•   
  •   
  •   

Motorcycles The Harley-Davidson Eight-Valve Mystery

17:16  20 june  2018
17:16  20 june  2018 Source:   cycleworld.com

Harley-Davidson CEO Reaffirms Availability of Electric Motorcycle in 2019

  Harley-Davidson CEO Reaffirms Availability of Electric Motorcycle in 2019 The dream of an electric Harley-Davidson is alive and well.Normally motorcycle companies like to keep their plans for future products under wraps. However, Harley-Davidson isn’t in a normal position right now. The iconic American brand finds itself with slumping sales, especially in its home market. H-D has fallen behind in marketing its traditionally old-school motorcycles to a younger crowd who can’t get excited about paying a premium price for a bike that looks just like the one their dads rode when they were kids. Part of Harley’s solution to this problem is bringing an electric motorcycle to production.

The Harley - Davidson Eight - Valve Mystery . What and, equally important, when did Harry Ricardo contribute to The Motor Company’s cylinder-head design?

May 31, 2018 at 03:00PM. Ask Kevin. What and, equally important, when did Harry Ricardo contribute to The Motor Company’s cylinder-head design? Kevin Cameron digs for the truth about Harry Ricardo’s involvement with Harley - Davidson ’s eight - valve racer.

a car engine: This photo shows a cylinder head from a production Harley-Davidson side-valve engine designed according to Harry Ricardo's 1919 turbulent-head patent. As the piston rises on compression, mixture trapped between its crown and the fat, crescent-shaped flat area of the head to the left is © Provided by Bonnier Corporation This photo shows a cylinder head from a production Harley-Davidson side-valve engine designed according to Harry Ricardo's 1919 turbulent-head patent. As the piston rises on compression, mixture trapped between its crown and the fat, crescent-shaped flat area of the head to the left is "squished" out from between, forming a fast-moving jet that vigorously stirs the mixture in the combustion space. The resulting turbulence shreds and rapidly distributes the flame originating at the spark plug, allowing this type of head to achieve complete combustion before the heat-driven conditions necessary for detonation (engine knock) can occur. With this type of rapid combustion, an Indian Powerplus-based side-valve racer, running on the Rockingham, New Hampshire, board track, was able on August 21, 1926, to set the all-time record of 120.3 mph for a single lap. The rider was M.K. "Curly" Fredericks. This record eclipsed the performances of the supposedly more "advanced" OHV eight-valve machines of Harley and Indian, and that of the overhead-cam Cyclone racer.

What and, equally important, when did Harry Ricardo contribute to The Motor Company’s cylinder-head design?

Harley-Davidson Recalls 250,000 Bikes for Faulty Brakes

  Harley-Davidson Recalls 250,000 Bikes for Faulty Brakes So far 2018 isn’t off to a great start for Harley-Davidson. So far 2018 isn’t off to a great start for Harley-Davidson. On top of a steadily declining customer base, the announcement of the Kansas City plant closure, and the president’s recent metal tariffs, the MoCo has just issued a massive recall of roughly 250,000 motorcycles worldwide on account of a brake problem that can supposedly result in sudden failure. The recall affects the ABS on 2008 to 2011 model year Touring, CVO Touring, and VRSC machines. Sadly, this isn’t Harley-Davidson's first ABS recall in recent years.

Did English internal-combustion-engine pioneer Harry Ricardo perfect the eight - valve cylinder head? US motorcycle historian Harry Sucher says he did on page 37 of his book, Harley - Davidson : The Milwaukee Marvel.

But Ricardo did not yet know any of this in 1915 when Ottaway was developing Harley’s eight - valve racer. House of Harley - Davidson to host 7th annual Law Enforcement Ride on Saturday, June 9.

Did English internal-combustion-engine pioneer Harry Ricardo perfect the eight-valve cylinder head? US motorcycle historian Harry Sucher says he did on page 37 of his book, Harley-Davidson: The Milwaukee Marvel.

“Under Ottaway’s direction, several prototype engines were built and tested, but [detonation] problems and spark-plug failures were encountered, even though the interior shapes of the cylinder heads closely followed profiles recently developed by Ricardo in his epoch-making experiments in cylinder-head design.”

When Bill Ottaway, Harley-Davidson’s first racing manager/engineer, suggested seeking Ricardo’s advice, he was told bringing him from England to the US would be too expensive. Ottaway, noting that $25,000 had already been spent on eight-valve development without finding a solution, was then able to persuade Walter Davidson to engage the English consultant.

Harley-Davidson Q1 Financial Report Has Good News and Bad News

  Harley-Davidson Q1 Financial Report Has Good News and Bad News Revenue is up, sales are down, and market share is just barely over 50 percent.Revenue is up 2.7 percent over last year despite motorcycle shipments going down a fairly significant 9.7 percent. How can you increase revenue with a decrease in shipments? Likely with service, higher transaction prices, and of course, selling lots of Harley-Davidson branded trinkets like t-shirts, boots, bandanas, paperweights, etc. Net income is down 6.2 percent and earnings per share is down 1.9 percent. U.S. retail market share is down a slight 0.9 percent to 50.4 percent for 601 cubic centimeters and bigger motorcycles.

The Harley - Davidson Eight - Valve Mystery http://cycleworld.co/YgJ6Tu via @cycleworldmag.

The Harley - Davidson Eight - Valve Mystery . Kevin Cameron digs for the truth about Harry Ricardo’s involvement with Harley - Davidson ’s eight - valve racer. You might be surprised to learn what he discovered.

“After several weeks of experimentation, Ricardo at last came up with acceptable results, the new engines turning out a creditable 55 hp from the standard 61-cubic-inch configuration. And this in 1915!” Using standard data for US inflation, $25,000 in ’15 translates to $610,000 today—serious money!

But there are problems. At that time, England was deep in World War I and Ricardo was a busy young man, 100 percent occupied with the design and development of an engine for the Mark V tank. That, plus the danger from German U-boats operating in the Atlantic, meant he could not possibly have crossed the Atlantic for a commercial consulting gig.

Combine this with the fact that “profiles recently developed by Ricardo in his epoch-making experiments in cylinder-head design” were not developed until 1918–’19 and made public under patent in 1919 after the war had ended. In this work, Ricardo discovered the relationship between charge turbulence and flame speed. By accelerating the flame speed with piston-to-head squish effect, he was able to burn the charge before it had time to become chemically altered by heat, causing it to detonate.

Harley-Davidson Shows off New Retro-Inspired Helmets

  Harley-Davidson Shows off New Retro-Inspired Helmets Old-school style, new-school protection.The three new helmets are in three distinct styles. There’s the Mason’s Yard Sun Shield three-quarter helmet that is a chin bar away from being a full-face helmet. It has a two-tone brown/cream color scheme. You also get a retractable sun visor and it’s compatible with Harley-Davidson headsets. This retro/modern helmet will set you back $300.

The Harley - Davidson Eight - Valve Mystery . What and, equally important, when did Harry Ricardo contribute to The Motor Company’s cylinder-head design?

The Harley - Davidson Milwaukee- Eight engine is the ninth generation of "big twin" engines developed by the company, but only Harley's third all-new Big Twin in 80 years, first introduced in 2017. These engines differ from the traditional Harley Big Twin engines in that there are four valves per cylinder

The Squish Head

Ricardo’s squish head had application only to side-valve engines, yet Ottaway’s eight-valve was an OHV design to which side-valve solutions could not apply. Indeed, it was only in 1916 when Ricardo, using a high-speed cylinder-pressure indicator, had discovered that pre-ignition and detonation are completely different phenomena. In pre-ignition, something hot in the combustion chamber (glowing carbon deposits, an overheated spark-plug electrode, or the very hot exhaust valve itself) ignites the charge before the spark can do so. Engines survive only a very few cycles of this kind, as the center of the piston crown quickly over-temperatures, sags, and is then punched through by combustion gas pressure. On the engine indicator, pressure rises as the piston compresses the charge then spikes suddenly, long before the normal spark timing is reached.

But, in detonation, Ricardo could see combustion pressure rise occurring normally, some 10 degrees after the spark, continuing to rise to a normal peak some 11 degrees ATDC. Then, without warning, a sudden pressure spike typically destroyed the indicator apparatus. Clearly, combustion had been normal to that point, with the flame front arriving near the cylinder wall. Continuing research showed that small volumes of mixture, greatly heated by compression and nearby combustion, auto-ignited at the very edges of the chamber, producing sharp pressure spikes and an audible knocking sound as a result of burning at the speed of sound. In detonation, the edges of the piston are damaged, never the center of the dome.

After Harley spat, Trump woos other motorcycle makers to US

  After Harley spat, Trump woos other motorcycle makers to US <p>President Donald Trump said Tuesday his administration is working to bring other motorcycle companies to the United States after Harley-Davidson's decision to shift some production for European customers overseas.</p>President Donald Trump said Tuesday his administration is working to bring other motorcycle companies to the United States after Harley-Davidson's decision to shift some production for European customers overseas.

Jalopnik. The Harley - Davidson Eight - Valve Mystery . Did English internal-combustion-engine pioneer Harry Ricardo perfect the eight

2017 Harley - Davidson Street Glide with the 107ci Milwaukee- Eight . The new shallow valve design combined with faster combustion from two spark plugs per cylinder keeps some heat from being absorbed by pistons and heads.

But Ricardo did not yet know any of this in 1915 when Ottaway was developing Harley’s eight-valve racer. He would not have the freedom to investigate it until the war ended in November 1918, as he was engaged on Air Ministry development work.

Elsewhere in his book (page 101), Sucher refers to at least two Harley-Davidson side-valve engines as having Ricardo cylinder heads, the Model A single of 1926–’27, and the V-twin VLD. This is perfectly possible, as both designs post-date Ricardo’s 1919 turbulent-head patent. Another point is that Ricardo became known worldwide mainly as a result of the publication of his book, The High-Speed Internal Combustion Engine, in 1922–’23.

How can we resolve this mystery? I suspect but cannot prove that Ricardo did have a hand in a later one of the three or four versions of the eight-valve race engine that were built between 1915 and 1927. But it appears impossible that he could have solved its problems during WWI.

Subsequent authors, seeing the information presented in Sucher’s book, have repeated it without further investigation. This kind of perpetuation of error is actually quite common in engineering history. If you read the literature of the B-29 bomber, you will find that author after author attributes its Wright R-3350 engines’ tendency to catch fire in flight to having magnesium crankcases. In fact, all versions of that engine were built on crankcases of forged steel.

Because one author got a point wrong, a cascade of error resulted. I intend no criticism of Sucher’s opus, recording for us his innumerable conversations with people whose recollections illuminate fascinating past events.

Are the dates of any Ricardo consultations at Harley-Davidson immured in the fabled archives of The Motor Company? Can anyone know for sure?

Follow MSN Autos on Facebook and Twitter

A Closer Look At Harley-Davidson’s New 975 And 1,250cc V-Twin .
Kevin Cameron runs the numbers on the modular engines&nbsp;Harley’s just-announced program “More Roads to Harley-Davidson” introduces “a new modular 500cc to 1,250cc middleweight platform,” including 975 and 1,250 V-twin engines to launch in 2020. These are liquid-cooled, appear to have DOHC, and almost certainly have four valves per cylinder. Their vee angle is close to 60 degrees. Other than this we have no information.

—   Share news in the SOC. Networks

Topical videos:

This is interesting!