Hi all,
What is everyone's thoughts on unbalanced and balanced exhaust pipes on the A65?
I would like to know if there is any real benefit in having the balanced system, especially as I am fitting a large valve ported cylinder head, along with a 750 kit and 32mm carbs.
Aesthetically I like the look of the balanced pipe set up but I have had problems in the past with a pair of balanced pipes that would just not line up properly. With the exhaust pipes correctly fitted to the cylinder head and the frame mounting point the stubs for the balance pipe were way too far out of line for the balance pipe to fit. After a lot of messing about getting my money back at the time I ended up going with the unbalanced type.
What do you think?
In my last profession I made stainless exhaust systems for cars, what I have learned is that the way the factory did their balance pipe is a complete waste of space.
If you compare the balance system on any modern bike the balance is of X shape and is much closer to the silencers rather than being at the head in BSA fashion . Some other designs are of just a cross over pipe or a box but again its much much closer to the silencer.
Hi Allan,
Are you saying that the A65 balanced system has no benefit at all and there is no advantage over the non balanced, other than any aesthetic appeal it may have?
Cheers,
Kev
The silencer results in a certain back pressure which impairs the emptying of exhaust gas from the cylinder. With a balance pipe the cylinder empties into two silencers so from a back pressure point of view the balance pipe should be beneficial. Cheers
Hi,
I would think that the balance pipe that is used would not be as effective as a 2 into 1 into 2 or a simple 2 in to 1. The need for the gases to turn through 90 degrees twice would not be as affective if having any effect at all. If fluids act in a similar way then the exhaust gasses will rush past the balance pipe and either not use the balance pipe as an extra exit or will actually suck the gases through. Imagine water in a fast flowing river - back waters are created by the faster flow with little or no mixing of the water whereas two parallel streams will vary the draw on any connecting ditch depending on the speed of flow in either stream. The x configuration suggested by Allan would provide the increased silencer volume whilst providing interference with the reverse pulse. Two into one seems to have the advantage of reverse pulse interference but the disadvantage of one silencer. Perhaps the silencer on a 2 in to 1 needs to have a big volume and a large outlet so possibly having negligible affect on the back pressure or reverse pulse.
Dave.
Dave.
I agree with Dave on the points above but as the exhausts are a push fit into the head, they need something to brace them to hold them there. The A50 didn't have the balance pipe but had a flat strip bolted to small bosses on the underside of each pipe at the outlets.
My A50 has the balance pipe only because I bought the downpipes second hand from a member who had an A65 and was fitting brand new pipes. However, I would have preferred the standard A50 although they look a bit naff but are dead easy to fit and seal well.
Hi,
Just checked the outlet on my 'Goldie' type A65 silencer and it has a cross section of just about 3 squ. ins.
A normal type silencer is about 1.76 squ. ins. Not quite twice the size but significantly bigger. I will try to work out the volume of the whole silencer if I get bored.
Dave.