[arulpeem]

This gives a simple animation of the firing sequence and the configuration. Hope this throws more light

http://www.google.co.in/imgres?imgur...ed=0CAsQsCUoAw

[alpha1]

Originally Posted by Sutripta

Good to know that cylinder timing (ie the timing relationship between cylinders) can be easily/ trivially changed.

Regards
Sutripta

Corrigendum below.

Originally Posted by dustom_99

Much better explained here. http://www.wildwestcycle.com/f_firing.html

Ok so I stand corrected.
First cylinder 0---0---1---0---
Second cylinder -1---0---0---0--
Hence final sound 01--00--10--00--
Or lets remove the "0" since we don't hear it anyway it becomes -1------1-------
So there is a slight offset in the symmetry of bangs.
This gives the characteristic Harley sound.

I have added extra dashes just to increase the resolution of time - the otto cycle remain the same, if I were to use the same methodology for my previous post the final sound pattern for previous post would be 0---0---1---1---

In my opinion the previous post firing sequence should sound more dramatic with a huge asymmetry compare the following two:
--------1---1---
-1------1-------


Wonder why such a sequence was chosen. This is undeniably the most vibration inducing configuration a twin cylinder can ever have!



http://en.wikipedia.org/wiki/Big-bang_firing_order

Also check this, you can actually change the firing pattern even though retaining the same V geometry.

[ecosport rules]

Originally Posted by alpha1

Wonder why such a sequence was chosen. This is undeniably the most vibration inducing configuration a twin cylinder can ever have!

Brand value and brand identification.

There are people who buy RE's for that sound it makes which is a craze on its own. Same applies here with the HD sound, there has to be some differentiation.

I don't think these vibrations will be so high that you'll have to ease off throttle. HD would have beefed up the insulation so that the ride has an almost vibe-free ride.

[dustom_99]

Originally Posted by ecosport rules

Brand value and brand identification.

There are people who buy RE's for that sound it makes which is a craze on its own. Same applies here with the HD sound, there has to be some differentiation.

I don't think these vibrations will be so high that you'll have to ease off throttle. HD would have beefed up the insulation so that the ride has an almost vibe-free ride.

I don't think HD thought much about brand image or unique sound when they went for 45* .
Small angle v twin has packaging benefits where you can place a very large motor in a smaller frame.
Touring range is also 45* but is relatively vibe free .
Its past few decades they have cashed in on brand and unique sound.
Also a longer gap in power stroke gives time to recover traction in racing applications.

One less crank pin has pivotal role in reliability as most of the motors fail/ start losing compression or pickup oil due to piston slap or rings breaking seal.
Since most of these start with clearance / play generated on crank pin , one less means one less potential area for such development.

[gthang]

Originally Posted by alpha1

Wonder why such a sequence was chosen.

Truth is, to save on manufacturing cost, Harley decided to go with a single pin crankshaft which necessitated such a firing order.

Guess the sound was so catchy they have decided to stay with the same since 1903.

Cheers

Ride Safe.

[dustom_99]

Originally Posted by gthang

Truth is, to save on manufacturing cost, Harley decided to go with a single pin crankshaft which necessitated such a firing order.

Guess the sound was so catchy they have decided to stay with the same since 1903.

Cheers

Ride Safe.

Who was trying to save cost in 1903 instead of coming up with a product first?
Harley & Davidson build 45 vtwin because that was the only thing they knew how to build with not many designs around to copy and make!
In those days you only made what you could conceive yourself.

They started with single cylinder and graduated to a V twin at a time around 1911. Did so to accommodate bigger motor into a frame that they had already build and used with single cylinder motorized bicycle.


Any leads how could one save on cost by making a single crank pin , instead of dual?
As single crank pin would need heavier crank than dual. Money saved on a pin would not be enough to make a bigger , more robust crank!

And Vtwin or its sound wasn't famous until most of the industry moved over to more economical in lines. which obvious happened much later than 1940-50

[Sutripta]

A V Twin (esp. if aircooled) ticks a lot of boxes when it comes to bikes. In fact a single pin 90 deg V2 has perfect first order balance.

On one hand, it is also packaging considerations which lead to oddball angles. A dual pin design can lead to better balance (on the oddball angles) on the other hand a dual pin makes the engine wider and more asymmetric:- both not desirable when packaging in a bike. Your choice as designer.

Regards
Sutripta

[gthang]

Food for thought: Ever looked at a radial aircraft engine from ~ 1900?

Cheers

Ride Safe.

[dustom_99]

Originally Posted by gthang

Food for thought: Ever looked at a radial aircraft engine from ~ 1900?

Cheers

Ride Safe.

And they told you , v twin single journal was selected for cost cutting in Harley museum?
Which company will tell you that in their own museum?

How do you assume i don't know about radial engines, are you hinting that HD guys should have put a radial in their bikes?

Did they tell you in Milwaukee how were they planning to cut cost by using a single pin?

[Samurai]

Cool it guys! Stop getting personal. - Support Team

[abhimanyu_singh]

A quick question, read it somewhere here, why would a screaming eagle exhaust void street's warranty?? isn't it a genuine accessory?

[adrena]

I've been baffled by that question forever. It'll be great if someone breaks it down for me.

[abhimanyu_singh]

Originally Posted by adrena

I've been baffled by that question forever. It'll be great if someone breaks it down for me.

buddy did you book your bike yet? HD banjara here told me that i can get the stock 2x2 iron's exhaust for the street without voiding warranty, but i doubt that, really confused here!!!

[KEN-RAND]

Originally Posted by Urban_Nomad

Net net, the only thing that bothers me is the braking. Wires et al be damned. This baby moves and moves well (is the chorus I hear in every review). I would still plonk my money on a green kwacker (a used 650 maybe) though. But for anyone looking beyond the sport bike genre; this is a mighty sweet deal

Aditya - wrt up shifts : tried clutch less shifts (as opposed to full clutch in)? May have produced better results.

And no photos of you scraping pegs? No action shots? Not done bud

I am British with 45 years of bike riding now living in Goa. I had a 40 year old Triumph 3 cyclinder 750cc which I miss. So I had a test ride on the 750 in Goa I found the following:
1. changing up if riding hard no clutch was the best way quick and smooth.
2. front brake needs a steel braided line not rubber this adds to the soft feel.
3.Seat to low for me.
4.fit and finish shows cost cutting, but in my view you get what you pay for so if I go for it some tidying up will be required.

Ken

[argchoff]

Been looking at the dyno jet test of the Street 750 on the cycleworld website. I was surprised that this Harley actually showed a 0-60MPH in 4.6 secs!!! That would just floor the 883 sportsters.
It would be good to see a comparo report of the 750 with the Bonneville.