6" SS EXHAUST STACK

[David Brady]

Kurt,



I agree with Greg. I'm gonna keep mine stock. There's a bunch

of vibration and movement back there. I figure BB's been building

buses a whole lot longer than I have. Initially I'd scratch my

head when looking at the frame and support pieces, but when

you consider that something as big as a bus must twist and flex,

this flexibility needs to be designed in. Make one piece stronger

and you've created a stress raiser someplace else.



I have a friend who transplanted a honda v-tech motor into a

lotus elise. Everything worked but the alternator mount. The mount

insists on cracking. There can be some weird harmonics and

resonant frequencies going on that are difficult to grasp and

only trial and error and a 50 year track record of building buses

can solve (unless you can model it and run high powered

computer finite element analysis on it). He's still fighting that

mount...



Okay, I'm off my soap box.



David Brady

'02 LXi, NC



Gregory OConnor wrote:

Kurt, try and figure why there were 4 bends. it may be that it was


engineered to alow for swing room between the 'hung exhaust' and

the 'torque reaction of the ruber mounted detroit'. look at the roll

of the torque and see that there is a place for the movement to twist

a union. I kinda think this movement was the problem with the

resulting crack. crack=result ;movement=cause ;facilitate movement

=repair. may be that BB enginered it correct but someone

overtightened a band to cure an exhaust leak??????? you also got to

keep the stack from cantilivering off of the maniford with your new

design. Scavenging is one variable in fuel efficiency. even straight

pipes some time will result in lower fuel economy because the intake

variable get screwd. backpressure is mathed into the computer.

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