[nicholastanguma]

SS Cycle used to make a 60 degree v-twin crate engine, and Sputhe used to make a 60 degree v-twin crate engine, both without balance shafts and both of single crankpin design. Both companies claimed their engines were noticeably smoother in operation than Harley-Davidson v-twins.

So, then, imagine two Sportster engines of exactly equal bore/stroke, compression, timing, fueling, single crankpin design, absolutely everything...

...except degrees of separation between the cylinders. Imagine one engine was the traditional 45 degrees, and the other was 60 degrees.

Would the 60 degree Sportster mill actually produce less vibration to the point it's an undeniably better engine? You know, less rider fatigue, less mechanical fatigue, more hp potential, etc.

[GlennF]

A 45 degree V twin is not that much different to a parallel twin really.

Note that the Harley Davidson V-Rod was a 60 degree twin.

[Carl Fenn]

I can’t really comment on that only ever owned parallel twins or fours.

[AzCal Retred]

"Ducati - the Thinking Man's Harley..." 

https://www.motorcyclistonline.com/1978-ducati-900-gts-thinking-mans-harley/

[Karl Childers]

Modern Harley V twins are either rubber mounted as in the touring line or the engine is counter balanced and solid mounted for the Softails. Both systems lets them get away with their traditional engine configuration without a lot of vibration reaching the rider

[axman88]

Why stop at 60 degrees, when there are plenty of examples of single pin designs with other angles, up to 180 degrees?

I think that Fabio Taglioni's  90 degree V, or "L Twin, as Ducati preferred to call it, was an outstanding example. https://www.wikiwand.com/en/Ducati_L-twin_engine

But, there's lot lots more to consider, like how engine space requirements will constrain the overall design, intake and exhaust configuration, and manufacturing cost considerations such as whether parts can be shared between front and rear ( left and right for transverse mounted V's ) cylinders.

Maybe a more easily resolved comparison would be to compare single pin designs with dual pin?  45 degree 1100 cc engines were put into Honda Shadows that are comparable in all respects except crank pin count.  https://en.wikipedia.org/wiki/Honda_VT1100

Also, there are lots of parallel twin engine configurations to consider.  https://motorcyclemojo.com/2014/09/crankshafts-and-firing-orders/

One can explore primary vibration of different configurations for themselves using 3D modeling software that allows dynamic simulation.  Solidworks will do this.  I don't know if there is any free software available that does this, but I wouldn't be surprised if there was.

[cyrusb]

I have lived with quite a few Harleys and Ducatis and have found its all about the balance factor. The Ducs were almost always very well balanced right out the factory. I had a 750 that was almost a turbine!
 The Harley Sportsers I had were another thing. Hit or miss balance wise. However I had a super vibrating 77XLH that I had a very expensive dynamic balancing act done on and after it was almost as smooth as a Ducati L twin. I have to add that I got this bike cheap because it vibrated so bad at 40 mph  you developed double vision. Do any of these balance magicians still exist? My guy was a 70 year old cigar chewing Garfield NJ basement shop dweller. Here is a shot of 2 well balanced machines.

[gizzo]

"Ducati - the Thinking Man's Harley..." 

https://www.motorcyclistonline.com/1978-ducati-900-gts-thinking-mans-harley/

I object to that on a couple of levels :that they assume I'm a thinking person, and that they compare my bike of choice with a Harley 😂

[GlennF]

The Guzzi V7's are also a 90 degree V Twin.

I suppose you could call teh old BMW Boxers and the Ural's a 180 degree V Twin whereas the Bonneville would be a 0 degree V twin.

[axman88]

Folks might be interested in reading this article that discusses some of the elements of engine primary balance, cylinder Vee angle, crankpin locations, and more.  The author talks about why Sportsters shake in the way they do, why original Ducatis had a long wheelbase, why some manufacturers choose angles other than 45 or 90 degrees, and much, much more.

https://www.cycleworld.com/2016/02/01/motorcycle-v-twin-and-parallel-twin-and-flat-twin-engine-tech-sound-insights/

I would find it interesting to see a list of machine engines with Vee angle, crankpin angle, and whether or not a balancer shaft is incorporated, but this sort of information can be laborious to compile.  I find myself searching for pictures of replacement cranks to figure out crankpin angle, because that number doesn't generally appear on any spec. sheet.  All of the machines I currently ride use a single crankpin design, including a Honda Shadow 1100 ACE from the mid 90's that, according to the folk history, caught Harley's attention and prompted them to file their "Potato, potato" lawsuit to copywrite the single crankpin, 45 degree engine sound.   Harley's copywrite attempt failed.

What I find remarkable about this Honda 1100 ACE engine, is that, prior to 1995, all Honda 1100 engines had dual crankpins.  When they switched to single crankpin, Honda retained a 3 disc forged crankshaft.  There was no practical design or manufacturing reason for them to make the change, it was 100% marketing driven.  To achieve the american iron styled "loping idle" and "rumbling" sound, Honda gave up 10 horsepower, and 10 ft-lbs of torque, and PAID development money to do this.  Despite the increased vibration, or maybe because of it, USA riders bought these machines, (which were built in Honda's factory in Ohio), by the carload, they were very popular.  Which just goes to prove, better is, as better SELLS!   After around 1998, some models of VT1100s were sold with single crankpin, while others were built with dual crankpin.

[axman88]

A couple more links that might be of interest to folks reading this thread:

The "Tractor and Construction plant Wiki", of all places, includes a list of moto engines with various cylinder angles, 20 different angles included from 26 to 170 degrees.  I see the Honda Vee twins seem underrepresented.    https://tractors.fandom.com/wiki/V-twin_engine

This page shows the shaking force equations and presents animated models of various configurations   http://sense.net//~blaine/twin/twin.html

The models look like Mathcad.  I wonder if that is still around?

[AzCal Retred]

These are all great links, and if "Folks" actually wanted to bootstrap hisself into more knowledge, "Folks" would really study on them. Maybe then "Folks" would start pre-screening some of their questions, perhaps prefacing them with "X and Y say this about topic "Z", but I'm not quite making the full connection yet..." That would denote educational progress, not boredom.
Physics & Chemistry are pretty well sorted out by now. It does however take a small box of mathematical skill to fully benefit from the knowledge. "Apply what you know to figure out what you don't"

Those Honda examples are great, if ever there was a mechanical engineering based company, they're it. In the wayback they were using torsion bars for valve springs on the mass production, venerable old CB450 "Black Bomber". The NS500 was artwork, and of course the multi cylinder GP efforts of the 1960's.

[Karl Childers]

The NS500 was artwork,

Oval pistons if I recall right.

[GlennF]

Way back in the 70's I started an engineering degree (which I dropped out of half way through to pursue a "more interesting lifestyle" for a while and never went back) and we spent a lot of time on (very expensive) analogue computers modelling this sort of stuff using differential equations.  There are no algorithms or code in an analogue computer you patch in modules that are integrators and differentiators and set variables with potentiometers. Not a keyboard to be seen.

This is an analogue computer:

[cyrusb]

So, the answer to the original question is?
 My take is all configurations can be well balanced.
 The quality of the balance is important. Imperical/stactic methods have limits.
 An unbalanced engine will always make less power than a well balanced one.
 The 45 degree angle with Harleys ignition timing approaches the power impulses of a large single. Take a sporty on a dirt road and goose it. It will leave a dotted line. Very helpful in dirt oval competitions, as it allows the tire to rebite.

[axman88]

So, the answer to the original question is?
 My take is all configurations can be well balanced.
 The quality of the balance is important. Imperical/stactic methods have limits.
 An unbalanced engine will always make less power than a well balanced one.
 The 45 degree angle with Harleys ignition timing approaches the power impulses of a large single. Take a sporty on a dirt road and goose it. It will leave a dotted line. Very helpful in dirt oval competitions, as it allows the tire to rebite.

I was reading a rather in-depth discussion of 90 degree Vee transverse vs 90 degree longitudal ( Ducati vs Moto Guzzi) configurations, and with all the discussion of primary, secondary and tertiary vibration modes, and the concept of rotational vibration with power and compression impulses alternately accelerating and decelerating crank rotation, I was ready to conclude that NO piston engine could be truly smooth.

Since all the Revolution series are 60 degree engines, it seems like HD is getting behind 60 degree Vees, but I kind of like Yamaha's 70 and 75 degree Vees.  It seems like selection of cylinder angle has more to do with design of intake (single or dual carb & placement) and exhaust plumbing, than it does with concern over primary balance.

My list of single crankpin Vee engines is growing.  It seems like most of the metric cruisers were built with single pin cranks.  I'm having difficulty finding examples of Vee twins equipped with balance shafts.  Perhaps the newest HDs and Indians?

[Guaire]

"Would the 60 degree Sportster mill actually produce less vibration to the point it's an undeniably better engine? You know, less rider fatigue, less mechanical fatigue, more hp potential, etc."

I've been riding my 2016 XG750 for over a year now. It is a 60 degree motor. There's no comparing the the two machines. Inherently, a 45 degree V can not be balanced. The XG is also counter balanced.
  This motor is liquid cooled, with 4 valve cylinder heads. This means  as you rev the motor the power keeps coming on. On a two valve head, the tendency is for a strong torque off idle, but the draw back is as the rpm's increase, the power drops off for lack of breathing.
  Keep in mind that HD didn't change the cylinder angle when they switched to the EVO engine around 1986. The non-thinking HD disciples would have broken out their usual mantra if there was a change in degrees. "That's not a Harley". That's their curse. But, HD added 50 pounds of weight to rubber mount the XL motor to deal with the obvious problem of the motor.
  The XG lead the way to the current very improved HD motors.
  At my height, the XG is the best Harley made. I understand that some riders in the 6 feet and a half range, need those long wheel base old Vs just to be comfortable. For me, I prefer my smooth 4 valved jugs 750.

[cyrusb]

Anything that rotates can have its balance factor improved.
 Firing order has a lot to do with harmonics as well.
 Harleys I have dealt with (pre evo) had interesting ignition. The front cylinder carried more load with its front facing exhaust port. And the bike was timed to it. Take a look at an older hogs distributor/timer and you will see completely different lobes for front and rear cylinders.

[Arschloch]

I still don't understand how the belt drive could have ever made it onto Harley and basically became a standard in that conpany considering the amount of conservative forces especially in the clientele. Maybe the be demand for virtually freedom from maintainance, on the other hand HD owners like to screw on their bikes or is that limited to the esthetics only those days?

[cyrusb]

I still don't understand how the belt drive could have ever made it onto Harley and basically became a standard in that conpany considering the amount of conservative forces especially in the clientele. Maybe the be demand for virtually freedom from maintainance, on the other hand HD owners like to screw on their bikes or is that limited to the esthetics only those days?

I hear that! I think it was the changing of the guard . Gone are the greasy vests and riders that serviced their own machines. Go to a rally now and smell the brand new leather.

[Guaire]

Otto and CyrusB - When it comes to chain set up and maintenance, versus the ease of belt drive... the belt won.
  Lots of geezers who want the 'classic' Harley can't cut it as mechanics. Several years ago I saw a HD rider standing with his bike. He said the mechanic changed the points. I offered to help, knowing that the thickness of a match book cover is 0.15". He declined and continued to wait for the tow truck.
Lots of Royal Enfield guys have done more roadside work than a lot of the HD guys have done in their garages.
  Guys on the HD Street Forum found a defective bolt on the primary gear on the front pulley. Lots of new street 500/750 guys were reluctant to do the fix. I made a movie how-to. But, mostly the Street guys just enjoy the bike , its performance and reliability. So I made the video to encourage riders... it can be done. It's easy!
https://www.youtube.com/watch?v=-HzjJxy15FI&t=68s

[tooseevee]

 Firing order has a lot to do with harmonics as well.
 Harleys I have dealt with (pre evo) had interesting ignition. The front cylinder carried more load with its front facing exhaust port. And the bike was timed to it. Take a look at an older hogs distributor/timer and you will see completely different lobes for front and rear cylinders.

     I don't know what you mean by the front cylinder "carries more load", but the lobes on the points camshaft are  different widths because when the front piston is at TDC, e.g., the rear piston is NOT at BDC. This lope in the combustion strokes is what makes the 45 degree knuckles, pans and shovels sound the way they do.

     When you static time a shovel at full advance (32BTDC) on the narrow lobe the wide lobe (rear cyl) is also set for that lope in timing. When you remove the points cam lock, the timing retards back it's correct idle timing position.

     And harleys are 45 degree V-Twins simply because that's what fit best into the bicycle frames used in those early days.

      But I'm sure you know all this I guess this is for them what don't.

[AzCal Retred]

@ #18: The hardscrabble DIY "Grease Bikers" faded out in the 70's, it's mostly Doctors, Lawyers & Plumbers now. "Serial" touched on this.

Martin Mull, Serial
https://en.wikipedia.org/wiki/Serial_(1980_film)

[Karl Childers]

What has changed is the need for specialized tools and very expensive ones at that. Just to get into the cam chest and swap out the cams on a twin cam or Milwaukee Eight requires and number of special tools. A one time job for a lot of DIYS'ers,  owners weigh out which is cheaper the tools and do the labor or have the dealer do the work, often the dealer wins out. Maintenance on the newer Harleys amounts to changing three different oils. No valve lash to set carbs, to adjust, etc. A lot of guys who own them tackle that. Belts? While I was skeptical at first they have proven very reliable  without the mess of cleaning and oiling a chain. Do a visual inspection now and then check the tension which seldom needs adjustment and your good to go. There's still a lot of Blue collar guys riding Harley's, used low mileage models proliferate on Craig's list and people of modest means can and do buy them. The brand new $35 K tour yachts are what the doctors and lawyers are buying.

[Karl Childers]

Otto and CyrusB - When it comes to chain set up and maintenance, versus the ease of belt drive... the belt won.
  Lots of geezers who want the 'classic' Harley can't cut it as mechanics. Several years ago I saw a HD rider standing with his bike. He said the mechanic changed the points. I offered to help, knowing that the thickness of a match book cover is 0.15". He declined and continued to wait for the tow truck.
Lots of Royal Enfield guys have done more roadside work than a lot of the HD guys have done in their garages.
  Guys on the HD Street Forum found a defective bolt on the primary gear on the front pulley. Lots of new street 500/750 guys were reluctant to do the fix. I made a movie how-to. But, mostly the Street guys just enjoy the bike , its performance and reliability. So I made the video to encourage riders... it can be done. It's easy!
https://www.youtube.com/watch?v=-HzjJxy15FI&t=68s

Harley moves into the future with bikes like yours and probably for the better if they are to survive. Still there is a place at least for now for the models that have strong link to the past, that huge wave of torque from a big inch motor, the sound and feel, some motorcycles move the body others move the soul. I had this out yesterday and had a hard time wiping the grin off my face when I got home!

[Arschloch]

Covid doctors buying the 35k$ junk iron collections for sure. 

Probably as capital investment, may they unconsciously realize their work is woth as much as hemorrhoids in your ars?

[AzCal Retred]

"they (Covid doctors, i.e. any E.R. doctor....) unconsciously realize their work is woth (worth?) as much as hemorrhoids in your ars?"
Not so very long ago Italy, France, England, Germany, Los Estados Unidos, Brazil, China, and even your beloved Russia all had scads of gasping, choking folks with splitting headaches show up in record numbers. The USA (We're #1!!) had refrigerated semi-trailers full of corpses outside many of their hospitals, a first in my lifetime.
There's a good chance that these sick gaspers were happy to have some assistance. More than a few were "Unmasked Vaccine Deniers" that (amazingly) had a change of heart when faced with their own mortality.
Rendering that care was real hard on those medical folks, a great many died of C19 along with their patients, something about continuous exposure aiding transmission. It takes a real "ars" to denigrate the medical folks that have done their best for about 3 years now to keep their non-masking, non-vaccinating patients alive. Next time you need the E.R., those "worthless as hemorrhoids" folks will be the care providers treating you. Of course the GOP over here has a plan - "crawl under a bush & die" seems to be the crux of it. Not real popular with anyone on the receiving end.

[GlennF]

Well you do need to remember that those that died were often from the poorer parts of town and tended to be non-white, old and already sick and would have died in a few years anyway, so they do not really count as Covid deaths.   Covid just hurried them along. 

Actually important people such as movie stars, politicians and business owners rarely died so even though the statistics look bad you have to remember that the deaths were among people that are a burden to society rather than anyone actually important. 

At least in America.  In Australia we think differently and almost 99% of the population decided to go and get vaccinated.  The anti-vaxers here are regarded by most of the rest of the population as un-Australian very selfish idiots.

[cyrusb]

     I don't know what you mean by the front cylinder "carries more load", but the lobes on the points camshaft are  different widths because when the front piston is at TDC, e.g., the rear piston is NOT at BDC. This lope in the combustion strokes is what makes the 45 degree knuckles, pans and shovels sound the way they do.

     When you static time a shovel at full advance (32BTDC) on the narrow lobe the wide lobe (rear cyl) is also set for that lope in timing. When you remove the points cam lock, the timing retards back it's correct idle timing position.

     And harleys are 45 degree V-Twins simply because that's what fit best into the bicycle frames used in those early days.

      But I'm sure you know all this I guess this is for them what don't.

Im speaking not only about the 315/405 degree firing order but the different lobe shapes in the timer. I believe those different shaped lobes bake in more advance for the front cylinder. Certainly the firing order would put the lobes in odd positions, but why would they have different shapes? And different dwell times?

[Arschloch]

"they (Covid doctors, i.e. any E.R. doctor....) unconsciously realize their work is woth (worth?) as much as hemorrhoids in your ars?"
Not so very long ago Italy, France, England, Germany, Los Estados Unidos, Brazil, China, and even your beloved Russia all had scads of gasping, choking folks with splitting headaches show up in record numbers. The USA (We're #1!!) had refrigerated semi-trailers full of corpses outside many of their hospitals, a first in my lifetime.
There's a good chance that these sick gaspers were happy to have some assistance. More than a few were "Unmasked Vaccine Deniers" that (amazingly) had a change of heart when faced with their own mortality.
Rendering that care was real hard on those medical folks, a great many died of C19 along with their patients, something about continuous exposure aiding transmission. It takes a real "ars" to denigrate the medical folks that have done their best for about 3 years now to keep their non-masking, non-vaccinating patients alive. Next time you need the E.R., those "worthless as hemorrhoids" folks will be the care providers treating you. Of course the GOP over here has a plan - "crawl under a bush & die" seems to be the crux of it. Not real popular with anyone on the receiving end.

The amount of folks getting ripped of to pay for the world saving "VaXX" who got a stroke and as an thank you an vaXX injection into their ars which caused their death is definitely greater. 31 silver ounzes for every "doctor" injecting that crap, now apparently mandatory for infants in some countries.

[AzCal Retred]

@ #27 +1! Well put -"the deaths were among people that are a burden to society rather than anyone actually important. " As C19 tended to be greater in the 60+ age group, I'm thinking that there was some "Estate Anticipation" driving part of that - "Hurry up & shuffle off and gimme your accumulated stuff". The largely unaffected 20 - 45 year old adult children are funny that way - watch the post-death "House Raid" technique displayed by many "grieving" offspring. One friend told us about her siblings initiating a raid after her fathers death. She said she had to go over and point out to the sibling that her mother was still alive, maybe put that stuff back..." 

@ #29: ...was it time for the "Two Minute Hate"?
"who got a stroke and as an thank you an vaXX injection into their ars which caused their death is definitely greater"
Any real-world data to back that up? Want to show us the mountain of corpses it would take to verify that absurdity? Want to explain why an all-powerful, world-wide conspiracy involving hundreds of millions of conspirators, that never broke cover wouldn't be able to simply eliminate the Internet-driven disinformation campaign? Putin & Xi Jinping thank you for your service.

[Arschloch]

Why would China thank me? The're the most ruthless covid home jail enforcers. Thank god most folks got sense and threw that mask away. If they fake vaxxines, we fake vaxxpasports, simple.

Unfortunately, some young folks that got that vaxx mainly due to their solidarity with the older folks that apparently have been sitting their whole life at home on benefits thus have unbreakable faith into government actions still clinch on to the masks.

And I still test every day to protect you. 

https://www.theweek.co.uk/92733/why-is-brazil-s-lula-still-so-popular

Brazil though may turn out of your favour when this guy wins and the commies take over. Too bad, however expectable turnaround when the pseudo capitalists can't confirm to the tiniest rule that common sense would command.

[AzCal Retred]

Why would China thank me? ..ummm...you are their proxy representative? You promulgate their message, furthering their goals? The Chinese are trying to get to zero covid, tough to do with Sinovax.
https://www.bloomberg.com/news/articles/2022-04-26/china-covid-situation-worsened-by-lack-of-local-mrna-vaccine

Unfortunately, some young folks that got that vaxx mainly due to their solidarity with the older folks that apparently have been sitting their whole life at home on benefits thus have unbreakable faith into government actions still clinch on to the masks.
This is just a collage of undocumented & unassociated random thoughts. Masks slow disease transmission via droplets, pretty well documented, not really a debatable point.

Brazil is just looking better & better for you. Can't wait to see that Pan-American Highway "Trip/Ride Report".

[Arschloch]

https://youtu.be/LijE698arz8

Well California is looking better by the day too. Maybe you can soon start as a supervisor builing the large Hydrogen plants. 

[AzCal Retred]

That'd finally be a step in the right direction. Surplus Residential & Commercial PV could be given the option of storage and then later sale through a generating facility at better rates of return instead of the 2 cent/KWH at present. One MW of generation to PG&E gets you $20, selling thru a 3rd-party generator could get you $50 - $100.
California is awash with oil wells and salt domes, so cheap H2 storage is available. It's just metering and a few electrolyzers and you are there.

New Tech!
https://www.bbc.com/news/uk-scotland-scotland-business-61758782
Green light for £21m Scottish plastic-to-hydrogen plant
Plans for a £20m facility in West Dunbartonshire that will turn plastic waste into hydrogen have been approved.
West Dunbartonshire Council has given the green light for the site at Rothesay Dock on the north bank of the River Clyde.
The plant, which will take an estimated 15 months to construct, will be the second of its kind in the UK.
The plans were lodged by Peel NRE, which is part of Peel L&P.
Peel said the facility would use new technology to create a local source of sustainable hydrogen from non-recyclable plastics otherwise destined for landfill, incineration or export overseas.
The hydrogen will be used as a clean fuel for HGVs, buses and cars, with plans for a linked hydrogen refuelling station on the site.

[GlennF]

https://youtu.be/LijE698arz8

Well California is looking better by the day too. Maybe you can soon start as a supervisor builing the large Hydrogen plants. 

lol ... California has no hope.  While the Americans argue pointlessly about conspiracy inspired evils of hydrogen Australia is just settling down and getting it done.

https://www.austrade.gov.au/news/success-stories/australia-a-global-first-with-dual-fuel-hydrogen-power-plant#:~:text=2%20February%202022,power%20generation%20during%20the%202020s.

https://www.industry.gov.au/policies-and-initiatives/growing-australias-hydrogen-industry/hydrogen-energy-supply-chain-pilot-project

https://research.csiro.au/hyresource/murchison-hydrogen-renewables-project/#:~:text=The%20project%2C%20located%20near%20Kalbarri,ammonia%2C%20mainly%20for%20export%20purposes.

https://bigrigs.com.au/index.php/2022/05/13/australias-most-ambitious-hydrogen-mobility-project/

[tooseevee]

Im speaking not only about the 315/405 degree firing order but the different lobe shapes in the timer. I believe those different shaped lobes bake in more advance for the front cylinder. Certainly the firing order would put the lobes in odd positions, but why would they have different shapes? And different dwell times?

    They have to be different because TDCs on the two cylinders are NOT 180 apart so the opening instants cannot be 180 apart. That's why the narrow lobe & the wide lobe.

    And remember both plugs fire when the narrow lobe opens & both plugs fire when the wide lobe opens.

    I think I remember you need around 35 degrees of dwell. There's more than that between the narrow & the wide lobe. I only had a 6 month CG Electronics Tech School in1959 & I hate electrickery, let alone theoretical electrickery, so I ain't gonna guess in what microscopic way dwell might be effected by the delta in lobe widths  

   

   

[NVDucati]

This engine gets mounted longitudinally in their shaft drive bikes and transversely for the chain drive models.
Mainly, I just love cutaway drawings.