expansion chambers

[patak]

Hello all, i am fitting a set of jemco chambers to my gt250. What i am wondering is what sort of gap should i leave in between the two chambers, this is at the point under the motor at the chambers widest (thickest, fattest) point. Do expansion chambers expand under heat or vibrations?. At the moment in my rough mock up of the pipes i have about 15mm should i allow for a bigger gap. Here is a couple of pics.

Cheers

 

[teazer]

That's more than enough. 1-2mm gap is fine so they don't rattle against each other.

If you pull them in further than they want to go, the outlets will not be in the right place and will interfere with the swingarm. Yours look about right.

Those pipes look like Swarbricks with tapered headers and stingers not welded in.

 

[patak]

Thanks for the info, yeah they came in 3 parts, headers, chambers, stingers. Just wish i could weld.....

 

[teazer]

If the headers are not welded on yet, try rotating the body of the pipe to get the rear (baffle) cone pointing the best way for the tailpipe (stinger).

Back in the day, I used to rent a stick welder to tack parts together and took them to a local welder. Then I bought an Oxy set and my welding still sucks, but I can tack things together. If not I use aluminium duct tape and scribe or mark lines to show the alignment. Use a Texta (Oz) or Sharpie (US).