Blast tube question.

[rv9aviator]

I have a cooling shroud around the fuel pump on my Lycoming 0-320 and would like to add a hose to help cool it. It takes a 2 inch scat hose. My question is: doesn't every hole you cut in the back wall of the baffling just lose that much more cooling to the cylinders. I already have a 2 inch scat hose going to the cabin heat on one side and the oil cooler is on the other side. I'm concerned about causing heating problems by adding another 2 inch scat hose. Thanks!

[kentb]

2" is a lot of air for a fuel pump.
I have a 1 inch and no shroud and it work great.

Kent

[rv9aviator]

I thought that too. The factory Piper shroud that came with the engine is what I have on it. I could always adapt it down to a 1 inch. I wonder why they went so big?