MotoGP Engines | Scream LOUD or Bang BIG?

why do moto gp engines sound so differently [Music] what did you know the way that the engine sounds also tells us a lot about how the engine is delivering power to the rear tire and how much feel the rider has for how much grip they have screamer and big bang refers to different types of fire patterns that can be used for engines with several cylinders in order to understand what a fire pattern is let's first wrap our heads around how a single cylinder four-stroke engine works we have the cylinder piston crankshaft spark plug intake valve and exhaust valve four-stroke refers to that the piston completes four separate strokes while turning the crankshaft the first stroke is called intake the intake valve is open and the piston pulls an air fuel mixture into the cylinder the second stroke is called compression the piston compresses an air fuel mixture the third stroke is called combustion this is where the spark plug ignites the air fuel mixture which pushes the piston down and keeps on rotating the crankshaft the fourth stroke is called exhaust the exhaust valve is open and the piston pushes the spent air fuel mixture out this is very simple to understand for a single cylinder engine but for a multiple cylinder engine we have to design a crank that sets the timing of when each piston moves up in relation to the other pistons say we have an inline 4 engine with 180 degree crankshaft which is a very common engine configuration in japanese sport bikes for this configuration a traditional screamer firing pattern spaces the power and exhaust pulses evenly this fire pattern generates a lot of power does not put a lot of load on the gearbox and makes it fairly easy to design an air box and exhaust system you see if we would fire off several cylinders at once we would have to feed a ton of air through the air box into the cylinder and we would have to exhaust a ton of exhaust fumes on the exhaust cycle however the traditional fire pattern comes with a downside that yamaha engineer masao furusava identified in the early 2000s in conjunction with rossi moving to yamaha so the yamaha m1 had an in-line 4 with a traditional firing pattern while test riding the bike rossi identified that it had great brakes and quick turn-in but that the power delivery was off he couldn't feel how much grip he had and therefore he couldn't put power to the ground furusava analyzed this in detail and realized that because the crankshaft doesn't rotate at a constant rate it creates something called inertia torque the crankshaft slows down and speeds up just a tiny bit during each revolution for an everyday street bike inertia torque is not a big problem because they do not rev that high but for a high revving moto gp bike it is a major problem at high rpms inertia torque generates vibrations at the contact patch limiting available grip it also generates vibrations that overpower the vibrations that can be felt from the power pulses which makes it very hard for the rider to feel how much grip they have furusava's solution to this was a new cross plane crankshaft with an irregular firing pattern the exact math of how this works is quite complex but with this configuration the crankshaft speed fluctuations are nearly eliminated and the engine only experiences three percent of the inertia torque than an engine with a regular firing pattern experiences this is what gives the yamaha m1 and street bike r1 its unique sound another interesting effect of this irregular firing pattern is the way that it delivers power pulses to the rear tire and now we get into the screamer versus big bang the bait so as you already know a screamer fire pattern delivers small power pulses evenly to the tire a big bang fire pattern delivers power pulses simultaneously or closely spaced together with a long rest until the next set of power pulses the big bang theory holds that when the tire sees the power pulses it starts distorting winding it up and reducing the amount of available grip the long pass between pulses allows the tire to unwind itself and thus provide grip for the next set of power pulses furthermore the big bang theory states that the initial violent power thrust pushes the tire into the ground generating more grip then there's something called the long bang theory which is essentially a development of the big bang theory it holds that if power pulses are arranged closely together they arrive without vibrations and less peak load the tire then has some time to unwind itself between power pulse sessions furthermore the long bang theory states that there is an initial softening effect from trying to force air through the air box for four closely linked intake sequences to this day tire engineers have not been able to explain exactly how this works but in practice big bang engines do deliver power more smoothly and the riders can accelerate harder out of the corners as far as i could find in 2020 the manufacturers were running the following configurations so what's the deal with the v4 why is it such a popular engine configuration let's first look at a 90 degree v4 with a regular 360 degree crankshaft and a ducati twin pulse fire sequence this configuration does not see any speed fluctuations such as you would in an inline four since when the first piston accelerates down the second piston arrives at the top one piston is trying to accelerate the crank and one is trying to slow it down thus eliminating any inertia torque what seems to have driven the factories to run specifically 90 degree v4 with a 180 degree crank is that dorna unified the software in 2016 which meant that the manufacturers had to rely far more on mechanical means to get performance and tune the power delivery so why would you ever want to have a different engine configuration than a 90 degree v4 and why would you ever want an inline four now we have to talk about chassis design a 90 degree v4 has a lot of disadvantages for the chassis first of all they are long which means that the wheelbase has to be kept long which means that the bike will turn in slower the rear cylinder also creates a ton of heat which means a bunch of complex engineering is needed for the air box fuel tank and exhaust system they're also complex to position in a way where the mass is centralized an inline four is much easier to position for mass centralization and enables a short wheelbase this is why the suzukis and yamaha have superior corner speed with the downside that they do not have as high top speed as the v4 bikes i hope you learned something today i certainly learned a lot just researching for this video remember to subscribe to my channel there's always something new to learn [Music] it's got to be against the ladder looks just damn good cause baby i feel real good and i wish i was [Music] it's time to make it happen when we hit this street now

Channel: Mike on Bikes

Views: 451,757

Keywords: motogp, MotoGP Engines, motogp engine sound, motogp engines explained, motogp engine comparison, moto gp, grand prix, ducati, suzuki, aprilia, valentino rossi, ktm, rossi, racing, motorsport, motogp 2020, MotoGP Engine Configurations Comparison, Engine, MotoGP, Tech, Noise, V4, Inline 4, Big Bang, Screamer, Honda, Yamaha, Aprilia, KTM, top 10, motorcycle engine sound, motorcycles engine, extreme motorbike engine, crazy motorcycles engine, monster motorcycle engines, honda, best sounding bikes

Id: 05aHQT9_7IQ

Length: 8min 16sec (496 seconds)

Published: Fri Nov 27 2020