- Joined
- Jun 26, 2007
- Messages
- 9,515
- Location
- Norah Head
Yeah but that was a 72 or 74? tweren't no 90!! ..... so again I say ...... where is all this "hocum" suddenly coming from!?? and why?
How about ..... when we see a 90 .... we'll discuss it
Help Support MotoGP Forum:
Yeah but that was a 72 or 74? tweren't no 90!! ..... so again I say ...... where is all this "hocum" suddenly coming from!?? and why?
How about ..... when we see a 90 .... we'll discuss it
Yeah but that was a 72 or 74? tweren't no 90!! ..... so again I say ...... where is all this "hocum" suddenly coming from!?? and why?
How about ..... when we see a 90 .... we'll discuss it
The picture posted early in that thread by j4rno was of the honda 800 V4 engine, undoubtedly a narrower angle V, he was suggesting it might be hard to tell from a quick glance. I don't think any pictures of the new engine are extant, and if they were they would be being widely published I would think.
David says he has seen one, and it looks like a 90 degree V4 is the bottom line, and I guess it is fair enough for you to wait to see if he is right. We did speculate that if honda want to have their new road sportsbike, and hence their wsbk, and their motogp bike closely related they don't seem keen on balance shafts particularly for road bikes.
- Joined
- Jun 26, 2007
- Messages
- 9,515
- Location
- Norah Head
Thats cos Honda know whats the go and narrowed their V and tipped it back around the centroid of the bike ....... ergo most of problem solved. Why Balance something that has the imbalance at a point that does not matter?
PS. Thats a lot of speculation you are running there!!! based on one persons "coulda maybe possibly is ... "!!
And why!! thats what gets me ..... why are folk so ready to jump on that once rejected bandwagon again!!
- Joined
- Apr 4, 2011
- Messages
- 636
- Location
- Gold Coast
- Joined
- Jun 26, 2007
- Messages
- 9,515
- Location
- Norah Head
Cred over Ducati?......
That's exactly what went through my head haha
ANd they'll put out an ad
with Nakamoto starting a stopwatch
and some flurried design work happening, then a blur of machining
then Nakamoto stopping the stopwatch .......
and it says ........ 1 minute 20 seconds
- Joined
- Apr 4, 2011
- Messages
- 636
- Location
- Gold Coast
ANd they'll put out an ad
with Nakamoto starting a stopwatch
and some flurried design work happening, then a blur of machining
then Nakamoto stopping the stopwatch .......
and it says ........ 1 minute 20 seconds
Hahaha, that would be ...... rude!
Thats cos Honda know whats the go and narrowed their V and tipped it back around the centroid of the bike ....... ergo most of problem solved. Why Balance something that has the imbalance at a point that does not matter?
PS. Thats a lot of speculation you are running there!!! based on one persons "coulda maybe possibly is ... "!!
And why!! thats what gets me ..... why are folk so ready to jump on that once rejected bandwagon again!!
Again, David says he has seen it and it is a 90 degree V. His observation may be wrong, but I don't think it qualifies as speculation. Honda have directly announced they are producing a new sports bike with a V4 which will be the basis of their new wsbk contender, and which will be related to/influenced by their motogp bike, also not speculation.
Correct me if I am wrong, as you and everyone else know I am no engineer, but I thought that narrower angle V4s mostly seem to require balance shafts, for reasons other than your hypothesis concerning horizontally aligned cylinders in L4/90 degree V4 engines. Aprilia's road -bike with a narrow angle V4 has a balance shaft, not speculation. Honda's only ever bigbore production bike that is a narrow angle V4, the VFR 1200, is specifically engineered to not require a balance shaft, not speculation. Their previous race bike related rc30 and rc45 bikes had 90 degree v4s, not speculation. Honda have said that an advantage of going V5 for the 990 gp bike was that it did not require a balance shaft, again not speculation.
Speculation is what we do on here, but any speculation beyond the preceding is admittedly disproved if you tell me from your admittedly greatly superior engineering knowledge that there is no reason for narrow angle V4 bike engines to require balance shafts, and provide examples of bikes which don't have them.
Your hypothesis concerning the L4 ducati engine has always seemed to have merit in my inexpert view. I don't think you can say that it is proved though; what is your evidence other than ducati not being able to win more than one championship against yamaha and honda, which conceivably could be related to factors other than their L4 engine architecture. Honda have only won one championship with a narrow angle V4 four stroke if it comes to that.
I realise that (only from looking up about the VFR1200), but do you want constraints on the firing order, crank pin angles or whatever on an engine you want to race?, or would such measures be sufficient to cope with an engine in race tune?, not that I would know myself.
It is a balancing act (ahem)
If you want big-bang, crossplane, etc., it will dictate the construction of the crank, the crank web and inherent primary balance, which will dictate whether you need a balance shaft or not.
No-one wants a balance shaft if they can afford it - weight, complexity, losses through additional friction.
If you want big-bang, crossplane, etc., it will dictate the construction of the crank, the crank web and inherent primary balance, which will dictate whether you need a balance shaft or not.
No-one wants a balance shaft if they can afford it - weight, complexity, losses through additional friction.
- Joined
- Feb 20, 2009
- Messages
- 1,180
- Location
- New Orleans
It isn't that the 90 V4 isn't capable it just isn't optimal at the level the bikes are at now, the more you can move an engine around the better, for adjustment purposes. You can see how difficult it's been for Ducati and all the modifications they've had to make to other parts of the bike to move the engine around. It's the same problem the mono chassis has, any adjustment requires changes to every part of the bike and that makes any changes happen at a slow pace because of all the extra work to move something just a few mm. The bike is still .... by the way.
I am aware that is the accepted wisdom, but the question is whether honda agree since david emmett seems to believe they are bringing in a 90 degree V4, having seen the device . My speculation is that if it is the case they may not see that engine configuration as such a problem, and they do seem to not like balance shafts, which I am fairly sure their recent narrow angle V4 and suzuki's V4 have/had. I don't really see the 4 stroke era as being an endorsement of narrow angle V4s if you want to correlate results only to engine configuration btw, with the count of world championships 5 (soon to be 6) by I 4s, 3 by 70 something degree V5s, 1 by an L4 and 1 by a narrow angle V4. I am not sure the single 2011 championship proved hrc's mass centralisation engineering theory either, particularly for those of us who think casey stoner had a little to do with it.
If david is wrong or was joking, I will stop teasing barry about it.
Ducati's problem is exacerbated by the other role the top chassis had - that of airbox. That, as much as the L-layout, meant they had less options in engine placement. Using a perimeter frame, such as Hondas and Yamahas, means that is no longer an issue.
Honda have stated the new sports bike will not be the basis for a CRT-type effort, but will be the future for WSBK. If they want a 90deg V4 for the road, they will make it work.
- Joined
- Feb 20, 2009
- Messages
- 1,180
- Location
- New Orleans
That's my point exactly, the thing just doesn't lend itself to being easy to work on and develop. It could be the greatest thing since sliced bread but getting it there is going to take a tremendous amount of work.
- Joined
- Feb 20, 2009
- Messages
- 1,180
- Location
- New Orleans
Well all other things being equal, displacement is displacement. Yamaha like the I4 because of the handling advantages, it's easy to put that engine where they want and have a short wheelbase. The narrow angle V4 is trying to mimic that by reducing the width(from front to back) of the engine while still having good low end tq of the V engine. I have no clue what is up with David and it kind of bothers me that the way he posts here, his site, and twitter are so different. He may have also put his new discovery on his site or twitter, but I haven't seen that he did and that makes me question his motives.
V's don't give inherently better torque - that is a function of stroke. Longer stroke, more turning moment on the crank.
V's are 'usually' more torquey because a 1000cc V-twin has much longer stroke than a 1000cc I4. A V4 of 81mm bore has the same stroke to an I4 with 81mm bore and thus, the same torque.
Hardleys have a lot of torque and not much power - long stroke, slow piston speed. A GSXR600RR has a lot of power, not much torque - short stroke, high piston speed.
A 1600cc Harley can have a 5" stroke, a GSXR600RR has 1.78" stroke. Try undoing a bolt while holding your spanner 2" from the bolt...
That is more or less my point, that if they want a new V4 for their next wsbk contender they may be going 90 degree V4 because they don't appear to like balance shafts, and may see this as a bigger issue than the theoretical packaging problems of the L4 architecture, in addition to which their previous RC30 and RC45 road bikes which were the basis of previous race bikes and to which they have said they wish to hark back were 90 degree V4s. The 990 engine even from my ignorant perspective was obviously a brilliant piece of engineering, and the V5 architecture like a 90 degree V4 gave the engine intrinsic balance, allowing a narrow angle V without the need for a balance shaft ; I knew at least these things without recourse to google. There seems to be a fair amount of secrecy about the Honda 800 and 1000 gp V4s but I think the 800 did have a balance shaft, and I assume but don't know that it was a development of the narrow angle V5.
I totally agree that if honda do go 90 degree V4 they are likely to make it work.
I don't believe that just because a view is prevalent currently that it is necessarily correct either, and views regarding these engines have changed before; I recall some suggestion that valentino himself was pushing for yamaha to change to a V engine when ducati looked to have superiority in 2007. No doubt that the limited engine rule presented major difficulties with ducati's integrated chassis design regardless of whether it was flawed anyway though.
(EDIT RC213V is the current honda 1000 motogp bike of course, I should have actually read the start of the other thread. I don't think anyone knows what the V angle of that engine is though, and it would still surprise me a little if honda put out a narrow angle V4 roadbike to be the basis of their superbike contender).
Interesting interview with Preziosi:
http://www.gpone.com/index.php/en/201209148199/Preziosi-the-development-truth.html
http://www.gpone.com/index.php/en/201209148199/Preziosi-the-development-truth.html
