Design Disadvantages of the CB1100

[Deanohh_imp]

I keep hearing that legend but I don't believe it. A more believable reason for the different valve timing of #2 & 3 is the theory that it helps the cooling of the center 2.

[Pauley]

http://www.ridermagazine.com/road-tests/...-test.htm/

About the 7th paragraph describes the "Intentionally staggered intake-valve timing gives it a slightly rougher feel reminiscent of the earlier fours". Not terribly technical but that's the gist of it. Doesn't sound like Quality shortcut.


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[calamarichris_imp]

"Intentionally staggered intake-valve timing gives it a slightly rougher feel reminiscent of the earlier fours,"...
Jesus' trousers. It's right there.
An intentionally retarded engine. Color me blue, that was a dumb thing for Honda to do. If I wanted less efficiency, I'd buy a Harley and pretend to be an outlaw.
They could have omitted a spark plug for those who want the reminiscence of earlier fours, so that those of us who want smoothness/efficiency/long service life could remedy it by paying extra for a custom spark plug.
I wonder what kind of mileage, or what kind of power these bikes would make if they weren't hobbled by such engineering/marketing.

Any chance this is just some journalist taking a little too much poetic license?
Honda completely screwed the pooch with the VTR1000 Superhawk IMO, but this is almost as bad.
Rougher feel = less smoothness = shorter and less efficient lifespan.
Damn. I haven't been this crestfallen since BMW-USA's reaction to the surging issue.

There really is no perfect design.

[Deanohh_imp]

I believe everything said or written by all journalists, marketing hypesters, politicians, and bloggers.

[Rolls_imp]

I share Deanohh's skepticism of this possible urban legend.

Bristol Post article states valve timing was altered for sonic attributes:

A nice touch by the Honda engineers is that the valve timing on cylinders one and four has been timed slightly later than cylinders two and three to give a warbling exhaust note reminiscent of a bygone period.



Read more: http://www.bristolpost.co.uk/CB1100-EX-f...z2szrZz7CI

[Guth_imp]

Everything designed by the hand of man has its advantages and disadvantages. As PeeWee Herman says, "Everyone I know in life has a big but(t)...":
~Harleys sound great and you never have to adjust the valves, BUT they're slow, inefficient, and the rear cylinder does not get as much cooling air as the front. (That, and you have to ride everywhere with a serious scowl of determination on your face, as if you are on your way to commit your third-strike felony.)
~Crotch-rockets are light & fast, but the cylinders are bored into the top half of the crankcase (disposabike) and being stuck behind an RV on a twisty road sucks even worse when you're on one of them.
~Vertical Twins (one piston goes up while the other goes down) can rev higher and are generally more efficient overall, but they get lumpy and weak at low rpm.
~Parallel twins (both pistons rise & fall together) are terrific at lower rpm and have a sweet, balanced sound, but they create a pressure maelstrom in the crankcase which inhibits higher rpm power.

So what are some of the advantages and disadvantages of the CB11's engine? Not interested in the smile-on-your-face while riding on a sunny day advantages. Every design has its disadvantages, what are the CB11's?
Heavy weight?
Plastic bits?
Throttle governor?
Less cooling air for #2 & 3 cylinders? (Are they jetted identically with #1 & 4, or richer/cooler?)

Of course, the advantages of and disadvantages of those things designed by the hand of man pale in comparison to the advantages and disadvantages of man himself. In this case, I'd ask what exactly is it that you're looking for from this engine? Only by answering this question can you begin to address advantages and disadvantages when it comes to the CB1100. (i.e. If your not inclined to ride over 110 mph, then the speed-limiter isn't a disadvantage.)

How many Harley owners are concerned about riding overly fast or how much cooling their rear cylinder is getting compared to the front? Chances are it's a very small percentage. Conversely, what percentage of supersport class bike owners are concerned with how sedately their bike cruises when not being pushed or even have thoughts of long-term ownership? How many guys with twins are really worried about the lack of low-end or high-end power of their respective machines? For most, these disadvantages from a purely technical sense aren't disadvantages at all. Those who consider such items as disadvantages are more than likely those who didn't properly consider their own needs.

In my mind, you have to have something to measure against (in this case the desired use for the bike) to try and identify the respective disadvantages. My needs are bound to be different from yours and therefore what I see as an advantage or disadvantage might vary quite a bit from you, especially if your not concerned about the "smile-on-your-face while riding on a sunny day" type of stuff. It's honestly hard for me give you much feedback as one of my actual requirements was for a bike that I got as much enjoyment from looking at it when I was off of the bike as I did from actually riding it. What can I say, I went to school for engineering and ended up working for a number of years as a graphic designer, I'm a bit skewed.

I quickly identified two issues with the bike that were a disappointment to me. Thus far these are my only real gripes:

1.) The weight of the bike when moving it around in the garage and so forth. Obviously this can't be chalked up just to the engine, but the size of the engine surely plays a part in this. I'll simply live with this and won't be addressing it further. Once the bike starts rolling, however slowly, I'm good with it.

2.) The tone of the factory exhaust. Simply too peaceful for me. I'm not a fan of loud exhausts, but I do like an exhaust note with a bit of soul if you will. I addressed this by adding a slip-on exhaust from Staintune and I've been very pleased with the result.

Some issues, such as engine longevity, will only be answered in time. People can theorize as much as they want, but until enough units have withstood the test of time and miles (or not), theories will remain just that.

At this point, I can't tell you much at this point about working on the bike. That will change over time as I plan on doing pretty much everything on my own. I'm no expert mechanic by any means, but I've learned a heck of a lot by doing all of my own work on my Hawk GT (the only other street bike I've ever owned) over the past 7 years, and I like the feeling of satisfaction that I've received from that experience. No reason to change things up at this point. If I fail at something, then I can pay somebody else, but until that time comes, I'll keep turning my own wrenches.

With all that said, as mentioned, my Hawk GT is the only other street bike I've ever owned. A 647cc V-Twin and an 1140cc Inline Four don't exactly make for a wealth of experience. Therefore, for better or worse, my expectations are probably far different than many guys here who have owned a wealth of bikes over the years and have a lot more comparables to draw from.

[kevbroce_imp]

http://world.honda.com/design/designers-talk/cb1100/
http://world.honda.com/CB1100/engine/index.html
I would think if Honda altered the engine timing it would be mentioned in there, and does that sound like anything Honda would do?

In fact, "Smooth, instantly accessible power and torque is what the CB1100's motor's all about, and plenty of it, anywhere in the rev range."

Either way, your might be thinking hard about this, just go ride the thing.

[Guth_imp]

From the Factory Service manual...

Intake timing for cylinders 1 and 2:
opens at 5 degrees ATDC, closes 28 degrees ABDC

Intake timing for cylinders 3 and 4:
opens at 5 degrees ATDC, closes 38 degrees ABDC

Exhaust timing for cylinders 1,2,3 and 4:
opens 42 degrees BBDC, closes 10 degrees BTDC

Maybe this is done to broaden the powerband of the engine as opposed to doing so for nostalgic reasons? At any rate, I'll take my chances, choosing to side with Honda's engineering team.

[enzo_imp]

WOW.....I just got what I payed for. And if I had the money to bye any other bike I wanted I would regardless of mark.
But there is so many bikes that have gone before, La Verda, Vincent's, Some beautiful Triumphs, Nortons,
I'm not a thrasher of bikes but the CB 1100 is a gentleman's motorcycle not a rev head's. There plenty of bikes out there to choose from for whatever need. I you have a CB 1100 and don't think is up to your standard it's not the bikes fault you have chosen the wrong bike for your need or use.

[Deanohh_imp]

From the Factory Service manual...

Intake timing for cylinders 1 and 2:
opens at 5 degrees ATDC, closes 28 degrees ABDC

Intake timing for cylinders 3 and 4:
opens at 5 degrees ATDC, closes 38 degrees ABDC

Exhaust timing for cylinders 1,2,3 and 4:
opens 42 degrees BBDC, closes 10 degrees BTDC

Maybe this is done to broaden the powerband of the engine as opposed to doing so for nostalgic reasons? At any rate, I'll take my chances, choosing to side with Honda's engineering team.

From a previous post:
this is a misprint in the shop manual, happens all the time with a non procedure specs.if this was a service check procedure red flags would have flown very early from feedback from service engineering and field service techs.i'm sure it will be corrected by next shop manual printing if Honda knows about it.
correct spec should read-
intake timing for cyl #1 and#4 opens at 5 degrees atdc, closes 28 degrees abdc
intake timing for cylinders #2 and #3 opens 5 degrees atdc, closed 38 degrees abdc
Paul. Sr.Tech. Specialist, American Honda Motor Co.Inc= Retired.