Suzuki Hayabusa Inline Five

[Rage]

I think this is a very cool project

https://www.engineswapdepot.com/?p=20296

[humble sabot]

I'm trying to understand the justification for ever building a 5 cylinder at all. But It's an interesting choice.

[Facts Only]

People have literally run out of things to do with Hay abusa engines by the looks of it. Turbocharged, Supercharged, Big Bore, Long Stroke, billet block for hewland gearbox, V8 version all been done so now it's this. Seems a tad pointless but I bet it will sound mental.

[roon]

People have literally run out of things to do with Hay abusa engines by the looks of it. Turbocharged, Supercharged, Big Bore, Long Stroke, billet block for hewland gearbox, V8 version all been done so now it's this. Seems a tad pointless but I bet it will sound mental.

Single, twin, triple, I6, V16, flat-8, and coffee-table variants still have yet to see the light of day.

[RicME85]

I'm trying to understand the justification for ever building a 5 cylinder at all. But It's an interesting choice.

Isnt it hat they are just trying to squeeze an extra cylinder into an existing frame rather than plucking 5 cylinder out of the air as an idea for a project

[humble sabot]

Why one then? Why not two and end up with a straight six? They're inherently smoother.
People have been making V8s from motorcycle engines for a few years now.

[RicME85]

because that is all the space they have got in the existing frame

[Maritimer]

Nevermind this, passive aggressive negative voters can kiss my butt

[humble sabot]

I've never heard that.

[Benard Bonhomme]

Inline 5 have the best natural balance iirc, even better than 6s

It is not about the balance, but the irregularity of the engine. Generally, engines with an uneven number of cylinders have an irregularity way better than engines with an even number of cylinders:

https://www.gtisoft.com/wp-content/uplo ... ITE_GM.pdf

[sosic2121]

Inline 5 have the best natural balance iirc, even better than 6s

I don't think that's true. Inline 5 requires balancing shaft.

[Maritimer]

Inline 5 have the best natural balance iirc, even better than 6s

I don't think that's true. Inline 5 requires balancing shaft.

Good enough then, lower internal friction might be what im thinking of

[Greg Locock]

True boxers, I6 and v12 (which is basically two I6s) have the best natural secondary balance . A balancer shaft works at one harmonic only (typically twice crankshaft speed aka second order) , but the piston on crank assembly generates a whole series of forces, not just second order.

i5s and v10s aren't horrible, but they aren't anything like as smooth as an I6 unless they have a balancer shaft. I3s and 90 degree V6s and your usual I4 all create lots of powerful inertial forces.

Roughly speaking an I4 vibrates at 20 g rms at the redline at WOT, an I6 is at 5g rms. 10-1000 Hz.

The disadvantage of I6s and so on is that the crankshaft is so long that you run into torsional and bending problems with the crank.

Friction wise, the fewer cylinders the better for a given capacity , and a balancer shaft also adds friction.

[Tommy Cookers]

a Mr Duckworth said DFV valve motion produced bigger forces than those normally regarded as the causes of vibration

[63l8qrrfy6]

a Mr Duckworth said DFV valve motion produced bigger forces than those normally regarded as the causes of vibration

Mostly because his 'constant acceleration cams' were particularly bad.
DFV cams were pretty out of date even for that time - the acceleration profile consisting of 3 'constant acceleration' plateaus resulted in infinite jerk at each transition.

His compliant idler was a clever band aid but spring failures were never really cured.