Has anyone else noticed the header pipes on the 2014 standard, equipped with a four-into-one collector system, are intentionally designed to have uneven lengths?
With a standard crank design of an inline four, a cylinder fires every 180 deg of crank rotation. The most efficient exhaust scavenging would result from headers that were equal length. The pipe for the #1 cylinder, which has the longest run to the collector on the far side of the bike is intentionally made even longer than it needs to be, with an out-of-path bend. #2 has been made longer as well.
In an equal length setup, the #3 & 4 would be bent to add a little length so as to match #1 & 2.
Any thoughts?
Helmholtz resonator
Sorry, that's all I know about exhaust theory
I trust the engineers at Honda explicitly. I can’t imagine that they didn’t consider what the impact on performance and reliability the pipe lengths would have on their design. Based on that I’m guessing the impacts were negligible.
If there was a noticeable issue, it would have failed at Design Verification. Maybe it did, but they addressed the issue in one or more best know methods (e.g. popgun's resonator remark).
Perhaps for oil filter access?
With 0-60 in 3.3 seconds, I would not be concerned.
That's probably the reason, as engine output wasn't the chief goal with the 1100. In any event, the 4 into 1 set is vastly superior in exhaust scavenging compared to the 4 into 2 with a crossover pipe of the other CB1100 models.
HP was not the prime objective, but overall performance is very pleasing.
Just before I replaced stock tires at 10,579 miles, I did a few hole shots. Above 4,000 RPM, full throttle, the rear broke loose and went a bit sideways...more than once...and the stock Dunlop was not slick...quite a bit of tread left. Hitting over 60 MPH in first gear in 3.3 seconds may not match a crotch rocket, but still a thrill.
86 HP @ 7500 RPM
65.6 ft lbs @ 5700 RPM
0-30 1.2 seconds
0-60 3.3 seconds
0-90 6.8 seconds
0-100 8.6 seconds
1/4 mile 12.11 seconds @ 109.25 MPH
Hi Doc, we've missed you. Hope you're doing well.
it can be a desing-construction thing (examp. access to the oil filter)
but
an exhaust is a highly complex matter ( not just in terms of sound)!
different gas pressures or flow velocities resulting from different pipe lengths and shapes....and bringing them together in the right place , like 4into1
or why is the 4in1 considered sportier sometimes (power) ? why for what we have sometimes a "interference tube" at the exhaust, my honda VTX 1300 had it ?
well i cant find a english site...but with the online translater
https://www.motorradonline.de/zubehoer/a...lles-rohr/
and I quickly found no scientific page on gas flows (speeds/pressures) in (exhaust) pipes.....