Need a good heat shield material

[Ratfink]

Hi guys, I have a heat shield that runs between my header and the starter motor. currently the shield is a flat piece of .050 321 stainless about 8 by 10 inches . It works well for it's purpose, but keeps cracking. I have thought about bead rolling, or putting some breaks in the piece, so it can act like an accordion as it expands and contracts. I have also thought about trying a thinner, not so heavy piece, but I am un sure what would be best. Is there a better material for what I am doing?

[SShep71]

Try using 304l stainless and definitly take into consideration the expansion and contraction and implement it into your design. where is it cracking?

[exwestracer]

Give these folks a call: http://www.rcftechnologies.com/automotive/

Just saw this stuff at SEMA. We're doing some proprietary development work for them, and the material seems to be the real deal.