• Bikes for Sale
  • News
  • Buyer’s guide
    • Buy a Motorcycle
    • First Rides & Reviews
    • Specs, Prices & Others
  • Lifestyle
    • Concepts & Custom
    • Electric Motorcycles
    • Events
    • Motorsport
    • Tips & Stories
    • Travel
  • Locals
imotorbike logo
  • Bikes for Sale
  • News
  • Buyer’s guide
    • Buy a Motorcycle
    • First Rides & Reviews
    • Specs, Prices & Others
  • Lifestyle
    • Concepts & Custom
    • Electric Motorcycles
    • Events
    • Motorsport
    • Tips & Stories
    • Travel
  • Locals
  • Facebook

  • Instagram

  • X (Twitter)

  • YouTube

  • LinkedIn

  • RSS

The World’s First Oval Pistons Developed By Honda
Sathurshan
January 9, 2020

In 1979 Honda produced the world’s first engine which featured oval pistons with the introduction of the NR500 Grand Prix racer. The oval pistons later found their way in the 1980 NR750 endurance racer and the road going NR.

Honda NR500 Oval Pistons

Honda NR500 Oval Pistons in the Engine Assembly | Photo Credit: HRC

The Honda NR500

Honda’s 70s journey is what led to the creation of the oval pistons. In the 60s Honda had a successful Grand Prix journey before their absence in the early 70s. They decided to return to Grand Prix motorcycle racing in the late 70s. Honda realised during their absence Grand pix have taken over by two-strokes bikes compared to their four-stroke equivalent.

To compete in the Grand Prix  Honda preferred working on four-stroke engines. During the development stage, they looked into increasing the number of cylinders. Unfortunately, the Grand Prix rule allowed only a maximum of four cylinders. Honda engineers got back to the drawing board and tried to develop a V8 engine in the form of a four-cylinder engine.

Honda NR500 oval pistons

Honda NR500 Engine

The result of this was the NR500 under the NR (New Racing) series, featuring oval pistons with 32 valves and eight con-rods. That meant two con-rods per piston and eight valves per cylinder! On top of that, Honda engineers made all of these fit into a regular four-cylinder engine!

Honda NR500 oval pistons

Honda NR500 Assembly

Honda NR500 oval pistons

Honda NR500 | Photo Credit: Cycle World

The bike produced 130 bhp at 20,000 rpm, but it did not succeed on the track. The NR500 is one of the radical motorcycles in history that failed.  Honda later went ahead with using the NS500 two-stroke machine.

The Honda NR750

Honda GP, NR500 and NR750

Photo Credit: 95 Custom

Honda used the same technology in the NR750 endurance racer later in the 1980s. A few years later in 1992 Honda decided to produce 300 units of the road-going version of the NR750 as the Honda NR. The 750cc road-going NR’s featured elliptical-shaped pistons with long curved sides. The NR500, however, had oval pistons with straight sides.

NR500 Oval Piston

NR500 Oval Pistons | Photo Credit: Honda Global

NR750 Honda Oval Piston

NR750 Oval Pistons | Photo Credit: Honda Global

honda nr500 engine

Oval Piston Components

The 750cc 90-degree V-four engine with oval pistons allowed eight valves per cylinder just as the older NR500 engine. The engine generated a vast amount of power as the air/fuel ratio, and the compression in the cylinder increased dramatically compared to an ordinary V-four engine.

NR750 oval pistons

NR750 Engine Assembly | Photo Credit: On Road Zone

oval piston

Honda’s 750cc NR engine | Photo Credit: Honda

The stock road-going 750cc NR was capable of producing 125 bhp at 14,000rpm. When released, the NR cost $50,000. It is considered normal for a rare collectable motorcycle which has one of the most unique engineered and design quirks until today.

nr750 engine

Honda NR750 Engine using Oval Pistons | Photo Credit: Visor Down

Related Items70sfeaturedHondaNRNR500NR750Oval PistonPiston
To read the full story
login with google
login with facebook
or
Create an account for free
This won't cost you.
by clicking this button you agree to iMotorbike's visitor agreement
Already have an account? Sign in here
Click here to get notified on every new article
News
January 9, 2020
Sathurshan

A Mechanical Engineer with an addiction to the smell of petrol and loves anything automotive.

Related Items70sfeaturedHondaNRNR500NR750Oval PistonPiston

More in News

Ducati and Garage 51 present the V2 Future Champ Ducati Academy

Amzar HazeeqOctober 6, 2025
Read More

Aldeguer wins maiden MotoGP in Mandalika; Marquez and Bezzecchi collide.

Hazique ZairillOctober 6, 2025
Read More

Rueda Clinches 2025 Moto3 World Championship with Victory in Indonesia

Hazique ZairillOctober 6, 2025
Read More

Tighten Your Motorcycle Chain Like a Pro: The Simple DIY Guide Every Rider Needs

Amzar HazeeqOctober 6, 2025
Read More

The Journey Awaits: 6 Best Adventure Motorcycles You Can Buy in Malaysia Right Now

Amzar HazeeqOctober 6, 2025
Read More

Chigee AIO-6 LTE 4G Review: A Smart, Connected Display for Riders

Hazique ZairillOctober 6, 2025
Read More

Triumph Launches TXP Electric Trials Bike Range for Young Riders

Hazique ZairillOctober 3, 2025
Read More
Sepang

MotoGP 2026 Launch Event Relocated from Singapore to Kuala Lumpur

Hazique ZairillOctober 3, 2025
Read More

Motorcycle Quickshifter Explained – Benefits, Types, and How It Works

Amzar HazeeqOctober 3, 2025
Read More

Aprilia Racing Renews Technical Partnership with SC-Project for 2026 MotoGP Season

Hazique ZairillOctober 3, 2025
Read More

Honda HRC Confirms Somkiat Chantra and Jake Dixon for 2026 WorldSBK Season

Hazique ZairillOctober 3, 2025
Read More

Kawasaki Teases All-New KLE Adventure Bike

Michelle LiewOctober 2, 2025
Read More
We want to buy your bike Join us on Telegram
Scroll for more
Tap

Join us on Facebook

  • Popular

  • Latest

  • Comments

  • MotoGP to Kick Off 2026 Season with Global Launch in Singapore
    EventsSeptember 10, 2025
  • Moda Launches Affordable Moca Scooter in Malaysia
    Buyer's guideSeptember 10, 2025
  • Aprilia Unveils Ultra-Exclusive RSV4 X-GP at Catalunya GP 
    Buyer's guideSeptember 8, 2025
  • Royal Enfield Guerrilla 450 Review: The Most Un-Royal Enfield Ever
    Buyer's guideSeptember 9, 2025
  • Yamaha Unveils V4-Powered YZR-M1, Set for San Marino GP Wild-Card Debut
    MotoGPSeptember 12, 2025
  • iMotorbike Merdeka Ride 2025: A Journey of Unity, History, and Patriotism
    EventsSeptember 8, 2025
  • Italjet Dragster 300 Officially Launched in Malaysia, Priced from RM37,800 
    Buyer's guideSeptember 9, 2025
  • Ducati and Garage 51 present the V2 Future Champ Ducati Academy
    IndustryOctober 6, 2025
  • Aldeguer wins maiden MotoGP in Mandalika; Marquez and Bezzecchi collide.
    IndustryOctober 6, 2025
  • Rueda Clinches 2025 Moto3 World Championship with Victory in Indonesia
    LifestyleOctober 6, 2025
  • Tighten Your Motorcycle Chain Like a Pro: The Simple DIY Guide Every Rider Needs
    Buyer's guideOctober 6, 2025
  • The Journey Awaits: 6 Best Adventure Motorcycles You Can Buy in Malaysia Right Now
    Buyer's guideOctober 6, 2025
  • Chigee AIO-6 LTE 4G Review: A Smart, Connected Display for Riders
    Buyer's guideOctober 6, 2025
  • Triumph Launches TXP Electric Trials Bike Range for Young Riders
    Buyer's guideOctober 3, 2025
  • MV Agusta Lucky Explorer Project 9.5: testing the Schiranna prototype - news.iNthacity: More Top Breaking News and Popular Stories To Stay Informed says:

    […] Michelle Liew […]

  • CFMOTO 450SR to enter Malaysia in March 2023 at RM29,300 - news.iNthacity: More Top Breaking News and Popular Stories To Stay Informed says:

    […] Michelle Liew […]

  • Suzuki V-Strom now available in Malaysia at RM81,900 - news.iNthacity: More Top Breaking News and Popular Stories To Stay Informed says:

    […] Michelle Liew […]

  • Colin says:

    I hope they make the Dax street legal. Love to…

  • Mohd Razi bin Rosli says:

    Adv 150cc

  • Nena Maxberry says:

    Just curious what they would retail for

  • Adam Kenny says:

    RM4159 for the front fork is it?

Categories

  • Buyer's guide
    • First Rides & Reviews
    • Specs, Prices & Others
  • cafe racer malaysia murah
  • Campaign
  • CSR Programme
  • Electric Motorcycles
  • Electric Motorcycles
  • Industry
  • Industry
  • Kedai Motor
  • Lifestyle
    • Concepts & Custom
    • Electric Motorcycles
    • Events
      • EICMa
    • Helmet
    • Motorsport
      • ARRC
      • CubPrix
      • EWC
      • Moto3
      • Motocross
      • MSBK
      • WSBK
    • Tips & Stories
    • Travel
  • Moto2
  • Motor Murah
  • News
    • Locals
    • MotoGP
    • Scoop
  • Review
  • Scoop
  • Scoop
  • SEO
  • Suzuka 8 Hours
  • Tips & Tricks

Corporate

About Us
Terms of Use
Privacy Policy
Disclosure Policy
Contact Us
SUBSCRIBE NOW!

2024 iMotorbike World Sdn. Bhd.(1205246-M). All rights reserved.

Chinese manufacturer Niu introduces new electric bikes at CES
Monster Energy Yamaha’s Franco Caimi finishes 12th place in Stage 5
Nak Jual Beli Motor 😊 ?
WhatsApp
Hi iMotorbike 😊
Open chat