Took a test ride

[the Ferret]

I have read the staggered intake timing in multiple places, including interviews with the designer?

Listed on another forum

posted April 20, 2013 04:47 PM
unusual cam timing

A friend of mine just got a new Honda CB1100 and with it a service manual. He called me last night to ask if I had seen any motorcycle that had cam timing like the service manual listed for this new Honda. I had to say no and it left both of us scratching our heads.

First let me say I rode the bike and it is a nice piece. It is meant to be a bit of nostalgia with up to date handling and brakes. Back to the cam timing specs:

Intake timing for cyl 1 & 2 opens at 5 degrees ATDC, closes 28 degrees ABDC
Intake timing for cyl 3 & 4 opens at 5 degrees ATDC, closes 38 degrees ABDC
Exhaust timing for cyl 1,2,3,4 opens 42 degrees BBDC, closes 10 degrees BTDC

Different intake closing (10 degrees later & 10 degrees more duration) for 1,2 than 3,4
No cam timing overlap at TDC

I think the longer intake duration on 3 & 4 is to broaden the powerband

[vfrpaul98_imp]

no more comments from me, i promise.

[the Ferret]

Heck im no tech thats for sure..more like a parrot, repeating what ive heard over and over.lol

Just trying to understand.

Would cylinders 1 and 2 be inner cylinders?

[vfrpaul98_imp]

Intake timing for cyl 1 & 2 opens at 5 degrees ATDC, closes 28 degrees ABDC
Intake timing for cyl 3 & 4 opens at 5 degrees ATDC, closes 38 degrees ABDC
Exhaust timing for cyl 1,2,3,4 opens 42 degrees BBDC, closes 10 degrees BTDC
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.

[Lord Popgun]

Paul,

Thanks for the correction. I'm going to add that to my manual.

[the Ferret]

Paul,

Thanks for the correction. I'm going to add that to my manual.

+1. Thanks Paul.

[oldgoat01_imp]

Paul,

Thanks for the correction. I'm going to add that to my manual.

+1. Thanks Paul.

+1. Thanks Paul.
As will I (not really)...I mean I'm not even sure if those degrees are in Fahrenheit or Centigrade!

[Lord Popgun]

Paul,

Thanks for the correction. I'm going to add that to my manual.

+1. Thanks Paul.

+1. Thanks Paul.
As will I (not really)...I mean I'm not even sure if those degrees are in Fahrenheit or Centigrade!

+1. Thanks Paul.
As will I (not really)...I mean I'm not even sure if those degrees are in Fahrenheit or Centigrade!
It may be Kelvin, or Newton meters, or maybe furlongs

[bubblerboy64_imp]

Back to engine vibration. I've got some to compare so here is my opinion. It's subjective. Harley's (well some of them anyways) don't vibrate they SHAKE. If you mention that to their owners typically the response is something to the affect well "they smooth out once you get rolling". This is pretty much true but sitting at a stop light shaking would get old for me. The counter balanced engines much better.

BMW twins? If you twist the throttle at rest the bike actually jerks right and left but again smooth out at speed. There is some buzz from any two cylinder engine and certainly the singles are worse yet. The more cylinders the smoother on the average. How the engine is mounted makes a difference as well. Have had a couple Harley sportsters and the rubber mounting of their engines had made a HUDGE difference. A early sportster is absolutely crude compared to a new one.

The CB1100 and again in my opinion is over all a very smooth running and riding bike but I do notice a area in the rev band where there is some buzzy vibration. Those who don't notice it probably are coming off motorcycle that are worse and or are just taking this as normal for any motorcycle (which I think it is) If you keep the revs at or around 3000 RPM's there isn't much out there smoother. Depends a little on riding style.

BMW's. I like them but I've found them WAY too expensive to repair. Sold my last two. Honestly I like my Triumphs as well as the Honda's. And the Harley's have not been a lick of trouble either. Harley makes a nice machine they just seem to cost more and sell better then the other stuff. I feel it's image to a large extent. Having said that when you entire a Harley dealership you have to be impressed with the presentation. The bikes look fantastic in the show room and they look good on the road as well. Sex sells and Harley's are sexy boys.

[rboe]

My V twin GRiso is smoother at highway speeds even when she is running a higher rpm. I think it's because it has fewer firing pulses at that rpm than the Honda with twice as many spark plugs.

Down low the twin has some vibe to her but it's low frequency and "pleasant". You feel it as power vs. a vibration. The Honda is very electric at 3K and lower. But a buzz does come in around 4K. I need to spend more time at freeway speeds to explore this a bit more. So far, the limited times I've spent at around 70 have been OK. I just don't have the roll on acceleration the Griso has. But I bought the bike because it did NOT produce the power the Griso did in the theory I'll spend less time visiting with EMT's and nurses.