Future of the Inline 4?

Did anyone read Mat oxley's column in the new RoadracingWorld? I thought it to be one of his more intersting columns. I have been yearning for something besides an inline-4 (from the Japanese so I can afford one) for a little while now. Don't get me wrong, the inline-4 is a wonderful motor and a great application, espcially in a 600cc motorcycle. And I am sure that it is easy to manufacture, produce, and service but I love the sound of the RC-45. Who wouldn't pay extra for a V-4 600cc GXV-R? If Rossi getting his ass handed to him means us getting production V-4 and more sportbikes I'm all for it. Although, the new Kawasaki is gorgeous and reminds me of a Japanese rendition of theC594 Cagiva.

Would a V motor reduce the size of the crankshaft and make a narrower motor? I never thought of the length of the crank being a detriment to an inline-4 (before reading the article).

Here's hoping we get some variation from the Japanese. I'd also be first in line to buy an inline 3 cylinder 600cc bike to go and play with all those rascals on SV650s.

 

It would definitely be a narrower motor! However, V4 makes the whole engine area very compact and tight spaced which makes working on it harder than Inline-4. I got sick of working on my V-4 400 many times.........but I love V-4 over Inline-4 and V-twins (not saying I wouldn't own one of them if I had the money).

 

I rearly make these rock solid predictions, but I'm willing to bet a V-4 or even a V-5 will never make it into any large production machines, simply because of the cost associated with developing and more importantly manufacturing that kind of a motor.

Would make a great bike though...

 

Hag,

You better tell Honda to stop producing a couple of their more famous V4 machines then.

If the public wants a V4, the companies will make them. Years ago some of the same things were being said about Honda's then radical inline 4's.

If you'll pay, they'll produce.

Tom

 

You're kidding right?

There really isn't that much of a difference. Hell they've been doing the V-4 thing for years. If the public really wants it it will be built for them. Not sure why there would be much difference in producing one type over another anymore than starting any new engine design from scratch especially considering the current computer simulation technology.

 

Actually, Hagasan has a good point. One of the biggest reason why Honda had stop producing the only mass produced V4, VFR400/RVF400, was because the cost associated in manufacturing them (they sold them at bascially the same price as the Inline-4 CBR400RR variants which makes for very small profit if any existed). Another thing is tunning. V-4 tuning is much more dificult than Inline-4. Of course, all these would change if more V-4's are being built and publics want them more and more tuners get their hands on them!

 

Sunny,

I was told years ago by a Honda rep that the V-4 was the most expensive motor that Honda ever mass-produced.

 

Somebody better tell Honda that all those VFRs in the showroom aren't production V4's. Or those ST1300s.

 

Thank you.

RCJohn, who's "they" anyways...???

p.s. There is more parts to a V-4 than to a Inline. Hence the increased cost. Your brilliance really shines through there.

 

They is Honda and Yamaha(V-Max not sportbike but lots of power). What are the additional parts that make it more expensive... just the two more heads, cams and their drives? Serious question there, not a smartassed one... explain the added cost of a V-4 compared to I-4.

My brilliance doen't shine through on motorcycle engines... mine shines through in nuclear engineering and health physics.

 

That is correct and matches what I said!

 

Ooops...... You're right! I forgot about the less performance minded VFR700/750/800 and ST1300! I thought we are only talking about performance bikes here, hence concentrating on that part..............

Correction: In the performance bikes category, VFR400/RVF400 (code named NC30/35) are the only mass produced Honda V4 sold at competitive price range (basically little to no price difference when compared to the Inline-4 400s) and was too expensive to produce which lead to a production cease (profit margin not attractive)............ VFR750/RVF750 (code names RC30/45) were limited productions to satify the WSB requirement and sold at high retail prices.

 

Now wait a minute. Since when does a "performance" motor cost so much more than the "production" version? Or have a different number of parts? Granted there may be a difference in finishing of the parts or some tuning variations including different cams or heads, but be serious, do really think it costs that much more to make a VFR800 motor into a "performance" motor?

Motorcycle manufacturers compared to auto manufacturers are minisule size businesses. Yet, motorcycle manufacturers can produce many many models with widely varying frame, bodywork and engine configurations and STILL be hugely profitable.

If V4's win, they'll be in production "performance" bikes and on the show room floors. If they don't, they won't.

Tom

 

They are saying there are more parts in a V-4 as compared to an I-4. A race V-4 isn't necessarily going to have more parts than the same production V-4 and in most cases will have less to save weight.

Actually there is a huge difference in turning any production motor into a race competitive motor regarless of configuration. Materials being a huge part. VFR being a good example. The race version would need to rev much quicker and much higher and with much more compression... all meaning lots of money. Then in factory form it is rare unobtanium parts. Although alot of the expense is a play on numbers. If you can't sell enough to offset R&D then you can say that it is the most expensive design. Once the R&D is done and the tooling is set then there wouldn't be much difference. I would guess that there is more labor involved with the V-4 since there apparently is alot more parts. haven't figured out how many yet.

Just to give an example of a more limited production race motor...

a Muzzy Raptor 835cc producing about 155rwhp costs in the neighborhood of $15K. I don't remember the actual number but it was expensive. Not many made, lots of work to lighten the motor... quite a bit of magnesium and titanium and not enough sold to offset costs. This isn't really a good comparison to the discussion but should help a little.

 

None of these arguments about the V-4 hold up...there are/have been lots of mass produced V-4 motors (no, not all sportbikes) with varying degrees of success.

Yamaha has the V-MAx and Venture, Suzuki made the Madura (shudder), and Honda has made about 70 zillion of them (Interceptors dating back to 83, Sabres, Magnas, STs). I'm not saying they aren't more expensive to make, I'm just saying that it's pretty clear that the V-4 layout does not preclude mass production, performance bikes or otherwise.

Besides, if Honda came out with a v-5 RCV streetbike for $17,000 do you doubt that they's sell about 50 bazillion of them? Hell, people have inexplicably been buying $15,000 Ducatis for a decade or more. I mean ya they look _awesome_, and they work, but people buy the coolness, not the performance for the most part. I think even the most hardened Ducatisti would admit that an R1 with $5000 in work done to it will surpass the performance of a $15,000 Ducati in every quantifiable way, and yet they sell well.

The point is that the Honda would have both cache and incredible performance (and Honda reliability). Hotcakes I tell ya, hotcakes.

 

As far as production V4's - look up the 1939 AJS - 500cc V4.

 

Okay, I think we are getting our definitions mixed up here. So far we have mentioned "production" motors, "performance" motors and, RCjohn has mentioned what I would refer to as a "racing" motor.

Production V4's are being produced and sold in the showrooms every day and have been for a long time.

Performance V4's, which is what I think we are pontificating here, are not on the showroom floors....yet. If they win this season you'll see them in the dealerships. I agree with the RRW article; this is a critical year.

Racing V4's are unobtanium right now. But wait, they'll gradually be come available.

I predict that a European company like Ducati or Aprilia will be the first to make a big commitment to a V4 motor in their production line with Suzuki close behind. Suzuki is not going to sit back and let themselves be spanked in MotoGP for long. There's too much racing history there. There inline 4 has done zero in that venue and they need a radical change to get back on the winning track.

Tom

 

V4's are more expensive to manufacture because you have to make TWO cylinder banks intersect with the crank centerline, rather than just one. Plus you have another cylinder head, camshafts, and a more complex drive mechanism for them. But the big one is the increased complexity in machining the engines due to the V layout.

 

I think WERA needs to schedule a visit to an engine manufacturing plant. With the advent of CNC (computer numerical control) machinery anything can be machined easily and quickly. As far as V configurations go, the auto industry has been doing them forever and has solved nearly all of the manufacturing problems. The incremental cost between an inline and a V4 are slight.

The incremental costs between a V2 and V4 configuration are insignificant (just look at the SV650) and V2's are made by the thousands every day.

Tom

 

I just don't see how any of that is that difficult with current technology and computer simulation and CAD. Making two cylinder banks intersect with the crank is just can't be that difficult these days. I agree that the added head and cam drive mechanisms is a factor but damn how big of a factor can that be? Let's face it, if Yamaha felt it necessary they could change the drive output on a V-Max and put that engine in a sportbike and not for a huge investment in R&D. They just don't see a need is my guess... they sell R1s just fine. My guess is weight of a V-4 compared to the same hp I-4 is the big issue. Weight savings is expensive so maybe that drives alot of the added expense.

It will be interesting to see where it goes. Something is a problem or Honda would have a V-4 in superbike racing. Can't be just money with Honda's pocketbook.