Shared crankpin v-twin engines

[popelli]

Hi guys,

I was wondering if there is anybody around with enough encyclopaedic knowledge to answer the following question:

Does any of the well known motorcycle manufacturers (except HD and indian) manufacture/have manufactured V-twin engines with shared crankpin and less than 90 deg. angle between cylinders?

Vincent
bsa
Matchless
JAP
Brough Superior
Royal Enfield

[Pixie]

I'm looking for the uneven "harley beat" and I've noticed that most of the japanese cruisers, even the ones with less than 90 deg. angle sound very even, which means each cylinder has its own crankpin.

Sorry but this is bollocks.
I can't think of any V-twin,including all Japanese, that doesn't share the pin.There must be at least one ,but I can't think of it.
Yamaha XVs share I have the manual here to prove it.

V-twin designers have the option to fire the cylinder in pseudo "Twingle" (not true Twingle) mode or on alternate rotations.This accounts for the different sound.
It has nothing to do with the sharing of a crank pin.

[bogan]

Sorry but this is bollocks.
I can't think of any V-twin,including all Japanese, that doesn't share the pin.There must be at least one ,but I can't think of it.
Yamaha XVs share I have the manual here to prove it.

V-twin designers have the option to fire the cylinder in pseudo "Twingle" (not true Twingle) mode or on alternate rotations.This accounts for the different sound.
It has nothing to do with the sharing of a crank pin.

my bros does, my vt does, pretty sure all the sv's also have seperate crank pins, makes for a better balanced engine. But i do agree "twingle" (which i assume is what i know as big bang firing) would make much more difference than a shared pin.

[watermellon]

Vincent
bsa
Matchless
JAP
Brough Superior
Royal Enfield

Yes, but apart from the:
Vincent
bsa
Matchless
JAP
Brough Superior
Royal Enfield

... what have the Romans ever done for us?

[Pixie]

my bros does, my vt does, pretty sure all the sv's also have seperate crank pins, makes for a better balanced engine. But i do agree "twingle" (which i assume is what i know as big bang firing) would make much more difference than a shared pin.

Bollocks again
The picture shows a disassembled SV 1000 motor.
See the single crankpin?

Attachment 208778

From:http://forum.svrider.com/showthread.php?t=88053

[bogan]

Bollocks again
The picture shows a disassembled SV 1000 motor.
See the single crankpin?

huh, so it is, would have thought that would make for really shitty engine balance. Though thinking bout it some more, a 90 degree twin would be more even as one pistons velocity is max as others is 0. Looking through them the VTR250 is also single pin 90 deg. Whereas the bros/hawk is 54deg (IIRC) and seperate pins, so thats one jappa v-twin with seperate pins anyway.

[popelli]

Yes, but apart from the:


... what have the Romans ever done for us?

and your point is ??????

[imdying]

... what have the Romans ever done for us?

Didn't they give the world cheese fondues and organised orgies?

[ellipsis]

Didn't they give the world cheese fondues and organised orgies?

..and fucking bureaucrats...

[HenryDorsetCase]

You want a Lancia V6 you do. But I suppose would be hard to get one from 1950's anyone got one lying around?

I had a look in the shed, but I must have chucked it out last time I had a clean-up. Oh well.

[jellywrestler]

My Heskeths got one effing big crankpin too

[Pixie]

huh, so it is, would have thought that would make for really shitty engine balance. Though thinking bout it some more, a 90 degree twin would be more even as one pistons velocity is max as others is 0. Looking through them the VTR250 is also single pin 90 deg. Whereas the bros/hawk is 54deg (IIRC) and seperate pins, so thats one jappa v-twin with seperate pins anyway.

It's the rare V-twin of less than 90 degrees that might go for separate pins to improve balance.(most don't)
A 90 degree V has perfect primary balance

[VS14]

Kawasaki VN900 has single pin and approx 55 deg vee. Con rods side by side (not forked).
Suzuki VS1400 has separate pins and 45 deg vee.

VN900 has uneven pattern and Harley like sound.
VS1400 has even firing pattern and sounds like a parallel twin.

Both good, but different.

Trev

[avgas]

Not a motorcycle, but I think the Bugatti Veyron engine (a work of art) also has a shared crankpin design. The comparison with my HD starts and finishes there... :-(

Not sure on how it could with a W configuration?
That would require 2 pins.

[rogson]

Suzuki's 800cc Boulevard range have a 45 degree V twin engine with two crankpins offset 45 degrees.

The US and Japan market VX800 has the same geomerty as the Boulevards while the "rest-of-the-world" model VX800 (the version sold new in NZ) has the crankpins offset 75 degrees. The US/Jap version vibrates more. Both are available in NZ (the US/Jap version as Jap imports).