Why is the V-4 so underutilized in motorcycles?

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I owned both an '83 V-65 Magna, and an '89 Vmax. Both pulled hard at low RPM's, but the Max definitely pulled harder...

Not surprised.

The V max in our group was an anomaly, it had the "V-Boost" disabled as well as cam and head work done to it that stepped on the bottom half of its delivery.

Nigel Patricks work on it was less effective than his suzuki work.
 
BLS been broken recording this stuff since 2008, maybe longer. 😄

https://www.speedzilla.com/threads/behold-yamahas-virtual-v4.52453/
Yup... FWIW, he almost single-handedly destroyed the Speedzilla site with his never-ending diatribes (some of which are showing up here nauseum).

Now then, interesting write-up on his (in)famous RC45: https://www.bennetts.co.uk/bikesoci...ures/racing/aaron-slight-the-honda-rc45-years One can easily find many more credible write-ups highlighting the tremendous challenges Honda faced in trying to make this heir to the RC30 competitive. Definitely one of Honda's noteworthy underachievers (ranks right up there with its current V4-powered MotoGP bike which, deprived of the near magical talent of Marc Marquez, has made HRC the laughing stock of the paddock; lots of reading material available on that too, lol)

FWIW, Honda abandoned the RC45 after the 1999 season (after emptying the cupboard for it to win 1 WSBK title in 97, a full 4 years after its release, under the mercurial John Kocinski) in favour of the RC-51 (which won its first year out with Edwards at the helm). Curiously, the bike it narrowly beat in 2000 was the Yamaha R7 piloted by Haga. Sadly for Haga, he failed a drug test due to his use of a slimming agent, bringing his title hunt to an end (this after Honda abandoned it couldn't be competitive on a 750).

Many years on, the BLS saga continues... same old diagrams, same old (extremely selective and misguided) article quotes... same old, same old...

All engine types and configurations have their charm, advocates and detractors. Being able to choose from among all these different bikes is just one of the things that makes motorcycling such a blast.
 
Of course I've heard a V-Max with aftermarket exhaust. I stand by my statement that I don't like their sound. I don't like the sound of a parallel twin either. While I love a Porsche flat-6 I can't stand to hear a silly little Subaru flat-4 sputtering across the parking lot.

Here is just one of my collectibles. My pursuit of a museum quality H2 Mach IV Kawasaki is ongoing. Unfortunately I have no desire to add a V-Max, an Interceptor of any flavor or a Sabre/Magna to my collection. The CBX is iconic. The V-4's? Not so much.

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I had a red '79 CBX. Bought it brand new, it was still in the crate when I bought it...and to say the Vmax is not iconic is laughable...
 
Back in the Day I bought a brand new 1971 Mach III and sold it in 1976. I survived owning it when I was 18 years old !!! The Mach III Has a much more fun engine than the Mach 4 . I had some friends with the Mach 4s.
I had the 70 Mach III and a buddy of mine had a '73 750. I thought the 750 was more fun to ride simply because it was faster, but both would do wheelies like a dirt bike!
 
My understanding for going with a V4 configuration for racing is that they are narrower giving the motorcycle has less frontal area, thus less drag. Less drag means faster bike, quite a simple concept.
But then you run into problems like rear cylinder temps and exhaust routing. Just look at Ducati Panigale and how the rear exhaust snakes in the back to make it equal length to the front bank.

All this arguing which cylinder configuration makes more power or torque is quite silly and shows just how little people know about engineering compromises, especially the ones bringing up racing examples, when original discussion is for road applications.
 
Of course I've heard a V-Max with aftermarket exhaust. I stand by my statement that I don't like their sound. I don't like the sound of a parallel twin either. While I love a Porsche flat-6 I can't stand to hear a silly little Subaru flat-4 sputtering across the parking lot.

Here is just one of my collectibles. My pursuit of a museum quality H2 Mach IV Kawasaki is ongoing. Unfortunately I have no desire to add a V-Max, an Interceptor of any flavor or a Sabre/Magna to my collection. The CBX is iconic. The V-4's? Not so much.
Which "flavour" or variety of parallel twin? The 360-deg crank variety like the old Brit twins? The 180-degree variety (like most Japanese twins)? The 270-degree type (which sounds just like a 90-degree Vee) as now used by Triumph, Honda, Yamaha,...? The KTM twins and their 285-degree crank phasing (which sound just like their 75-degree V-twins)? The Husqvarna Nuda with its 315-degree crank phasing which mimics a Harley? Just curious as they all sound very distinct from one another
 
Which "flavour" or variety of parallel twin? The 360-deg crank variety like the old Brit twins? The 180-degree variety (like most Japanese twins)? The 270-degree type (which sounds just like a 90-degree Vee) as now used by Triumph, Honda, Yamaha,...? The KTM twins and their 285-degree crank phasing (which sound just like their 75-degree V-twins)? The Husqvarna Nuda with its 315-degree crank phasing which mimics a Harley? Just curious as they all sound very distinct from one another
They do, but their firing order is still the same. I think my lawn mower uses a single crank pin for both cylinders placed at a 90º bank angle. It sounds like an old Honda VT500 which is fine for my lawn mower.
 
My understanding for going with a V4 configuration for racing is that they are narrower giving the motorcycle has less frontal area, thus less drag. Less drag means faster bike, quite a simple concept.
But then you run into problems like rear cylinder temps and exhaust routing. Just look at Ducati Panigale and how the rear exhaust snakes in the back to make it equal length to the front bank.

All this arguing which cylinder configuration makes more power or torque is quite silly and shows just how little people know about engineering compromises, especially the ones bringing up racing examples, when original discussion is for road applications.
People can keep saying engine configuration means nothing in terms of power delivery, but that statement continues to be wrong. Every single V-4 designed for use in street bikes has had the same power deliver characteristics; all produced both excellent low end torque, and excellent high RPM HP for their given displacement. All of the other engine configurations lack on one end of the RPM spectrum or the other...
 
People can keep saying engine configuration means nothing in terms of power delivery, but that statement continues to be wrong. Every single V-4 designed for use in street bikes has had the same power deliver characteristics; all produced both excellent low end torque, and excellent high RPM HP for their given displacement. All of the other engine configurations lack on one end of the RPM spectrum or the other...
Objective tests and dyno sheets tell a different story.

Incidentally, you'll not find an engine application more demanding than a boat motor (notably for low-end torque requirement), and yet most, if not all, four-cylinder fours-stroke outboards use inline fours. Have all these engineers got it wrong, or do they objectively understand that other design parameters are the real determinants of how power is delivered? My money is on the latter. Carry on.
 
Objective tests and dyno sheets tell a different story.
Yep ... would have to see dyno T and HP numbers of the same exact number of cylinders and displacement engines with different designs.
 
Yep ... would have to see dyno T and HP numbers of the same exact number of cylinders and displacement engines with different designs.
Indeed, and once the work is done, you will find peaky engines of all configurations and torquey engines of all configurations. FWIW, the flattest torque curves I have ever seen (literally straight horizontal lines) have been on Triumph triples... Inline fours decades ago were peaky, but engine design has greatly evolved since then. Today, all engines are now much better in in terms of torque curve while still delivering incredible peak power numbers. Again, there is no V4 voodoo...
 
Indeed, and once the work is done, you will find peaky engines of all configurations and torquey engines of all configurations. FWIW, the flattest torque curves I have ever seen (literally straight horizontal lines) have been on Triumph triples... Inline fours decades ago were peaky, but engine design has greatly evolved since then. Today, all engines are now much better in in terms of torque curve while still delivering incredible peak power numbers. Again, there is no V4 voodoo...
Speaking of triples ... the XSR900 has a very flat torque curve, and therefore a very linear HP curve. The bike is so much fun to ride, having 105-108 HP stock at the rear wheel and it only weighs 425 lbs with a full tank of gas.

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Objective tests and dyno sheets tell a different story.

Incidentally, you'll not find an engine application more demanding than a boat motor (notably for low-end torque requirement), and yet most, if not all, four-cylinder fours-stroke outboards use inline fours. Have all these engineers got it wrong, or do they objectively understand that other design parameters are the real determinants of how power is delivered? My money is on the latter. Carry on.
Beg to differ all you want. I stand by my statement. No other engine type for motorcycles intended for use on the street can match the low end torque, and high RPM HP for a given displacement. I'm inviting you to post one, but I know you aren't going to because none exist...
 
I just thought of an interesting story I thought I'd pass along. Back when I was in the Air Force, I served with a guy who worked in our shop. At the time I had an '89 Vmax. This other guy had a Kawasaki 1500 Vulcan. We were talking bikes one day and he brought up how hard the Vulcan pulled on the bottom end. I also mentioned how hard the Max pulled down low, so we decided to find out which bike pulled harder. Keep in mind, the Max gives 300ccs to the Vulcan, and I outweighed the other guy by at least 50 lbs. Starting from 30 MPH in top gear, the Max easily pulled away, and by the time we hit 50-55, the Max pulled away pretty hard. We never went past 70, by then the Max was pulling away so fast there was no sense in going any faster...
 
Definitely one of Honda's noteworthy underachievers
Negative... Honda's RC45 were engineered by HRC to achieve titles and achieve it most certainly did earning 35 total...

1st Suzuka 8 Hours Doug Polen Aaron Slight
1st Isle of Man TT F1 Steve Hislop
1st Isle of Man Senior Steve Hislop
1st NorthWest 200 Robert Dunlop
1st Ulster Gp Phillip McCallen
1st Australian Superbike Anthony Gobert

95 1st World Endurance Stéphane Mertens Jean-Michel Mattioli
1st 24 Hours of Le Mans Alex Vieira Rachel Nicotte Brian Morrison
1st Isle of Man TT F1 Phillip McCallen
1st Isle of Man TT Senior Joey Dunlop
1st AMA Superbike Miguel Duhamel
1st Ulster Gp Joey Dunlop
1st NorthWest Superbike Ian Simpson
1st Suzuka 8 Hours Aaron Slight Tadayuki Okada
1st Australian Superbike Kirk McCarthy

96
1st Isle of Man TT F1 Phillip McCallen
1st Isle of Man Senior Phillip McCallen
1st Dayton 200 Miguel Duhamel
1st NorthWest 200 Phillip McCallen
1st Ulster Gp Phillip McCallen

97
1st World Superbike John Kosinski
1st Isle of Man TT F1 Phillip McCallen
1st Isle of Man Senior Phillip McCallen
1st Suzuka 8 hours Shinichi Itoh Tohru Ukawa
1st NorthWest 200 Micheal Rutter

98
1st World Endurance Doug Pole Christian Lavieille
1st Isle of Man TT F1 Ian Simpson
1st Isle of Man Senior Ian Simpson
1st AMA Superbike Ben Bostrom
1st Macau GP Micheal Rutter
1st Suzuka 8 hours Shinichi Itoh Tohru Ukawa
1st NorthWest 200 Micheal Rutter

99
1st Dayton 200 Miguel Duhamel
1st Suzuka 8 hours Tadayuki Okada Alex Barros
1st Ulster Gp Joey Dunlop
 
I just thought of an interesting story I thought I'd pass along.
Funny I just thought of my Vmax story...

While stationed at McConnell AFB Kansas in 1985 the local Yamaha
dealer took delivery of his first Vmax... he organized a week end ride
from Wichita to Eureka Springs Arkansas to gain first person seat of the
pants knowledge in order to sell Yamaha's powerful V4 to prospective
customers... We were just giggling in our skid lids every time the
Yamaha billowed white smoke... he would burst the rear tire loose with
the throttle and power slide around the unsuspecting cagers... White
smoke became our Que to drop a gear and disappear around the next
bend...

Our group in 1985 1)Me and my 500 Interceptor 2)Kelly 750 Turbo 3)Steve
Yamaha 4)Frank 750 Interceptor

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