Yamaha YZF R1 Crossplane Crankshaft Technology Explained

Yamaha YZF R1 Crossplane Crankshaft Technology Explained


The crossplane or cross-plane is a crankshaft design for V8 engines with a 90° angle between the cylinder banks. The crossplane crankshaft is the configuration used in most V8 road cars.3d model of a cross-plane crankshaft demonstrating the 90 degree angle between the crank throws and the large counter weights.The crossplane crankshaft has four crankpins, each offset at 90° from the adjacent crankpins. The first and last of the four crank pins are at 180° with respect to each other as are the second and third, with each pair at 90° to the other, so that viewed from the end the crankshaft forms a cross. The crankpins are therefore in two planes crossed at 90°, hence the name crossplane. A crossplane crank may have up to five main bearings, and usually does, as well as large balancing weights. Crossplane V8 engines have uneven firing patterns within each cylinder bank, producing a distinctive burble in the exhaust note, but an even firing pattern overall. Their second-order balance, owing to the 90° bank angle and 90° throws, means no additional balance shaft is necessary to achieve greater smoothness. Without the 90° bank angle, a balance shaft may be required.
The other prominent design for a V8 crankshaft is the flatplane crankshaft, with all crankpins in the same plane and the only offset 180°. Early V8 engines, modern racing engines and some others used or use the flatplane crankshaft, which is similar to that used in a straight four or flat-four engine. Flatplane V8 engines may use any angle between the cylinder banks, with 60° and 90° the most common. They lack the V8 burble and the superior mechanical balance of the crossplane design, but do not require the large crankshaft balancing weights. Inherent balance of the big ends is like a straight four, and modern designs often incorporate a balance shaft for smoothness. But without balance shafts, flatplane designs have the least flywheel effect of any V8s, which allows them to be more free-revving.
The crossplane design was first proposed in 1915, and developed by Cadillac and Peerless, both of whom produced flatplane V8s before introducing the crossplane design. Cadillac introduced the first crossplane in 1923, with Peerless following in 1924.
Inline-4 engines can also use the crossplane concept. The 2009 Yamaha YZF-R1 motorcycle uses the crossplane crankshaft and, in the absence of the 90° bank angle of the V8, must use a separate balance shaft geared off the crankshaft to eliminate the inherent vibration (a primary rocking couple) found in this type of crank.
A crossplane crank has been used in Yamaha’s M1 MotoGP racing models in the past. Yamaha claims advances in metal forging technologies make this a practical consumer product.


37 thoughts on “Yamaha YZF R1 Crossplane Crankshaft Technology Explained”

  1. Where is the advantage of this? At first glance it sounds like a stupid idea in a 4-inline engine design, V8 is a different story… Please don’t post marketing-BS like “they are more torquey”, and so on. I know the stories, but never had a good explanation for it!

  2. I might believe this if the engine is rotating at 10 RPM, but at the speeds bike engines run at I think this is a load of rubbish. If this had any technical merits all bike maker’s would have been using this since the year dot .

  3. Well then… I mean I guess at higher RPMs this isn’t a huge issue since there’s so much momentum in the crankshaft, but still, you have an extremely unbalanced firing order. To me it would seem like your engine output would then be “pulsing” because of the delay in the firing.

    If it works then it works, I just think it’s bizarre.

  4. I don’t get. With a conventional crank, you are going to get an impulse stroke exactly every 180 degrees(with a 4 stroke). You have 2 pistons counteracting the other 2. What could be smoother? They talk as if the crankshaft changes speed with each impulse stroke, It doesn’t. If the flywheel effect is what you want to get away from to increase acceleration, why go to a heavier crank assembly?

  5. The 4 in line with flatplane crankshaft (boneshaker) has better volumetric efficency (using 4 in 1 exhaust pipe). That is the reason it was used in F1.

  6. i left this on in the family room for my wife’s son to learn how to count and he now does my taxes

  7. MAYBE they should also try to make an all TNT-plane crankshaft… all 4 cylinders in the same TDC firing together, ..that will be a BLAST like 4 pistons firing together like a super large single, wonder how that will feel like.. a large engine enduro thumping thud thud thud?

  8. so you trade inertial imbalance for combustion imbalance.   why not just go to 3 (or5) cylinders and remove both imbalances?

  9. Haha….. gotta love that Gran Turismo music tho. good times, good times…. (growing up late 90’s wit a PS1, awesome console!)

  10. The graph they show at 3:38 for flat plane crank would be the smoothest torque delivery out of all of the other graphed options, it complements the torque peaks where the crossplane one looks like it would be constructive interference, amplifying the torque peaks and valleys

  11. This was considered ground-breaking? Seems rather obvious that you’d want all piston crank positions to be perpendicular to the previous firing piston, to assure you are always producing a power stroke (and torque) at any given portion of the crankshaft’s rotation.

  12. Yes yes yes, but classic inline 4 with just une balancer revs faster, S1000, zx10, gsxr1000.

  13. The two best in line 4 Superbikes of 2017 use regular camshaft, BMW S1000RR and Suzuki GSX-R 1000R, both have MORE POWER and MORE TORQUE, not to mention ZX10, and MV Augusta F4 RR….

  14. the music thing or drums is beyond stupid, just play a sound when the piston fires. When he says “1-2-3-1-2-1-1-2” , the 1’s are the spark plug, and the 2’s and 3’s are 90 degree phases between the firing, so if he goes to 3, it was 270 degrees, 2 was 180 degrees, and 1 was only 90 degrees, so HIT-270-HIT-180-HIT-90-HIT-180 and start over. The drums are just confusing, with trumpets and drum sounds. I drew a diagram above

  15. The jibber jabber bullshit makes it harder to understand, not easier. The big problem for me personally is when they say that inertial torque is eliminated, but in reality, it is cut by 50%.

    Crossplane crank

    pin clock firing
    position order

    12 1

    9 3

    3 2

    6 4

    fire1 – 270 – fire3 – 180 – fire2 – 90 – fire4 – 180
    Crossplane crank

    **********************************************************
    flatplane crank

    pin clock firing
    position order

    12 1

    6 2

    6 4

    12 3

    fire1 – 180 – fire2 – 180 – fire4 – 180 – fire3 – 180
    flatplane crank

    ***********************************************************
    basically, when an engine is perfectly balanced like the flat plane, the engine accelerlates faster, but when it is uneven, such as a 270 degree pause and then a 90 degree pause, it allows the wheel to have more traction and the acceleration is more linear. However, If you are hooked up like in drag racing, and not coming out of a corner, you want the flat plane, if you are mostly on a track with turning, you want the crossplane. SO, the flatplane is better for long straights and few corners, like a triangle shaped track, or for a straight line like in drag racing.

  16. 😁😂 In real life is not working like in this movies!
    Another shit engine!!!! Heavy bike powerless freak engine and unuseful engine with a lot fuel consumtion and less power then previous Engine.

  17. When the big bang r1 came out it was way down on power, claimed 181 crank hp from Yamaha, dyno’d at 145wrhp.

  18. For motorcycles on a track the benefit of cross plane configuration is the uneven firing frequency, because then when the rear wheel breaks loose it can recover by itself. This means that the rider feels the rear wheel intermittently sliding and can back off on the throttle. With even firing intervalls the wheel just keeps sliding.

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