Aluminum expansion chambers?

I feel the need to ask a question, why are expansion chambers made of steel? Why not aluminum, it would be quieter and lighter.
I remember seeing the works MZ’s with alloy tank, seats and faring but I cannot remember if the exhaust were steel.

Hello,

MZ chambers have always been from steel.
I am no specialist but I think that Aluminium would not vibrate the same way.
Sorry for my poor wording (vibrating is probably not the good word).

Probably you will get more details by the real specialists of 2 stroke tuning here.
Fred

Hi

My take on this is very high quality aluminium has to be taken up to over 800 degrees, to melt and solidifys around 725 to 745 degress

low grade meelts much earlier 650 degrees.

Temp in an exhaust is much higher than this, add to this the sonic pulses

aluminium would not last 5 minutes unless very thick? even then it would work harden very quickly and fail.

as its very prone to cracking on the part of a bike that generates all the cracking forces from vibration.


regards Derek

Thanks Derek and Fred fpr your replys.
That was all I wanted to know, once an explanation has been given I can move on.

no worries colin what about some photo;s hows the bike comming on

i will let you know once we have a meeting place some wear south m42 to make it accessable for the guys in cheltenham.

i deally bring your engine bits pieces we can discuss assemble.

on the meeting i will post everyone, once i have confirmation on location, if you have dates you can not make, its agreed we shoul meet on a sunday afternoon/ early evening.

regards Derek

Hi Derek.
I’m ok with the meeting, something to look forward too.
I don’t really have any thing to photograph yet I have done some mods to the frame, with more to come. I am taking tyres, hubs, and rims over to Birmingham this week (picked up my race tyres last Friday) I have to reseal forks and caliper, then I can start to rebuild the frame.
I don’t want to start the engine rebuild until I have the gearbox mods complete, I know I will not be fast but if I sort the gearbox and clutch first that is less problems to over come later. I still hope to have the bike running by Christmas / New Year.
License form ready to go off, just have to book onto a track awareness day, and off we go.
Colin