Or maybe a V6...
(February 2003)

One of Honda's most experienced motorcycle engineers dropped in to Australia
for a holiday recently. Isao Yamanaka has the Blackbird and several other
bikes on his resume and Guy Allen grabbed a couple of hours with him.
You may not have met Isao Yamanaka, but there's a fair chance you've either
ridden one of his products, or know someone who has.
Yamanaka san has been involved in all sorts of weird and wonderful
machinery: relatively pedestrian stuff such as CB900 Bol d'Or and the first
of the VF V-four series, or exotica such as the eight-valve NR project.
He joined Honda as an engineer in 1974 - in the research and development
division - and these days he's a project leader. Which means he pulls
together the various aspects of a machine, such as chassis and powerplant,
to end up with a marketable whole.

It's not often you manage to corner a boffin from a Japanese factory, so
there was no hesitation when Honda rang offering the opportunity. It turns
out that Yamanaka was holidaying in the country, and had pinched a bike from
the local branch to tour over a few weeks. Typically, as a visitor, he's
managed to see more of the landscape in a matter of days than most of us get
to see in a decade, covering places such as the Great Ocean Road and Uluru
on a VFR800.
The interesting thing about that though is that, yes, he does ride bikes and
obviously enjoys the experience. During the two-or-so hours we had to chat,
his eyes lit up with obvious pleasure a few times. Once when he confessed to
a weakness for football and beer on the weekends, and otherwise when he as
on the subject of riding.

Early days
We walked through a potted history of Yamanaka's career. It seems he
progressed pretty quickly to the big stuff, working on the RCB1000 endurance
racer, plus road bikes such as the colloquially-known Roller Door, named
after the Bol d'Or 24-hour race, which the factory was rightly proud of
winning in the late seventies. He also dabbled with the CB1100R - the then
exotic road replica of the endurance racers, which became collector items
across the range.

Yamanaka noted that 500 each of four versions were eventually produced (A,
B, C, D), which Honda reckoned at the time was just enough to discourage
speculators from 'sitting' on the machines in the hope of fleecing a later
buyer. It seems the R is something of a personal favourite, mainly because
of the mail it generated from apparently enthusiastic and satisfied owners.
The VF750S - the less than spectacular shaft-drive inaugural model of
Honda's V-four series - was another Yamanaka project, and questions were
raised over why that particular engine configuration was chosen.
Yamanaka smiled at the question, and quickly pointed out the decision wasn't
his at the time. However he believes Japanese motorcycles, in the USA in
particular, tended to be stereotyped as in-line-four screamers and Honda
wanted to do something to break that mould. A number of configurations were
tried, including in-line triple, V-three and V-four laid out in both
directions in the frame.

The project team decided the VF (and now VFR) layout provided the right
"power feeling, handling, vibrations and sound". And it was something
distinctive in the market.
On the subject of engine configurations, Yamanaka expressed a somewhat
wistful note when he mentioned that, these days, there isn't much left that
hasn't been tried. From his engineering viewpoint, this takes some of the
fun out of R&D, though we assume it saves the factory some money.

NR days
Speaking of innovation, the eight-valve NR project was discussed at length.
For those not familiar with the machine, it featured oval pistons, (each
with twin conrods), running eight valves per cylinder. It was Honda's last
attempt at a four-stroke GP bike and was cynically dubbed the "never ready"
after a run of teething problems.
A 750cc variation on the machine saw some F1-style outings, with Tasmanian
Malcolm Campbell being the first rider in the world to give it a race
victory, during a Swann Series round at Calder Park in 1987.
A hideously expensive road-bike variant was produced in limited numbers, and
did not feature the wild performance that some had hoped for. Eventually the
series died out through a combination of race administrators introducing
rules which made the design uncompetitive, or banned outright, and the fact
the manufacturing costs of the powerplant were very high.
There was some hope the series might be revived for the promised
reintroduction of four-strokes to grands prix in 2002, however Yamanaka
seems to regard this as unlikely, given the weight penalty in the proposed

So why fiddle with eight valves? Yamanaka points out that there are some
strong performance benefits. Honda's research shows up some figures for
different engine configurations of equal capacity.
For example if you run a V-four eight-valve NR engine and score its
efficiency at 100, an equivalent four-valve V-eight runs at 93 per cent, a
four-valve four at 70 and five-valve four at 69. Which begged the inevitable
question: Why, in his opinion, would Yamaha persist with a five-valve
layout? He shrugged, replying, "I never worked for Yamaha."
Friction is a downside, with the NR scored at 100 a V-eight scores 130,
while the fours both score better at 83.3. and 83.7 respectively. However
Yamanaka indicated the efficiency advantages outweighed the friction loss.

The discussion of different powerplants inevitably led to the query, what is
Yamanaka's current favourite configuration?
That grin reappeared and I swear I spotted a throttle hand twitching: 
"I personally like the character of V-six (and) would like to see it in a sport
Interesting. So you've had a play with one then? Yep, and quite recently, so
far as we could judge. "I still remember I feel so excited when I ride on
(a) V-six model."
What, specifically, did he like about it? Engine character, acceleration and
that exciting feeling, is the reply. The grin is on high beam by now and the
throttle hand is definitely on the go - you could get to like this man.
Since we got that far, it was confirmed that Honda has been playing with a
V-six sport bike, although the project struck some problems with cooling and
it seemed unlikely to see production in the immediate future. The prototypes
have been 750cc in capacity and the possibility of a 1000cc version was not
ruled out.

Naturally we grilled him about other projects, most of which he was able to
express ignorance about given they were not under his control.
Since he was promoted by Honda Oz as "the father of the Blackbird", what
about the next-gen performance flagship? Is there going to be a reply to the
Hayabusa and ZX-12R?
We seemed to get sidetracked at this point, with Yamanaka saying the
Blackbird was about more than top speed. The project motto for the current
model was "the most interesting machine in the world" and he said top speed
was not the main priority. So no real answer on that one, but it's hard to
imagine Honda not working on a potential replacement.

Pot of gold
As we started to wind up, the conversation wandered on to the subject of
alternative fuels for cars and bikes. Yamanaka has no personal preference
for which way the current R&D should go, but believes there is a pot of gold
at the end of the proverbial research rainbow for the company which gets it
right. In his opinion, "The one who finds it will be the most successful for
the future."

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Tom Heron

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