Will Heat shrunk plastic cowls melt from the heat of the engine?

[jwood]

Will Heat shrunk plastic cowls melt from the heat of the motor?

I have read articles about molding a plastic soda bottle over a mold of an engine cowl using a heat gun.
Or getting plastic sheets, and using heat and a vacum box to form a plastic engine cowl.
But the engine itself gives off heat. If the plastic shrinks to form around a mold, wouldn't it also slightly warp from the engine heat, once it has been installed on the plane?
I was just wondering if anyone had heard of this happening.

Thanks
Jeff Wood

[Dave Robelen]

Hi Jeff,
The reason the plastic survives the engine heat is air circulating thru the cowl. If the cowl were closed off in the back completely, two things would happen. First, the part of the cowl nearest the cylinder head would begin to deform from the stored heat, and second the engine would rapidly overheat. Regardless of the cowl material, there must be an adequate exit for the heated air for the engine to run properly.
Regards, Dave Robelen