REFLECTOR: Clocking the Exhaust

[Velocity Aircraft Owners and Builders list]

I am removing my turbocharge because of cowl temperatures, and will 
install it at a later date after I've solved my other more pressing 
heating issues.  In a nutshell, I'm trying to reduce the complexity and 
address heating one variable at a time.  I am having hoses crack and 
sensors (crank timing for EFI) fail due to the heat.

I asked Clinton at Custom Aircraft about turning the exhaust straight 
back towards the prop, and he recommended against it, suggesting that if 
I do a merged log design, I'll need a ball joint and hanger to keep from 
cracking the exhaust where it turns down.

I've seen other examples where the exhaust is merged into a common log 
and points directly aft, using augmentation to help with cooling along 
the way.  How are people able to keep their props from getting scorched 
by the exhaust?