+- The CB1100 Community Forum (https://cb1100forum.net/forum)
+-- Forum: Honda CB1100 Discussions (https://cb1100forum.net/forum/forumdisplay.php?fid=5)
+--- Forum: General Discussion (https://cb1100forum.net/forum/forumdisplay.php?fid=6)
+--- Thread: valve timing inaccuracy? (/showthread.php?tid=3292)
valve timing inaccuracy? - VTR1000F_imp - 11-24-2014
There´s a talk about valve timing defect "built-in" to our engines to create a "character" of old inline four. How would the CB feel with straight timing? Big enough difference to feel it? Where is this achieved, mechanical wise? Camshaft lobes? This is just something what popped up in my head on lazy Friday :-)
RE: valve timing inaccuracy? - CA200_imp - 11-24-2014
VTR the manual shows intake values different on the intake cam, 28 degrees on #1 & #2 and 38 degrees on #3 & 4# ABCD
RE: valve timing inaccuracy? - VTR1000F_imp - 11-24-2014
so..who will be the first to make custom "straight" camshaft? :-)
RE: valve timing inaccuracy? - gossman_imp - 11-24-2014
Certainly wouldn't refer to it as a defect since it was purposely designed that way, much like the Harley lope. I'm not unhappy with it, I like the way it's designed. Want more hp? Buy a cheaper CBR1000.
RE: valve timing inaccuracy? - AndyHe_imp - 11-24-2014
With a straight camshaft, wouldn't you also have to reprogram the firmware? I know very little about this area but I'd assume reprogramming would be required. And would this make progress toward eliminating the vibrations many feel around the 3500 RPM mark? Or would it only add a bit more power?
RE: valve timing inaccuracy? - rocket_imp - 11-24-2014
I think VTR1000F should explain exactly what " straight timing " means before we go any further. Yes, valve timing can be altered for different power delivery characteristics, but what are you looking for ? Maybe you have the wrong bike. Many posts on this Forum have discussed the smooth, even power band as being one of the attributes of the CB1100. If maximum power is your objective, buy another bike.
RE: valve timing inaccuracy? - the Ferret - 11-24-2014
Rocket I think he is just wondering what the CB 1100 would be like if Honda had not set the valve timing to produce the feeling it does at certain rpms.
I don't personally think it would feel much different.
RE: valve timing inaccuracy? - VTR1000F_imp - 11-25-2014
(11-24-2014, 10:42 AM)rocket_imp Wrote: I think VTR1000F should explain exactly what " straight timing " means before we go any further. Yes, valve timing can be altered for different power delivery characteristics, but what are you looking for ? Maybe you have the wrong bike. Many posts on this Forum have discussed the smooth, even power band as being one of the attributes of the CB1100. If maximum power is your objective, buy another bike.
Don´t get me wrong. As Ferret says, engineers at Honda implemented offset to valve timing to reproduce a "retro" feeling and buzz to our inline four. They said, without that imperfection the engine would feel "too perfect". I´m absolutely happy with my CB performance, but I was just wondering about this matter and for the sake of discussion.
RE: valve timing inaccuracy? - AndyHe_imp - 11-25-2014
I'm also wondering what a "too perfect" engine would feel like. Sounds kind of nice to me.
RE: valve timing inaccuracy? - nhawk7504_imp - 11-25-2014
All the valves even instead of offset like that WOULD be nice. We can say all we want about engineering in the past. But this is 2014. The question is not horsepower. The engineer CHOSE to make an engine that ran a little rough timing wise. Then we need grips and bar ends and six speed transmissions to try to "fix" it. My Dad was an aeronautical engineer. They did not engineer vibration into planes. When I test rode the bike, the vibes came thru the seat. I would not choose to engineer in vibration. That's just me. Vibration is not a good thing from an engineering perspective, and in some ways, from a health perspective either. See: http://www.ccohs.ca/oshanswers/phys_agents/vibration/vibration_effects.html