Suzuki Hayabusa Inline Five

[Tommy Cookers]

aren't the pulses of energy associated with a given valve motion are independent of the effects you describe ?
especially if the smoothing idler is working

yes I was hoping someone else would do some calculations

[63l8qrrfy6]

The compliant idler did decouple the crank train from the valvetrain, yes, but the valvetrain torsionals were still very bad.

While the cam operates the valve any forces due to spring vibration are turned into camshaft torque and radial loads.

[Rage]

https://www.engineswapdepot.com/?p=18927&


Very interesting crankshaft configuration, never seen a crankshaft like this before.

[Tommy Cookers]

it's not clear to me exactly how he has used the existing parts
if it was a 2 stroke of course it would be easy

the 4 stroke 125cc 5 cylinder Honda GP machine over 50 years ago was based on their 50cc twin
iirc it used the twin's crankshaft (180deg) coupled to a new 3 cylinder '120 deg' (strictly 240 deg) crankshaft
no great problem with 5 carbs and 5 exhaust systems
they were busy making new machines trying to win 4 World Championship classes so they took the easy ways around

[Rage]

First start up

https://www.youtube.com/watch?v=g-jc5ZBFgC0

[coaster]

That motor is a 4 + 1 and not a true 5.
It needs an evenly spaced crank and cams to be a 5.

[tok-tokkie]

That motor is a 4 + 1 and not a true 5.
It needs an evenly spaced crank and cams to be a 5.

We can see that from how he coupled 2 cranks together to make the 5. But what is the timing of #5? Same as #1 so they fire as a big bang? Or is it half way between #1 & #2 (firing order, not line position).
This post shows them numbered 4 3 2 1 5 https://www.engineswapdepot.com/?p=22846&

[coaster]

It looks like its a flat plane 4 with a 90 degree pin for number 5. The imbalance is profound, you can see the test stand move a foot in 30 seconds or so.

[humble sabot]

That's one of the most needlessly pedantic claims I've ever read on F1Technical. If it has five pistons in five chambers it is a five cylinder motor.

There are some seriously bizarre claims made around here, and i understand the innate need for pedantry around engineering but this takes the cake.

[coaster]

Oh really humble? What falls into the definition of proper design and a simple cut and paste? Please define? What passes as sound design in your mind?

[humble sabot]

I'm talking about your bizarre need to differentiate between an inline five and this engine, which is in every way five inline cylinders.

[coaster]

God i hate my last post, if the builder of this motor is reading please consider these steps;
Hayabusa 88mm bore spacing.
VW Jetta I5 88mm bore spacing.
48mm Vw big end journal?
Offset grind to 38mm big end,
10mm destroked.
Water jet cut a spacer for underneath the cylinder block to crankcase, machine to suit the stack height.

Its a start towards an even fire motor without resorting to a billet crank.

[Zynerji]

God i hate my last post, if the builder of this motor is reading please consider these steps;
Hayabusa 88mm bore spacing.
VW Jetta I5 88mm bore spacing.
48mm Vw big end journal?
Offset grind to 38mm big end,
10mm destroked.
Water jet cut a spacer for underneath the cylinder block to crankcase, machine to suit the stack height.

Its a start towards an even fire motor without resorting to a billet crank.

Upon stumbling onto this thread, I clicked it expecting that this would be what was used. I was very surprised with the manufactured crank instead.

[Tommy Cookers]

God i hate my last post, if the builder of this motor is reading please consider these steps;
Hayabusa 88mm bore spacing.
VW Jetta I5 88mm bore spacing.
48mm Vw big end journal?
Offset grind to 38mm big end,
10mm destroked.
Water jet cut a spacer for underneath the cylinder block to crankcase, machine to suit the stack height.

Its a start towards an even fire motor without resorting to a billet crank.

the VR5 has a 90 mm stroke and 11 deg bank offsets and end drive for power takeoff and camshaft etc
EDITED as next post says need inline 5 not VR5 - AND NB VR5 has 71 mm bore spacing
a Hayabusa 'true 5' needs a 63/65 ish stroke and inboard power takeoff etc
so the journals seem to need metal deposit (Stellite) building up of the inner flank
and (electron beam) welding etc to enable eversion of the power etc takeoff

isn't it less difficult to re-angle under heat (for 144 deg intervals) a Hayabusa crankshaft and add a 5th bit by EBW ?

Laverda made and sold inline 3 cylinder machines with 1000cc solid-mounted engines having '2-up 1-down' flat crankshafts
presumably helped as much as possible by suitable counterweighting
so can a '3-up 2-down' flat crankshaft be so bad vibrationwise as some seem to imagine ?
and can the mix of flat and crossplane that has been suggested be so bad ?

[coaster]

Tommy, VW group had 2 types of 5 cylinder, a VR6 derivative V5 and an inline 5 based on the 4 cylinder. The inline 5 has the dimensionally compatible crankshaft sharing bore spacing but little else.
Ideally, get the shortest stroke I5 crank, anneal, thin the mass on a centre lathe, grind, nitride, balance.

I cant say much about oddfiring except that a lot of development is needed for the road less travelled, maybe a good thesis for a scholar?