twin vs inline?

[Ducrappy]

http://pdmec4.mecc.unipd.it/~cos/DIN...tors/twin.html

[busa413]

Originally posted by A996S
http://pdmec4.mecc.unipd.it/~cos/DIN...tors/twin.html

What are you trying to show with the link you posted

[Ducrappy]

http://speedzilla.zeroforum.com/zerothread?id=25772
I'm not saying I'm right, I'm just saying that this is what I found. One thing to note is that there is a Harley mechanic posting in this linked thread

[busa413]

Originally posted by A996S
http://speedzilla.zeroforum.com/zerothread?id=25772
I'm not saying I'm right, I'm just saying that this is what I found. One thing to note is that there is a Harley mechanic posting in this linked thread

Sorry it sounded like I was coming off bad. I didn't mean it that way. I was wondering because I didn't see what you were talking about and didn't know if I was missing it. Wasn't trying to flame you or anything.

[Degsy]

Originally posted by busa413
Correct me if I am wrong, but the engines are a little differnt. The cyclinders are mounted at different angles on the Harley compaired to the Sport Bikes. The Cylinders on the Harley will be mounted at a 45 degree angle and on Sport bike it will be 90 degees, so this could also make a big difference in the sound.

Yes, that's what I mean by firing order, what crank position they fire at.


derek

[PatSV650]

No, he said same revolution, not "the same time".
A Harley uses a (I believe) 270º crankshaft firing interval, rice twins use a 360º interval. So what I think he meant was, they're firing while they're both in the same stroke , but, 270 degrees apart from eachother, instead of 360 which puts them basically right at one stroke away from eachother.

Hope this helps

[Ducrappy]

Originally posted by PatSV650
No, he said same revolution, not "the same time".
A Harley uses a (I believe) 270º crankshaft firing interval, rice twins use a 360º interval. So what I think he meant was, they're firing while they're both in the same stroke , but, 270 degrees apart from eachother, instead of 360 which puts them basically right at one stroke away from eachother.

Hope this helps

Thank you. thats exactly what I meant

[stoinkythepig]

Originally posted by PatSV650
No, he said same revolution, not "the same time".
A Harley uses a (I believe) 270º crankshaft firing interval, rice twins use a 360º interval. So what I think he meant was, they're firing while they're both in the same stroke , but, 270 degrees apart from eachother, instead of 360 which puts them basically right at one stroke away from eachother.

Hope this helps

I'm not 100% certain but I think Harleys use a single crank pin and with a 45 degree cylinder spacing. If so, there is no way they could have a 270 degree offset on firing. It would have to be either 45 degrees, 315 degrees or 405 degrees. Based on the sound they make, I suspect it's 45 degrees. I bet they'd run better at 315 degrees though.

[Cam_In_IL]

Originally posted by Stoneman
The analogies are for the most part correct. But there ARE high revving V-Twins that still make decent power aobve 10K. That's about where my TL-R REALLY snaps to life. I'd reckon bikes like the Mille and the RC-51 would be similar...

But those are more the exception than the rule...

Exactly. I love my TL. I love the sound, and I love the fact that I don't have to rev up to 8k before I hit the powerband. And of course I love the sound.

I think I'll take a twin over an inline 4 anyday.

[ftrain]

I Miss my TLR

BTW inline 4 and V-twins both catch on fire just as quick.

[stoinkythepig]

Originally posted by ftrain
I Miss my TLR

BTW inline 4 and V-twins both catch on fire just as quick.

Now we know the real reason you need a new roof on your garage...

[TLRMan]

Harleys do or did have one coil for both cylinders, so in a sense both plugs do fire at the same time. One where it's supposed to be and the other when it doesn't matter.

The 90 degree V twin doesn't fire evenly either, I had something written in my tech spot which is now defunct....

I'm at work now, but if you need more explanation, I will come back and write some more....

[PatSV650]

Originally posted by TLRMan
Harleys do or did have one coil for both cylinders, so in a sense both plugs do fire at the same time. One where it's supposed to be and the other when it doesn't matter.

The 90 degree V twin doesn't fire evenly either, I had something written in my tech spot which is now defunct....

I'm at work now, but if you need more explanation, I will come back and write some more....

It may not fire evenly, but, it sure as hell sounds better and feels smoother! I love the way my SV sounds with the Yoshi pipe on it! Deep, loud, and throaty!! Kinda like how I like my women!

[PatSV650]

Originally posted by stoinkythepig
I'm not 100% certain but I think Harleys use a single crank pin and with a 45 degree cylinder spacing. If so, there is no way they could have a 270 degree offset on firing. It would have to be either 45 degrees, 315 degrees or 405 degrees. Based on the sound they make, I suspect it's 45 degrees. I bet they'd run better at 315 degrees though.

You may be right, cuz, I think those numbers I gave were for the Triumph twins on their cruisers (Bonny, America, etc) but, I think you got the general idea The firing order is more like someone skipping whereas a 90 degree v-twin is more like someone running.

[Kham]

Originally posted by TLRMan
Harleys do or did have one coil for both cylinders, so in a sense both plugs do fire at the same time. One where it's supposed to be and the other when it doesn't matter.

The 90 degree V twin doesn't fire evenly either, I had something written in my tech spot which is now defunct....

I'm at work now, but if you need more explanation, I will come back and write some more....

well here's couple more ?? just answer it.

Harley emphasize the single rod in the VROD engine i think. what is so signifant about that? why does harley engine only use 45 degree?

[RandyO]

Originally posted by stoinkythepig
I'm not 100% certain but I think Harleys use a single crank pin and with a 45 degree cylinder spacing. If so, there is no way they could have a 270 degree offset on firing. It would have to be either 45 degrees, 315 degrees or 405 degrees. Based on the sound they make, I suspect it's 45 degrees. I bet they'd run better at 315 degrees though.

correct stoinky

90° twins like SV, TL, RC51, Duc etc are on a 270° offset in firing
Yamaha TDM is a parallel twin but has a 270° crank so it sounds like a 90°V Aprilla and some others are 60°V the firing timing is 300° Yamaha Virago and KTM are 75°V and Victory is 52°V

90° Vees have perfect primary balance

[RandyO]

Originally posted by Kham
well here's couple more ?? just answer it.

Harley emphasize the single rod in the VROD engine i think. what is so signifant about that? why does harley engine only use 45 degree?

VRod is not 45° like other Hardleys, 60° I think

[benVFR]

There is an awesome web page out there with wireframe diagrams of each engine type that motorcycles have, examples of which bikes have that configuration, and animations that show how the cylinders move, when the plugs fire, how the rods & cranks are connected, etc..

Unfortunately I can't find it on google anymore.

[stoinkythepig]

I generally hate loud bikes, especially cruisers and IL4 sport bikes, but 90 degree V-twins with pipes have a mellow and soulful sound that I enjoy hearing. Every time a Duc passes by, I secretly wish the rider will gas the snot out of it so I can get an earful of that sound. Noticed my dad feels the same way and we're both old and grumpy.

[beet]

is sweet sweet & i can cruise the hood @ 4:am

[02SuperHawkRdr]

Originally posted by stoinkythepig

There are some very short stroke twins out there that pull very hard on top, but they need titanium parts and such (749R, for instance) and cost an absurd amount of money ($22,000 for a bike that performs like last year's 600s...)

The 749R performs like last years' 600s? I think not. It puts down well over 100rwhp and has componentry that most Japanese 600cc repliracer-riders would die for.

It is certainly fair to point out that it costs $22k, but give credit where credit is due; that bike is sick.

[PatSV650]

I love the way my SV sounds w/ the Yoshi pipe it's got. Sounds much like a Duc or a TL. Now I just gotta go on a ride w/ someone willing to swap bikes so I can hear it from behind.

[stoinkythepig]

Originally posted by 02SuperHawkRdr
The 749R performs like last years' 600s? I think not. It puts down well over 100rwhp and has componentry that most Japanese 600cc repliracer-riders would die for.

It is certainly fair to point out that it costs $22k, but give credit where credit is due; that bike is sick.

Pure speculation on my part. Haven't seen any tests on it, but the 749S, a $15K bike, was absolutely spanked on the race track by all the top shelf 600s in the last test I read. It was not in the same league. I suspect the R model will be better than the S but I doubt it'll surpass the SS600s out there. They are tough to beat. Be nice to be proved wrong though.

For 22K, I'd keep the bikes I have and trade in my boat for something nicer...

[brewmaster]

Bump
Figured this was a good winter subject to warm the keyboards.

[R1]

Twins only for the wheelie factor alone....