Traverse 4 VS Vtwin

[Rickrod3]

I'm curious as to what others think objectively about the benefits of the Traverse 4 over the Vtwin?

Vice versa what are the benefits of the Vtwin over the 4?

Rick

[Ivan]

L4 engine actually makes a bit of sense, is fairly easy to balance and can make decent power from a square cylinder. Its also about the simplest form of four stroke engine that can be built, multi-cylinder wise. V2, V4, V6 etc. all add a bunch of complexity in balancing and engineering.

V Twins will keep you fitting in with the whole cruiser crowd quite nicely. Anyone who doesn't know a thing about engine theory will give you more money at resale time, since they think it looks cool and gives you "that sound" that an inline 4 could never give. The trend in today's motorcycle thinking is toward long stroke, high cylinder volume engines, which make great torque, lots of noise, and in the vtwin config are terribly unbalanced. Like I said, some guys like that. Last few times I saw the dyno run, on the V twins, they only said torque numbers, since they are so grossly over stroked the HP numbers make them sound funny in the presence of scoots like BMWs and The sport tourers like them. 248 ft-lbs sounds great until you add in that 43 bhp number.

I am certain there will be proponents to the Vtwin that will jump in here, so, I won't belabor the point any farther.

[crazy steve]

All depends on what you want the bike to do or your intended use, and how much money you want to spend.

As Ivan said, the I4s are much smoother and can make huge horsepower at the top of the tach, usually at the cost of not so great low end power. Usually more hi-tech stuff involved, so for the home mechanic it can be complicated. OH cams, multiple carbs, just more stuff to keep track of.

A stock V-twin will make most of it's power down low, so if you're just 'cruisin', there's a lot less shifting needed. The motors are narrower which will generally make the bike more nimble at slower speeds, all else being equal. The pushrods motors are extremely simple, so can be pretty easy to work on. Most have single carbs, so no carb syncs needed. Usually better fuel economy.

Biggest advantage of the V-twins? Much deeper parts well. Even with the 'clones', there's a lot of custom/aftermarket parts out there and if you're talking Harley, it's nearly unlimited. It's pretty easy to make big power too, if you're willing to spend some money. Lack of parts is the bane of any XS owners existence.

The XS11 is a bit of an anomoly among I4-powered bikes, as it's type of wide, smooth powerband isn't seen much anymore. I own a couple of Sportsters, and my '93 (with upgraded suspension and 85 RWHP) is my favorite for around town/handling twisties. The bigger Harleys are generally pigs when it comes to handling, and I'll include most of the clones in that catagory. If the XS had a 30-years newer frame/suspension/brakes, it could be the equal of any of the newer bikes....

My .02

'78E original owner

[Larrym]

Sopwith Camel? Biplanes???

I've never been able to look at a V-twin and not see it as missing something: the extra cylinders. What I mean is that to me, the V-twins are only part of a complete and true radial engine. You know, like the ones used on old WW1 airplanes where the cylinders continued around to make a complete circle.

The advantage of a radial engine was that the opposing pistons and hardware tended to balance out the weight and provide a power stroke. Makes for a smoother, less vibration, higher rpm capability.

Current v-twins do have the counterbalances on the crankshaft but that's just dead weight. Also the counterbalances work to oppose the outward/inward motions and stress of the large pistons when they are at TDC/BDC. When these weights are at 90 degrees to the axis of the stroke they do just as much work to make the engine vibrate back and forth.

Just doesn't seem condusive to long engine life at anything above idle speeds.

Contact???


CONTACT!!!!

Pulls the propeller down HARD and steps to the side.....

[fredintoon]

I'm curious as to what others think objectively about the benefits of the Traverse 4 over the Vtwin?
Vice versa what are the benefits of the Vtwin over the 4?
Rick

Hi Rick,
it's all in the timing. Or the balancing. OK, both.
Let's start with a single. No effin' way you can balance a single.
Vertical twin? 360º twin is just as unbalanceable as a single. 180º twin has perfect primary balance but a horrible rocking couple.
Put two 180º twins end to end and you have perfect primary balance and the rocking couples cancel each other out. Your classic in-line 4.
V engines:- The narrower the angle the closer it gets to an unbalaceable single. Thus a 45º V-twin vibrates like a paint-shaker while a 90º V-twin has perfect primary balance. Regardless of cylinder angle, V-twins have little or no rocking couple.
Straight 4 is balanced and has twice as many power pulses as a V-twin.
Some V-twins are balanced better than others.
For engines of equal complexity, twice as many cylinders means twice as many parts to wear out.

[Rickrod3]

Hey Guys:

thanks I find this all very interesting.
I hope more will chime in.

Great reading thanks again

[motorhead]

It's all in intendid purpose .V-twins are inherently shakey .Big heavy pistons on Long Strokes =big torque,big shake.4 little holes with short stroke =limited torque but smooth reving .I have both and they both have a spot in my garage.I don't think they can balance a v twin without some kind of seperate balancing shaft.BUT OH man the torque .thump-a thump-a.

[fredintoon]

- - - I don't think they can balance a v twin without some kind of separate balancing shaft.BUT OH man the torque .thump-a thump-a.

Hi motorhead,
V-twins can have perfect primary balance but ONLY if the cylinders are at a 90º angle. See Moto-Guzzi or Ducati.
BUT there's a price; the firing interval:-
Thumpa-thumpa-wait for it-thumpa-thumpa-wait for it and so on.
Then there's 90º rephased vertical twins and whatever fancy term the sales guys dreamed up for two 90º rephased twins joined end to end.

[Larrym]

Right Said Fred!

Thanks for pointing that out, Fredintoon. Like I said before, the 45 degree twins look like they're missing those other cylinders. I forgot about that "wait for it" between power strokes. Personally, I found that awkward pause between firings to be discordant: Like hitting two keys on a piano which are right next to each other or scraping one's fingernails on a blackboard.

I guess some of the owners of these engines feel the same way because I've witnessed them revving them up at stoplights. The faster the engine fires the shorter that "sound of one hand clapping" becomes. But it never really goes away no matter how high the rpms are.

That puts things back to where we were before: the higher the rpms the more the motor shakes in an effort to tear itself apart. A lot of "sound and fury" that doesn't transfer where the rubber meets the road.

They just don't have the strong "Kung-Fu" of an inline 4. Doesn't mean that folks won't like them however. But that's a marketing/consumer preference issue.

[motorhead]

I guess some of the owners of these engines feel the same way because I've witnessed them revving them up at stoplights. The faster the engine fires the shorter that "sound of one hand clapping" becomes. But it never really goes away no matter how high the rpms are.

.

Interesting observation/statement.So the v-twin riders rev their motor to pull the "claps" closer together .What's the reason others rev their motors.

[fredintoon]

And around they go - - -

I've never been able to look at a V-twin and not see it as missing something: the extra cylinders. What I mean is that to me, the V-twins are only part of a complete and true radial engine. You know, like the ones used on old WW1 airplanes where the cylinders continued around to make a complete circle.

The advantage of a radial engine was that the opposing pistons and hardware tended to balance out the weight and provide a power stroke. Makes for a smoother, less vibration, higher rpm capability.
Contact???
CONTACT!!!!
Pulls the propeller down HARD and steps to the side.....

Hi Larry,
The Sopwith Camel engine, along with the engine in the Spad, the Fokker DR1 and many another WW1 airplane was not a radial, it was a rotary. The cylinders went round with the propeller.
Radial engines came later. The radial layout lends itself to air cooling and was the first choice for carrier-borne aircraft because it was short, allowing a carrier to pack more 'planes on board.
The narrow angle V-twin engine was first used in motorcycles because that cylinder configuration was a good fit in the upgraded bicycle frame of those days.
The different cylinder configurations were used to meet the engines space requirements; the balancing, or the lack of it, was a thing you lived with.

[Ivan]

Larry, the radial engine was never known for balance. they had single throw cranks. If two pistons on a single throw crank are bad, think of 7, 9 or even double that in twin bank engines. The whole ring of pistons moved as one mass and they shook like a wet dog. Now on the beloved Camel and some other early WWI fighters, the crank was actually mounted to the frame and the whole engine spun, cylinders and all. The thought was to keep it cool, and was later found to be unnecessary. The engines that spun had no throttle, just an ignition switch. So that's why the old movies of those airplanes landing had a brap...brap.....brap..brap......brap sound, since the pilot was flipping the ignition switch on and off. Since the pistons on those stayed fairly stationary, they were very smooth. Well, according to my Grand father that flew a couple like that waaaaay back in the day.

[Larrym]

Ear of the Beholder

Motorhead,

".What's the reason others rev their motors?"

I've never asked them why. I've worked on a few v-twins and v-fours for others when the official "mechanics" have thrown in the towel. After getting them running and "tuned" I've revved them a bit to check them out and listen for any problems. After that I don't rev them up anymore. Same practice applied to all the bikes I've owned myself. Just not an interest of mine I guess.

Some have started the bikes and then after taking them for a test drive, they've come back and revved them. Unclear whether they did it for themselves or to show me.

Fredintoon,

So I missed the right engine by an entire world war?? That's within my usual margin of error.

The history of motorcycles' origin is fascinating. The idea of a two-wheeled engine powered vehicle was certainly worth striving for by any and all means available at the time.


But back to the transverse 4 vs the v-twin comparison, I'm still looking at the two with an eye for measurable differences like: (MTBF) Mean Time Between Failures, (MTTR) Mean Time To Repair, (MCTR) Mean Cost To Repair, Mean Engine Lifespan, Total Overall Downtime, etc. ad Nauseum...

That's cause I'm more of a mechanic/technician than a driver/rider. From that perspective I'd predict that a comparison between the two types of motors would show a wide difference in the numbers.

[Larrym]

Showtime!!

Note to Self:

Take my XS1100 to an air show this upcoming year.


I just gotta see more airplane engines in operation in real world/real time.


Thanks Ivan!!

[motorhead]

larrym
I think you're grasping at straws if you think the inline 4 will be superior in any of your "mean time " evaluations.Where it is superior is performance .I really don't think with todays tech you're going to find a v-twin less reliable.You know it will take longer to repair an overhead cam 4 since there are more pieces. Probably cost more to repair the 4.Four probably has more down time ..As antiquated as the initial design is of the v-twin ,I'll bet hard cash they hold up as well or better than the four.
And I appreciate an experienced tech as you must be .I am 55 and built my first multi cylinder motor at 15.I can diagnose circles around most.Not bragging .Just sayin