Such an ordinary looking box....

[Speeddog]

<yawn> Meh, just another Honda part.  














Well, *that's* a bit out of the ordinary.  











Who can identify the make, model and year of production bike it fits?

[derby]

http://en.wikipedia.org/wiki/Honda_NR (1992)

[Ducatl]

Ahem, nr750 1992?

Edit: damn

Based on the cost of the bike..what's a piston like that cost?

[Scottish]

I remember when that came out. It was so cool, now the rear looks fat as hell. I wanted to answer your triv but those guys beat me.

[MotoCreations]

Instantly recognized!

Do I get any bonus points for actually having ridden a NR750 in the USA?

Note: so what are you doing with this piston? (and how much for one?)

Note 2: if you don't want the piston, I'll gladly take it for free!

[Statler]

hate to phrase it this way....but sweet package.

[lwszabo]

I remember the cycle world with that bike and the "future super Hawk" (that never came out!) That bike is still bad ass!

[BellissiMoto]

Wow, for possibly the first time in my life, I want a Honda.

[Spidey]

That f'n cool, Nick.   Good post.   

Two conrods per piston?  Mebbe I haven't looked at the guts of enough engines, but that really doesn't seem normal.  And it seems like it's a recipe for your engine to get out of balance.  And what is up with the firing order?  I assume there are journals/bearing between the conrods on that go to the opposing piston.  

[LowThudd]

That f'n cool, Nick.   Good post.    

Two conrods per piston?  Mebbe I haven't looked at the guts of enough engines, but that really doesn't seem normal.  And it seems like it's a recipe for your engine to get out of balance.  And what is up with the firing order?  I assume there are journals/bearing between the conrods on that go to the opposing piston.  

Think that's wierd? The Neander has two cranksafts and four rods to promote balance.

http://www.neander-motorcycles.com/shortversion-neu/main_en.html

[NAKID]

Think that's wierd? The Neander has two cranksafts and four rods to promote balance.

http://www.neander-motorcycles.com/shortversion-neu/main_en.html

Turbo-diesel, two crank, four rod engine in a motorcycle. Not sure you can get more unique than that!

[LowThudd]

Turbo-diesel, two crank, four rod engine in a motorcycle. Not sure you can get more unique than that!

Except the price. It's like 95k euros

[mitt]

and the NR worked.


Nice post Nick.  Now, what is the rest of the story...

mitt

[1KDS]

Turbo-diesel, two crank, four rod engine in a motorcycle. Not sure you can get more unique than that!

maybe not more unique but the motoczysz c1 motor is pretty out there

[Speeddog]

The story isn't much, the piston was just passing through, on it's way to a new home.
Only stopped long enough to get photographed.

Not mine, not for sale, and certainly wouldn't leave my possession if it was free. 

Technically....

Piston too heavy and too wide for a single rod.

The crank/rods/pistons assembly shown in Derby's pic are from the NR500 GP race engine.
Pistons are significantly different, flat on the sides.
The production piston in my pics has sides that are significantly curved.
In either case, machining the bores, pistons and rings was quite an effort I'm sure.

Both motors were essentially V-8's, just the pistons and cylinders were a bit different.
GP rules at the time (late 70's) didn't allow more than 4 cylinders, and all the bikes were 2-strokes.
Honda wanted to re-enter GP racing with a 4-stroke, but needed a V-8 to hope to be competitive with the 2-strokes.
Honda's solution was the NR.
IIRC, fundamentally all for naught; too heavy, thirsty, and maintenance intensive.
Honda caved and built 2-strokes.