V8 like this, but I think it would be more trouble than it is worth, since you would have to custom make the whole bottom end and probably move the whole valvetrain around. Otherwise the engine would be much too long.

You might have more success making a five-cylinder radial out of Harley parts, like the Fueling W3 (see link).
-- discontinuuity, Jun 11 2007


F1 techs have come to the conclusion that V10's can get the most hp/l out of piston engines.
-- Giblet, Jun 12 2007


For a prescribed capacity, a prescribed fuel, and various other constraints, yes.
-- Texticle, Jun 12 2007


Maybe V10s make the most HP per liter, but not torque I bet. And torque is the real strength.
-- acurafan07, Jun 12 2007


Great. An engine 4 times as unreliable and noisy as a normal Harley v-twin. Just what the world needs.
-- Murdoch, Jun 12 2007


Well 4 times as noisy can be solved with a good muffler, and just because it has 4 times the cylinders doesn't make it 4 times as unreliable.
-- acurafan07, Jun 12 2007


"PoTATATAto, PoTATATAto, PoTATATAto!"

Hell, I'll bun it just to hear that once in real life. That'd be weird funny cool.
-- elhigh, Jun 12 2007


[Giblet], I think F1 V10's are more about the shape of the space available for an engine in a F1 car than anything else, i.e. a fine compromise between length, frontal area, weight distribution, etc.

Generally, V-engines with common crankpins develop their best balance characteristics when the V angle is 720/(number of cylinders). In the case of a V8 that is 90deg. In the case of a V4 it's 180deg, that is, a flat-four. Traditionally, V12s have had 60deg V angles, and V16s 45deg. All these instances bear out the principle in practice. I think Lancia experimented with a 120deg V6 at one time, but I speak under correction. In either event I believe the narrow-angle Lancia V4s used staggered crankpins to mitigate imbalance problems, as do the VW VR engines and Honda motorbike V-twins.

So, eight Harley Davidson V-twins in a row would make an extremely bulky but well-balanced V16. Because it would be a quite emphatically non-wonky engine it would have a disappointingly smooth sound, however.

Speaking of "potato potato", [Elhigh], have you heard of the Amazonas motorcycle that used to be manufactured in Brazil? It had a 1600cc VW Beetle engine. We all know what those sound like: "spud spud spud spud..."

[+], btw, because the V8 would be a wonderfully Edwardian blunt instrument of a thing.
-- Ned_Ludd, Jun 15 2007


Are you sure they'd make a well balanced V16? Seems like the more cylinders you'd have firing at once would make it worse than a V8, but I'm probably missing something.
-- acurafan07, Jun 15 2007


I AM familiar with the Amazonas. Gargantuan.

Gotta admire that they used the entire drivetrain, including reverse gear. They welded the diff and stuck a sprocket on one side.

I saved an issue of Motorcyclist magazine for several years solely on the strength of the Amazonas review. Then, further in the same issue, the reviewers went to their local Vdub shop and bought some go-faster bits for the Amazonas. It all fit, it all worked, and the thing went from anemic and farty to robust and commanding. Replaced the original clutch with one from a bus.
-- elhigh, Jun 15 2007


Yes, this might work as a V12 or something, but it would definately be more trouble than it's worth. Harley engines have the pushrods on the front, while V8s have pushrods in the "valley," so the engine would end up too long if you just put the engines end to end.
-- discontinuuity, Jun 18 2007


Well it could even be an overhead cam for all it matters. The Harley part is the radial configuration, not every aspect of the Harley V-twin itself.
-- acurafan07, Jun 18 2007


So just a 45 degree V8 with common crank pins? I guess you could do that. It would make quite a lot of noise and vibration, but that's probably what you're going for. Ford had a 60 degree V8 in the Taurus SHO, so I guess any angle is feasable, although not always the best.
-- discontinuuity, Jun 18 2007


True that odd angles aren't always the best, but in the Taurus' case, I've heard the old SHO motors perform and I'm probably not the first to note that they sound pretty good (especially considering their relatively small 3.4L displacement). I'll try to find a link for a sound clip.
-- acurafan07, Jun 18 2007


I'd suspect the SHO's crankpins are staggered 30deg to emulate 90deg V8 firing. Either that or it's a single-plane.

A 45deg V16 will be well-balanced when the crank throws are 45deg apart.

Another way of doing an 16-cylinder Harley-Davidson engine would be four "fans" of four cylinders each. The observant would notice that that would produce a conventional two-plane V8 crank configuration, with a 45deg V-twin (i.e. Harley linked big-end) in place of each cylinder. No idea what that would sound like, though.
-- Ned_Ludd, Jun 18 2007


So a W16 like in the Bugatti? Sounds cool. I think the Bugatti has 15 degrees between the cylinders in each bank, if it is based on the Volkswagen VR6
-- discontinuuity, Jun 18 2007


Ain't this article supposed to be in Car&Driver Mag.?
-- Macdaddyx1, Feb 10 2008


No.
-- Ned_Ludd, Feb 11 2008


Hey guys, this is an old thread, but still an interesting idea, making a V8 out of motorcycle engines. The Hayabusa V8 is a very nice product indeed! I don't think a pushrod Harley V8 is all that viable, but it's certainly more than a half-baked idea. it would be best to fire all the front cylinders together and then the rears all together for full audio effect. I posted a link to a Photoshop Shovelhead V8 above. Be fun on a sand rail or vintage drag-bike... Cheers, BLIGHT
-- BLIGHT, Sep 18 2009


Use a turbine
-- sninctown, Sep 18 2009


Just slipping a Chev or Ford V8 in a Harley is fast and loud.

It's called a Boss Hoss.
-- whlanteigne, Apr 14 2013


wikipedia has a list of all the cylinder angles for v-twins from 20°(Daimler) to 170°(Zündapp). C link.

//is fast and loud. Pulse jet motorbike, and it saves all that faffing around with pistons and so on.
-- not_morrison_rm, Apr 14 2013


Going on a ride today on a Harley. Can not wait. The sound of the engine is partly what makes it so wonderful. Yay for the Harley. (just saying).
-- blissmiss, Apr 14 2013



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