REFLECTOR: Duct ventillation

[Jerry Teitsma]

I have also experienced very hot temps in the ducts both on the side 
carrying the oil lines and on the other side.  I stopped or reduced this 
temporarily by stuffing the duct opening at the firewall.  I have reasoned 
that I am building up too much pressure under the cowling.   I have a 
Franklin engine in a standard size velocity and the exit area at the prop is 
quite congested.  I am attempting to solve the perceived pressure build-up 
by building a reverse scoop on the bottom of the cowling to pull air out of 
the engine compartment.  This should also aid in cylinder head cooling.  I 
have not yet flown with the modification so time will tell.

Jerry Teitsma
Velocity 173 FG
Granby, CO
N241JT