The V4 RC45 is NOT a Big Bang motor in stock form...no matter what you or Crash implies.
I just want to kiss OB's bald head... he sticks to his guns no matter what the world says...
Quote Bike 2002
"Honda V-fours, both street and racing, have had both 180º and 360º crank
layouts. But the flat drone of the RC45 made it unmistakably a 360 big
banger. That's principally why that V-four gem was renowned not so much
for its sheer power, but for being easy to set up and, above all, for its
ability to find grip out of turns."
I just want to kiss OB's bald head... he sticks to his guns no matter what the world says...
I can't believe I just read that, lol Yes, that ranks right up there with your earlier comment about me having an open mind stashed away somewhere in my cranium....
If you had ANY idea about physics or what the world says, you would have awakened from your V4-induced heresy a loooooooooooooooooooooooong time ago.
Seriously Larry, you need help. I mean really, really need the help of a good psychologist/psychiatrist if you believe even 1% of what you write on this forum.......
Negative. The term Big Bang refers to the simultaneous firing of multiple cylinders either at exactly the same time, or very close together.
True... but a V2 and a V4 with a 360º crank can produce the big bang
effect... and thus be consider Big Bangers when speaking in a 4 stroke
discussion...
Quote Neal Spalding MotoGp Tech:
"Big V Twins have always been big bang. It is worth noting that Ducati
ruled superbike racing with a 90º V-twin, revving to around 13,000
rpms. It's power pulse hit the tire only twice every four-stroke
cycle, on that basis, it seems fair to say that V-Twins have always
had the big bang effect."
I can't believe I just read that, lol Yes, that ranks right up there with your earlier comment about me having an open mind stashed away somewhere in my cranium....
If you had ANY idea about physics or what the world says, you would have awakened from your V4-induced heresy a loooooooooooooooooooooooong time ago.
Seriously Larry, you need help. I mean really, really need the help of a good psychologist/psychiatrist if you believe even 1% of what you write on this forum.......
Sit upon my knee mikstr and tell me all your problems...
True... but a V2 and a V4 with a 360º crank can produce the big bang
effect... and thus be consider Big Bangers when speaking in a 4 stroke
discussion...
Quote Neal Spalding MotoGp Tech:
"Big V Twins have always been big bang. It is worth noting that Ducati
ruled superbike racing with a 90º V-twin, revving to around 13,000
rpms. It's power pulse hit the tire only twice every four-stroke
cycle, on that basis, it seems fair to say that V-Twins have always
had the big bang effect."
True, the 360 V4 CAN become a Big Bang...it's just that the RC45 isn't...and isn't ANYTHING like the V-twin in terms of "bangs"
__________________ Old Baldy / WWBO #451
Ducati 996
Kawasaki KLR 650 '02
Kawasaki KLR650 '06 OB's Blog
if the cylinders fired in pairs together you might be onto something, but no dice. I love ya man, but you're gunna have to try a bit harder. and somebody correct me if I'm wrong here, but didn't Ducati actualy do this on the original 990 gp bike and called it the "twin pulse"
So how is it possible for the 360º V2 to be called a big bang and not the 360º V4??? after all the V4 is just a pair of V2 working in concert...
Larry,
You are really worrying me. The term big bang refers to 2 (or more) cylinders igniting the cylinder charge at or near the same time. It does not just mean the crankpins are inline. Though the crankpins usually have to be inline for this to happen ...
From Old Baldy's post (I think the 2nd in this thread) here is the RC30/45's firing order:
90Deg V4 360 crank (RC30/45 etc) BIG BANG
000----090----180----270----360----090----180----270----360
000----090----180----270----360----450----540----630----720
-1&3---------------------------------2&4-------------------1&3-
To make a RC30/45 engine actually a big bang engine would require new camshafts and ignition modules (unless they are like many bike engines and fire every revolution even though only every second revolution causes combustion). You would probably break the crank.
Now returning also to twins. Unless both cylinders 1 and 2 fire at the same time in say a parellel twin it is impossible for a twin engine to be a true big bang engine. Sure if the engine is the same size as a v4 each combustion bang is going to be bigger than the v4, but that does not make it a big bang engine.
Referring to your quote:
Quote:
Originally Posted by Neal Spalding MotoGp Tech:
"Big V Twins have always been big bang. It is worth noting that Ducati
ruled superbike racing with a 90º V-twin, revving to around 13,000
rpms. It's power pulse hit the tire only twice every four-stroke
cycle, on that basis, it seems fair to say that V-Twins have always
had the big bang effect."
He is trying to say they achieved the same effect as a proper big bang v4 by allowing the tyre to relax between power pulses. I also said in my earlier post that if Ducati really thought the v4 big bang was that good ... why don't they just race a twin (http://www.speedzilla.com/forums/587252-post16.html).
I guess in the end a big bang v4 is the ultimate twin because it has the advantages of a normal v4 in volumetric efficiency caused by more small cylinders and it has a shorter stroke allowing even high revs, but as Ducati have already found out they are hard to keep together thus they have to stagger the firing order, thus not true big bangs anymore ... but I bet the rear tyre likes this staggering because once it's gripped it has a longer but lower torque pull to make use of. Can you please convert your RC45 to a true big bang please ... that will be interesting .
ps: Honda used to race big bang v8 engines in CART as torque was more important apparently ... it's definitely not just a v4 concept.
Pete
__________________
'97 Suzuki GS500E
'90 Suzuki GN250 - Sold 57000 km's later. Cost less than 12c per km to run ...
Grumpy Kiwi.
Why fly when ya can make a lot of noise
Giving it a go at flogging the dead horse huh PSk..... have fun! I suggest you set more reasonable and achievable goals for yourself, you know, like moving the Rock of Gibraltar using concentration only,...., you`ll end up a lot less frustrated, ol
You are really worrying me. The term big bang refers to 2 (or more) cylinders igniting the cylinder charge at or near the same time. It does not just mean the crankpins are inline. Though the crankpins usually have to be inline for this to happen ...
From Old Baldy's post (I think the 2nd in this thread) here is the RC30/45's firing order:
90Deg V4 360 crank (RC30/45 etc) BIG BANG
000----090----180----270----360----090----180----270----360
000----090----180----270----360----450----540----630----720
-1&3---------------------------------2&4-------------------1&3-
To make a RC30/45 engine actually a big bang engine would require new camshafts and ignition modules (unless they are like many bike engines and fire every revolution even though only every second revolution causes combustion). You would probably break the crank.
Now returning also to twins. Unless both cylinders 1 and 2 fire at the same time in say a parellel twin it is impossible for a twin engine to be a true big bang engine. Sure if the engine is the same size as a v4 each combustion bang is going to be bigger than the v4, but that does not make it a big bang engine.
Referring to your quote:
He is trying to say they achieved the same effect as a proper big bang v4 by allowing the tyre to relax between power pulses. I also said in my earlier post that if Ducati really thought the v4 big bang was that good ... why don't they just race a twin (http://www.speedzilla.com/forums/587252-post16.html).
I guess in the end a big bang v4 is the ultimate twin because it has the advantages of a normal v4 in volumetric efficiency caused by more small cylinders and it has a shorter stroke allowing even high revs, but as Ducati have already found out they are hard to keep together thus they have to stagger the firing order, thus not true big bangs anymore ... but I bet the rear tyre likes this staggering because once it's gripped it has a longer but lower torque pull to make use of. Can you please convert your RC45 to a true big bang please ... that will be interesting .
ps: Honda used to race big bang v8 engines in CART as torque was more important apparently ... it's definitely not just a v4 concept.
Pete
Thanks Pete for the rational reply without personal attacks... but why
would I want to convert Mr.RC45 to your version of a big bang if it will
probably break the crank???
May I please stick with HRC's version of the Big Bang which provides the
same effect allowing the tyre to relax between power pulses??? After all it
was HRC's 4 stroke firing order of the RVF750 that born the NSR500 2
stroke Big Bang... it wasn't the NSR's big bang firing order that born the
RVF's firing order... HRC named the RVF's 360º crank Big Bang when the
NSR was still a 180º screamer crank...
So inclusion the RC45's crank is phased big bang... The RC45 dones Big
Bang... the RC45 power pules are relax Big Bang... for all practical purposes
HRC is right... the RC45 is indeed Big Bang and so is the new Ducati if the
crank pins are inline as you correctly stated...
RC45's 360º V4 Big Bang crank or Ducati's new V4 Big Bang crank phased 360º...
[youtube]http://www.youtube.com/watch?v=gxWj-2MHxUQ[/youtube]
Larry, it's closer to Big Bang than the 180 V4, but the RC45 does not fire its cylinders together, or anything closer than 90 degrees apart, and never has a rest period longer than 270 degrees.
As Pete (and I) mentioned earlier..it would be a true Big Bang if both pairs or even one pair of cylinders from each bank fired their combustion at the same time instead of alternating as they do. Remember, even though the 360 V4 LOOKS like 2 V-tiwns next to each other, they are actually 360 degree out of phase from each other and alternate their combustion cycles instead of firing together....so like I said before, it could be considered a "virtual" Big Bang, if you like.
__________________ Old Baldy / WWBO #451
Ducati 996
Kawasaki KLR 650 '02
Kawasaki KLR650 '06 OB's Blog
I don't believe the current so called screamer Ducati v4 is a 180 degree v4, I believe it is exactly the same as a RC45 with the crankpins inline, but as Old Baldy says each pair of cylinders fire alternatedly (is that a word?).
And yes Old Baldy's first post supports the above:
90Deg V4 70 crank (Desmocedici - not Big Bang)
000----090----180------290----020--090----180----270----360
000----090----180------290----380--450----540----630----720
-1-------4---------------3------2-------------------------1-
Ducati are trying to rest the rear tyre even more by changing their firing order to a true big bang (allowing for slight offset to hold the engine together).
Pete
__________________
'97 Suzuki GS500E
'90 Suzuki GN250 - Sold 57000 km's later. Cost less than 12c per km to run ...
Grumpy Kiwi.
Why fly when ya can make a lot of noise
Larry, it's closer to Big Bang than the 180 V4, but the RC45 does not fire its cylinders together, or anything closer than 90 degrees apart, and never has a rest period longer than 270 degrees.
As Pete (and I) mentioned earlier..it would be a true Big Bang if both pairs or even one pair of cylinders from each bank fired their combustion at the same time instead of alternating as they do. Remember, even though the 360 V4 LOOKS like 2 V-tiwns next to each other, they are actually 360 degree out of phase from each other and alternate their combustion cycles instead of firing together....so like I said before, it could be considered a "virtual" Big Bang, if you like.
Barry... no the RC45 does not fire its cylinders together... we established
the fact that is not a good idea... it would probably break the crank not to
mention it would empty the air box at the rate of 2 cylinders per firing
instead of 1... and the RC45 is not a "virtual" Big Bang... I think we
established the fact it's the original RVF Big Bang that actually born the
NSR500 Big Bang of the 90s...
It possible that a 360º Big Bang Ducati with a firing order the same as the
RC30/RC45 is what Casey and Nicky are raving about... after all it's what a
bunch of us Honda race bred V4 nuts have been raving about for years...
I don't believe the current so called screamer Ducati v4 is a 180 degree v4, I believe it is exactly the same as a RC45 with the crankpins inline, but as Old Baldy says each pair of cylinders fire alternatedly (is that a word?).
I agree Pete... the 180º V4 animation I found was only to demo the
possibilities of a V4 screamer and it is actually a VFR 800... it's not Ducati...
I also believe the new Ducati crank pins are the same as the RC45... all on the same plane...
[/quote]
I think we
established the fact it's the original RVF Big Bang that actually born the
NSR500 Big Bang of the 90s...
Larry, no the RC45/RC30 360 V4 is nothing like the 2-stroke big-bang V4, which fired multiple cylinders at the same time. On the other hand, any four-stroke is going to provide a much longer rest period, due to the 720 degree combustion cycle....
You should remember that there have been many real Big Bang variations tried over the years, including the early Ducati V-4 Twin-Pulse Desmocedici version, which fired both pistons on each bank at the same time, effectively firing exactly like a V-twin, but with the shorter stroke to allow the RPMs necessary for big power, and the smaller, better shaped combustion chamber of the 4 cylinder, and the much greater valve seat perimeter for very good flow at low valve openings.
BUT...this real Big Bang engine was eventually discarded for the special offset crank arrangement of the later 990, which had a 20-degree offset crank pins to give a real long, 340 degree "rest" period betwen each full combustion cycle, vs. the "normal" 360 V4 timing which offers only a 270 degree "rest" period, and the even longer 450 degree "rest" period of a normal 90 V-twin.
Here is an interview on the early Big Bang Desmocedici (which was dropped by Ducati)
.
Linear Mode
