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Four Pipes or Not Four Pipes; that is the question?

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Laverda Dave:
Was that a Degans made exhaust Mick or did he sell them for somebody else?
My S&S Rickman Honda CR750 exhaust is a 4-1 and just like the Dresda system when I looked through the pipe called a 'silencer' I could see straight through it (just as I can with the Jota silencers). It was ear splittingly LOUD!

TrickyMicky:

--- Quote from: Laverda Dave on November 21, 2025, 11:29:58 AM ---Was that a Degans made exhaust Mick or did he sell them for somebody else?
My S&S Rickman Honda CR750 exhaust is a 4-1 and just like the Dresda system when I looked through the pipe called a 'silencer' I could see straight through it (just as I can with the Jota silencers). It was ear splittingly LOUD!

--- End quote ---
Bleedin' 'ell Dave, that was just over 50 years ago, and a lot of beer has passed since then!!  Couldn't tell you who made it, I was happy enough to be able to brag that "I've got a Dresda exhaust on mine".  I found it was a bit Jekyll & Hyde, whereby up to about 4000 ish RPM it growled quite acceptably, but once it got to breathing properly. Oh yes it was bloody loud.  Didn't worry too much, as by that time you were not hanging about, so it was mostly open road stuff. Have to admit though, that on the occasional Saturday night, 2nd gear got a few work outs round the Romford inner ring road, using the station bridge as the start line. Local plod only had blue and white Minors as panda cars. Sold it to get married, followed by my darling new wife saying that we really need another 750, the CD175 stop-gap being unacceptable. If the crappy photo uploads, it shows the result of a major spend:- New wife, new house, new matching Lewis Leathers kit, and a new 750, complete with No. 1 registration. GME 1N. (and 4 pipes !!).  John Collier's really was the window to watch in Romford for posing!!!

florence:
Surely the cylinders only go bang one at a time so three out of the four pipes are idle at any one moment  ;D

I have always had a 4-1 on my bike, less clutter, lighter, cheaper, lovely sound, what's not to like  ;D

Spitfire:
My K1 got a 4-1 system because it was supposed to increase performance, the 4 pipes were only refitted when I sold the bike.
However it also had something (a lot) to do with the sound, eventually a Dunstall 4-1 was fitted and it sounded glorious, my girlfriend had the kettle on way before I got to the house as she could hear the bike from miles away.

Cheers

Dennis

TrickyMicky:

--- Quote from: florence on November 21, 2025, 01:30:20 PM ---Surely the cylinders only go bang one at a time so three out of the four pipes are idle at any one moment  ;D

I have always had a 4-1 on my bike, less clutter, lighter, cheaper, lovely sound, what's not to like  ;D

--- End quote ---
I agree about the less clutter, lighter, comment.  The sounds of 4 pipes or 4 into 1 are both good, but definitely different. You pays your money, you takes your choice.  Some of the earlier 4 into 2 systems had numbers 1 & 2 siamesed, and 3 & 4 siamesed.  This meant that for each of those pairs you were actually putting a 2 into 1 system on a 180 degree firing arrangement, giving uneven breathing, and a not so smooth exhaust pulse/note. I remember there used to be a guy named Mick Hand who sprinted a C72 engined supercharged special, bloody quick as well.  I tried to sell him an old CB77 engine I had, but he told me that because of the uneven firing pulses of the 180 crank, the supercharging would not work. If you look at all the twins with that crank arrangement, you will see that they have twin carbs for the same reason. So, a 4 into 1 system must have 1 & 4 joined along with 2 & 3, or all 4 joining together at the same point for a smooth flow, and the correct back pressures.

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