Engine Tech stuff

can someone explain the firing sequence of triples and v5's?

thanks in advance

mero

 

yes



but I've never met him

 

Spark, spark, spark.
Or
Spark, spark, spark, spark,spark.

Happy to help.

Aaron
ZX6R

 

Ahhh, that makes sense - the triples run even firing orders, but
the v-fives run that last cylinder a little closer than the
rest... Thats must be why they sound that way...

Actually, I seem to remember reading an article where Jeremy
Burgess (?) - Rossis crew chief explaining that even _he_ doesn't
know stuff that detailed about the motor - Honda fly a bunch of
them out to each race meeting, and they just bolt them in and go
win races - no opening up needed (or indeed allowed).

big

 

My old points model mach111 triple used to go spark, spark, umm, spark, ummmm, spk, sp, sp, ****!!
(It may not have made that last noise but I'm sure I heard it!)

 

perhaps i should clarify ...

how do they cylinders fire when you have a 4 stroke cycle? do they have a
blank firing cycle (similar to a twin)?

a twin goes: spark, nothing, spark, nothing
an inline 4 goes: spark, spark, spark spark

does that mean a triple goes: spark, spark, spark, nothing?
and a five goes: spark/spark, spark, spark, spark?

 

I don't know how the triples and V5 engines work, but your underlying
assumption that when 1 cyl is at TDC all of the other cylinders will be either
at TDC or TBC may be flawed for bikes which have an odd number of cylinders
(and even for 4 cyl 2 stroke GP bikes... the Honda (and Yamaha?) "Big Bang"
engines had a rather unusual firing sequence.. something like nothing nothing
nothing nothing nothing nothing nothing spark spark spark spark).

Nev..
'02 CBR1100XX #2

 

Nah, that's the timing advancer kicking in on the fifth spark.

 

))))
You bastards !!
That thread cost me another keyboard, the other 2 are still drying out,
upside down over the heating-vents.
....and coffee is NOT on special this week!


Thanks guys
pete (still trying to fire in ANY order)

 

"Nev.." wrote

They had the firing sequence of two twins running synchronously. Two
cylinders fire together, then the other two 180º later, then 540º
later, the first two again.

Theo

 

put the boards in the dish washer on gentle cycle cool.

 

"Intact Kneeslider" wrote

Duh! Bloody two-smokes 180º later.

Theo

 

No it doesn't. It only gives you an even firing order. The 955 Triumph has a
balance shaft.

And a balance shaft.

Doug Cox.
Work to ride, Ride to work...

 

Depending on how you cut the cams and trigger the ignition, as the rest of
my example demonstrates.

To smooth out the secondary vibration ahead of almost anything else. An even
phase crank gets the sum of the momenta due to the primary motion of the
pistons near to zero. The balance shaft compensates for the secondary motion
(jargon used to hide my not having put equation to paper to convince myself
of how the whole show works and just how big the correction ends up needing
to be)

All 5 of my inline fours have had balance shafts, too, even the little one
that revved to 19 grand.

I remember hearing a story about someone pulling the balance shaft out of
their Triumph just to see what would happen... it'd be useful if I
remembered what the results were, too...

Isn't that actually one of the big things with top-flight race motors; they
pull the balance shafts out of them and the engine builder compensates as
best he can with what's left and the rider gets told to put up with the
rest. I distinctly remember reading about Andrew Hallam or one of the other
Melbourne tuners commenting on how they race-prep a GSX-R1000 and they
specifically stated that they ditch the balance shaft, not so much to get
back the couple of hp it takes to spin, but because they don't want to risk
having it fly apart; as they put it, it's a couple of kg of unbalanced metal
whizzing around at anything up to 25,000rpm thanks to the raised redlines of
racebikes.

 

Does it really ? And which twins and inline 4s have these characteristics

JL
(hint, do you know the difference between a 2 stroke and a 4 stroke ?)

 

Please do... it'll be appreciated...

 

To dull it down, a 4 cyl motor would be running with the cylenders offset 90' from each other,
The order of the offset is a matter we dont need to enter into here. but but but

oh hell i see where your coming from, i'll shut the hell up and read other replies.

Mike.S

 

'Ere we go

http://www.mecc.unipd.it/~cos/DINAMOTO/indexmoto.html

Got some great stuff here. And given you speak wog you can make more sense out
of some of them than my scratchy italian allowed me to.

JL

 

In a four stroke motor any given cylinder will fire every second revolution.
In most circumstances this means that all cylinders will fire in every two
revolutions of the motor or a multiple there of. The rest just involves
offsets in the crank to even everything out....

 

yes ebberytin fire in 2 revolutions mon...crank pins are offset to 3/360 or
5/360 etc, cam rotates at 1/2 crank speed and bumps are arranged according
to required valve timing and cylinder offset