'Perfect fifth' hypothetical inline 5 cylinder engine audiovisual demonstration - gear shifting

A demonstration of the firing interval of an I5 with the crankshaft phased to create a perfect fifth between cylinders 1,5 (firing at 360º intervals) and 2,3,4 (firing at 240º intervals)

The firing order of this theoretical engine is 1 4 5 2 3, but it was supposed to be 1 3 5 2 4 (which would sound exactly the same) for symmetry, not sure how I missed that but i'm not making the video again.

Firing intervals are 0º, 180º, 360º, 420º, 660º for either firing order.

This crank configuration should have a smaller rocking moment than an even fire inline 5 cylinder engine, but second order shaking would probably be bigger/worse. I could model it crudely but that is getting way too far into the weeds.

An engine using this crankshaft would need primaries 1,5 merging into a tailpipe and primaries 2,3,4 merging into another tailpipe for maximum effect. This could make turbo sizing tricky.

I had the idea for this configuration a long time ago but was putting too much thought in to the relative positions of the outer two and inner three crank throws, after making the three engines synchronised program/video I realised it didn't have much impact on the sound.

[VwBora]

When you go "downshift" let the rpm pass 500-800rpm above the previous gear, it will sound less artificial

[spamcan]

I like that you have info on the exhaust pairings too. I always thought it was clever how engineers took advantage of the pulses of fast moving exhaust gases to make more power, either by scavenging or optimally hitting a turbine wheel. Crazy stuff, wish I was smarter to fully understand and appreciate it.

[FocusST]

Just watched the i6 video This is leaps and bounds above

[jacquescrusan]

Perfect 5th; You're proving me right, William.
Makes this engine sound more like an inline 6. Just like how the new triumph tiger (inline 3 with 90 degree crank throw spacing instead of the typical 120 degrees) sounds like an R1.

[Xaserix]

with the gear shifting it just sounds even better

[thedefaultguy]

This legit sounds like a Porsche Gt3-rs

[Deviation]

Binging on these videos now. This is a great audio feast. These engines actually built would work well in motorbikes where the drive train could cop the unique harmonic vibrations without too much wear. FWD cars may also be able to use these engines with reasonably reliable transmissions. I am a super huge fan of the cross-plane four engine being adopted into use with "Hatchback" sized cars, but such engines apparently develop less overal horsepower than the flat-plane bread and butter equivalents. In general auto engineers won't touch the idea, though it worked very well in GP bikes for a little while.

[jonfeuerborn]

Curious Onlooker-What kind of engine is that?

Mr. Moser-It's a specially tuned Beethoven I5.

[bendriscoll]

That sounds absolutely beautiful, like a small V10.

Please do a Ducati V4 next.

[isaacsrandomvideos]

I found out if you tap hard on a microphone around 5 times, speed it up then loop it it sounds identical to a 5 cylinder

[Dewey]

When you can make an inline 5 sound like a Testarossa

[wdowa]

Sounds weird... Like misfiring V10 But this method of audiovisualising is so much better :)

[voldanmalak]

Love how you got this to sound like a 6-cyl, and your other video where you got had a 6-cyl sound like a v8. Pretty nuts what firing order does to the sound of an engine. I wonder what you could get an F1 V6 Hybrid to sound like with different firing orders.

[abysswalker]

would it be possible to make a slightly different low-load sound and then use that during the shift? it would drastically improve sound and realism of the upshifts I think :D

[EtiThaPro]

it sounds like an i6/v12 rather than an i5

[DeadCrow-kv]

I need the firing interval of these engine please.

[WebNstyne]

Is this a triple and twin firing order combined?

[KristianLyubenovYT]

it almost sounds like a raspy 911 gt3 996 imo

[elektroarkivet]

Lovely! <3 I want that engine in my vintage Saab! The best practical configuration would probably be a VR-5 or even a flat-5 but I can't really imagine what config would work best to reduce vibrations. Balance shafts can do miracle, but since I'm a great fan of minimalism and simplicity I think the winner is to arrange the cylinders in such a way that a balance shaft is not needed. If i remember right, the best even firing V8 is 90 degrees, and the most balanced V6 needs to have 120 degrees between the banks, resulting in an engine that isn't compact in any direction.

[rosemaryfriedwa]

Play on 2x speed and it'll sound slightly like the new V6 F1 engine