Under engine Balance pipe

I think the advantage in a 2 into one into 2 might be that you could get the noise levels lower with two parallel high flow mufflers. My 2 into one is extremely loud. The lack of back pressure after the first collector is important. With a 2 into one pipe, you will find that if the outlet dia. of the collector is too small it can cut a lot off the top of the usable rev range. I don't use Maney type large dia. header pipes, I think that way the system is more energetic.

Very commendable effort Ludwig, and was there a difference with the valve opened and closed ? Perhaps you could have wired it up to the engine management system and patented it ? Sort of like the exhaust port height adjustment on a Yamaha two stroke ?

Ludwig, I for one, would like to know the results of your balance tube experiment as I've been trying to decide if it was worthwhile to incorporate one in a homemade exhaust I've yet to build. I've also been wondering if an under engine balance would yield the same results as the close to head tube, any thoughts appreciated...Mark

I've never believed the balance tube used on 650cc Triumphs ever did anything except take the edge off the motor. They first appeared on the Saint 650 which had the light crankshaft, you would not want that bike. The good thing about the balance pipe was that it stabilised the mounting of the pipes- less risk of shagging the cylinder head.There was a time when BSA and Triumph were trying to build motor scooters which looked like motorcycles. However the 1963 Bonneville was a beautiful bike.

I know my swept back Dunstalls had the balance pipe (flexible type) up close to the head but never experimented, just assumed that Mr. Dunstall knew more than me. It would be nice to know how Ludwigs experiment came out but just reading between the lines I'm inclined to believe he saw no difference. Although, even if it's only saving grace was a quiter exhaust, then I'm all for that but I'd still like to run the balance beneath the engine, not enough air going by that head as it is.

Yes the '63 Bonnie was a nice looker but than so is my '66, light crank and all, although it will be getting a later heavy crank once reincarnated...Mark

Please do an under frame cross over experiment. The way to optimalize the cross over tap points is run a paint stripe along area of interest and run up to desired rpm for best effect then shut off and see where the heat concentrated the most. No extra benefit gained in X-over tube bigger than ~1/3 the main tubes. This is not related to pulse extraction Y joints. Crossing close to head is for practical convenience only to get main benefit but not optimized. X-over are not a dramatic improvement but pleasantly noticeable in sound and spunk.

I was always surprised that the lighter crank in the Triumph Saint 650 was a backwards step. To my mind it should be better. However I was totally wrong about the heavy crank in the commando engine - I love it, especially with the close box. Ludwig didn't say much about his crossover with the valve, however it seems like a smart thing to do. My feeling is that any pipe connected to the exhaust at right angles must resonate at the frequency determined by it's length. I find it hard to imagine how the combinations of the header pipes and the crossover can work effectively in theory. With all these things, unless you try it you never find out. With the two into one, I believe the tail pipe resonates at twice the frequency of one header pipe. I was surprised how much a restrictive outlet from the collector can kill performance.

Just to show how serious some manufactures took this show is a collector box as fitted to the CX 500 range ( also cx650) it has U pipes inside transferring exhaust gases to the other exhaust silencer .

http://www.bing.com/images/search?q=hon ... tedIndex=1