Bad Engine design

[Gu11ett]

I rode a 1979 CBX with a turbo for awhile. Smooth, lots of power, and a hoot to ride.

[gearheadeh]

I used to drag race against one way back when they were new. It was a quick high reving machine that was fun to race against and beat with my dragster   

[McRat]

I remember reading Cycle's review/analysis of the CBX when it came out.
One thing that stuck out was the Honda Test Lab.

They ran it at sustained WOT with no rev limiter and at about 20 minutes, the studs finally started to pull out of the case.  

It was a virtually indestructable engine they said.

IIRC, it was priced too high for the market, and Suzuki offering was quicker in the 1/4mi.  Bikes lived and died by mag ET's (which a mear mortal could never duplicate, they were usually done by Pee Wee Gleason, no relation)

[McRat]

Probably-Not-Politically-Correct -

Gotta give Harley-Davidson an HM as well.  Knucklehead is not just the nickname of a head config ...

No room for an intake manifold / carb, cronic overheating of rear cyl, siamese rods, hemi gone mad, widest 2 cyl with the exception of BMW, hard to get equal exh, agricultural technology.

Hotshoes made HD's fast not BECAUSE of the design, but in SPITE of the design.

You can tell how fast a Harley is by how little OEM content is still present.

I had a '79? and it was the highest maintenance bike I ever owned.

[mtkawboy]

The AMF Harley years were junk. The later EVO & Twin Cam motors are light years better. My 95 Fatboy has been 100% trouble free. The biggest downside is the Harley tax, about $2000 to make it run like it should have when you bought it. If I have to explain it, you wouldnt understand it.

[Dean Los Angeles]

Yamaha's first four stroke 750 twin. Six head gasket redesigns. Also leaked oil. Where? Through the porous castings.

Yamaha ended up replacing all of the engines. I went to Yamaha's headquarters in Buena Park. There was a huge dumpster full of engines. Quite a sight.

[turborick]

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

Woobly, my man, allow me to completely and utterly disagree

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

Yeah, sure: it's a SIX-cylinder...and a ( for the time ) sophisticated one

and tune-ups cost a fortune.

Doesn't make it a bad engine design.
Just makes it an engine design way more complicated and sophisticated than
was the norm at the time.
It's like saying that a Bugatti Veyron is a 'bad design', just because it's mindblowingly expensive
to service.
The CBX was the Bugatti Veyron of motorcycles of the time.
Any drunk child could adjust the valves on, let's say, a HD,
but it took a bit more brainpower ,patience, knowledge and finesse
to adjust the 24 (!) valves of the CBX...with SHIMS (!) that is.
Not to mention sync-ing the 6 carbs to perfection.
But HEEEY; that's what it takes to run a 'sophisticated' six cylinder wonder-machine.

Of cause the traditionalists hated it.

They would get hot and lose power.

Can't say that it was NOT the case, but I've never heard of it,
neither in all the road tests done at the time ( I have a bunch of magazines with road-test from back then )
nor have I've ever heard of it in all the discussions I've participated in, and read, at the CBX forum.
...and BTW, it has never happened to my CBX

Local clowns on old ratty Kawasakis and Yamahas would beat new CBXs in the street drags.

Sorry, but I seriously doubt that, (*)  unless said CBX had been in the hands of some ham-fisted 'mechanic'
which of cause is a possibility, cause as I said, back then very few motorcycle-'mechanics'
were qualified to work on this gloriously sophisticated machine.
Doesn't make it a bad design,
just makes it a design ahead of it's time  ( ....and ahead of the 'mechanics' of the time )


(*)
Bike magazine December 1978:
"..top speed: 135.13 mph , Standing 1/4 mile: 11.93 sec.."

SuperBike magazine Ocober 1978 . " This is it. The big one. Honda CBX, six cylinders of warp drive ":
"..maximum speed: 138 mph. Standing Quarter mile: 11.7 sec at 117mph..."

Finally Honda got smart and made a tourer out of it..

Wasn't really that smart. They were virtually unsellable.
In the end Honda gave them away for free to Tech. schools.
Ever once in a while such bike with zero miles on the meter
turns up, even now.
The CBX crowd refere to them as 'school bikes'.
You do NOT want the one's that have been through the hands of students
with more enthusiasm than actual qualifications. Stories of chewing-gum paper
and such inside these engines are rutinely reported.

 

Then the got even more intelligent and quit making them.  Ah yes, the memories.

Yeah, the were a short-lived "let's-show-the-world-how-to-make-the-fastest-bike" exercise.
A kick in the but to the mediocre...

'Bad design'...NO way.
I've worked on it, and I can come up with a rather long nice list of
features on this bike that are just totally brilliant.
Have a ride on a well and properly set up CBX1000 Supersport
and you'd realize ( and this is what really counts at the end of the day) what an absolute HOOT it is.
It's fast as hell and completely rideable in a Ferrari-sort-of-way,
you can put it on top gear at 30mph and just woooooooooooooooooooooooooosssssssssh up to 125mph
like a flippin' freight train.

OK. Rant over.

Please enjoy these pictures of my 'badly design'ed CBX

During rebuild



Yep:  

There are enough parts in each one for two normal motorcycles

....or more,
( this is the carbs partly dismantled)


..but the result is glorious:










BTW: the sound isn't too bad either: ( Click image and turn UP sound )

 
  

[jimmy six]

I still want one. Tried to buy the one Mark Dees  had from his estate but didn't bid high enough.

[wobblywalrus]

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

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. 

[dw230]

"...I liked was the sound, didn't think they were very fast."

Only you could make that statement Rick.

DW

[fredvance]

We had a turbo CBX that used to run at the Texas mile. It ran in the neighborhood of 200.

[McRat]

IIRC, the CBX wasn't the only 6-cyl at the time.  Laverda?  Benelli?  Uh, some spaghetti rocket also sported 6 cyl and was even more $$$$ than the CBX.

[salt27]

I was told the vega block cooled off to quick and the the matereal did not set up properly. Same matereal in the Porsche 928 block but the Porsche kept the cylindrers warm and cooled then off at a controled rate. I don't know if that is true or not. But I had a 73 Vega that smoked something wicked.I have seen 928 engines with 250000 miles and no real cylinder ware.

I put over 200k on a 71 Vega.
It was the ultimate oil recycler.
I would put the used oil from my other vehicles in it [properly strained thru a sock of course].

Don

[johnneilson]

IIRC, the CBX wasn't the only 6-cyl at the time.  Laverda?  Benelli?  Uh, some spaghetti rocket also sported 6 cyl and was even more $$$$ than the CBX.

Didn't Honda build a thimble drone 125cc 6 cylinder bike for racing?

John

[McRat]

IIRC, the CBX wasn't the only 6-cyl at the time.  Laverda?  Benelli?  Uh, some spaghetti rocket also sported 6 cyl and was even more $$$$ than the CBX.

Didn't Honda build a thimble drone 125cc 6 cylinder bike for racing?

John

Not sure, but Honda did win the Science Fair Project Award with their NR500.  This was a 4-stroke grand prix bike that had oval pistons and 8 valves per cylinder. 

All the winning bikes were 2-strokes at the time, but Honda wanted to win with a 4-stroke.  They wanted 8 cylinders, but the rules limited it to 4 cylinders, so they just made the pistons oval.  It was a tech marvel, but could not win, and they went to 2-stroke later and followed the herd.