Bad Engine design

[racer x]

Didn't the NR 500 stand for"never ran" .

[McRat]

Didn't the NR 500 stand for"never ran" .

AKA - Never Ready

Did a quick search, look how long the valves are.  Hard to believe it made peak power at over 20,000 rpm.

http://en.wikipedia.org/wiki/File:Ovalpiston.jpg

[WOODY@DDLLC]

Not Round! 

[johnneilson]

OK, Honda, mid 60's 5 cylinder 4/ 125cc.

turned 17 or 18krpm.

The piston, bare weighs 34g.

[octane]

OK, Honda, mid 60's 5 cylinder 4/ 125cc.

turned 17 or 18krpm.

The piston, bare weighs 34g.

That's the 1966 , RC149.
Eight speed and 32hp at a whooping 19.500rpm.


Then there was the six-cylinder 250cc, RC166, pumping out 56.8hp at 17.500rpm



....prominently raced by Mike Hailwood in the 1966 World Championship,
where he won all ten races he entered.





...now, will ya look at that:
RC166 piston/rod





Weird video, but aaaawesome sound: CLICK


.

[octane]

Some folks just can't have enough.
There's guy in California who build together TWO CBX six-cylinders = The CBX Twelve



...way to go !!!!

It runs just fine ! CLICK

BTW that guy rules ! : he build 3 Ferrari-engined bikes as well ! WOW!


I gues this thread has turned to "Brilliant Engine Design" by now....ha ha !

[octane]

I worked for John Cordona @ 4s n more many years ago and rebuilt many of these things.
what I liked was the sound, didn't think they were very fast

...compared to what ?

[octane]

That is a nice CBX Lars.  The best I have seen.  You have a right to be proud of it.

Thank you Bo.
You're too kind

In those days I was a Honda mechanic and the CBXs came into the shop for the basic stuff, like tune ups, folks that let the bike sit and needed the carbs cleaned and a new battery, low speed tip overs, etc.  Funny little engine noises, etc.  The CBXs took a long time to repair and we hardly ever charged the customers for all of the time it took to do the jobs.  We took a loss in the service department in the interest of public relations.

In my youth I was fascinated by technology and the more of it the better.  The CBX and a lot of the complicated bikes that came after it started my love affair with basic equipment.  Performance with simplicity is the most difficult combination to engineer.  Every component needs to be correct for the task at hand, in complement to the other parts, and all together must act in harmony and with balance. 

In a way I agree, but then again I also find it interesting and satisfying
to one day work on my stone-age-tech Indian, and the next day the CBX.

.

[Dean Los Angeles]

Don't forget the Suzuki RP68. 50cc (3 cu in) 3 cylinder, 14 speed gearbox, 20000 rpm 21 hp beast!

The sound of the Honda 6 cylinder 250 is one of the best in the world.

[johnneilson]

OK, Honda, mid 60's 5 cylinder 4/ 125cc.

turned 17 or 18krpm.

The piston, bare weighs 34g.

That's the 1966 , RC149.
Eight speed and 32hp at a whooping 19.500rpm.


Then there was the six-cylinder 250cc, RC166, pumping out 56.8hp at 17.500rpm



....prominently raced by Mike Hailwood in the 1966 World Championship,
where he won all ten races he entered.





...now, will ya look at that:
RC166 piston/rod





Weird video, but aaaawesome sound: CLICK


.

OK, the pic is of the RC146

1965 125cc basically a 3 cyl and 2 cyl motors cranks. The 3 cyl had 120° crank and the twin side was 180°

125 cc 4RC146 & RC148  1965 RC115 Honda
The 4RC146 is an improved version of the 2RC146, and nearly identical to it – the only external difference are the shorter exhausts of the 4RC146 (see pic 4RC146).

Power is now 30 bhp at 17,000 rpm. In actual practice, the engine hardly ever runs well, with continual Carburation and ignition problems.

Some interesting data: the piston, as usual for Honda with two compression and one oil scraper rings, weighs 34 g without the pin and rings. The pin, with a diameter of 11 mm weighs 11 g. An inlet valve has a head diameter of 14.5 mm and a stem diameter of 3.8 mm and is 74.4 mm long. Weight: 9 g. Two valve collets and the retainer weigh 1 resp. 3 g. Nobby Clarke said they used tweezers to put the Honda valve gear together.

The RC148 is the great surprise of 1965.

It is a five cylinder, in principle two and a half 50 cc twins.

Bore and stroke are 33 x 29 mm for a total capacity of 124 cc.

Drive to the camshafts is by gear train between the third and fourth cylinders. Power is 34 bhp at 20,000 rpm. There are eight speeds in the box, and the engine has wetsump lubrication.

The four exhausts of cylinders 1, 2, 4 and 5 sit in the normal place, left and right of the bike, the exhaust of cylinder 3 sweeps up and around the lefy hand side of the engine, crosses through the frame, to end up under the right leg of the rider.

Dry weight is given as 85 kg.

Sorry, this is what happens when you build 30 hp 80cc grenades. You find out what other junk has been built and don't clean up drive space.

John

[wobblywalrus]

Years ago before I got married I made my own contribution to bad design.  It was mating a Honda 450 twin to a Lycoming airplane turbocharger.  It was things I had laying around.  I had lots of time and no money.  It was interesting.   

[entropy]

The worst I ever saw is the Honda six cylinder 1000cc CBX bike.  Customers would buy those things with great expectations.  There are enough parts in each one for two normal motorcycles and tune-ups cost a fortune.  They would get hot and lose power.  Local clowns on old ratty Kawasakis and Yamahas would beat new CBXs in the street drags.  Finally Honda got smart and made a tourer out of it.  Then the got even more intelligent and quit making them.  Ah yes, the memories.     

wobbly,
I've never met you, but i already like you.

From the 350 Ducati which was my 1st bike in 1964 to the 2 LSR NA Busas i've got now, i've owned/ridden/raced lots of types of bikes.

MY 1980 CBX was BY FAR the worst POS i've owned.
Nightmare to work on, handled like sht, and contrary to lotsa folks, i didn't particularly like the way it sounded even w/the Kerker.
Karl

[DocBeech]

I am kind of curious how they were able to keep those things running without over heating or just destroying the motors at 17,500K

I have driven in a rotary engine at 15,000K only to have to break it down after a 4 hour race. Rotary engines have to be kept below 12K RPM and they are designed for high RPM but after 12K you wont get more than 100,000 miles without a rebuild. How in the world did they manage to run a piston engine that keep it cool with no oil coolers, and not just blow up one engine after another.

[octane]

..

MY 1980 CBX was BY FAR the worst POS i've owned.
Nightmare to work on

Sorry to hear you had difficulties working on it.
What particular part of working on it did you find being a "hightmare" ?

.

[racer x]

I had an Rx7 for 11 years. It had a Race beat 13 b all done up .I loved it and have aways liked the rotery engine. So far I have see 4 rotory Suzuki bikes including one on the starting line at Maxton. I have never seen one run. The one at Maxton got me all excited .After my run I got back to the starting line just in time to see it being loaded into a truck . Yup it would not start.It must be me  :-P