> the lower firewall extends forward much further than the
>stainless steel version, reducing the exit area for cooling air through
>the cowl, particularly in a monowheel XS. This might not be a problem
>in some Europas, but ours had excessive temperatures in the lower cowl.
>In the process of trying to improve the airflow through this area, we
>eventually removed the lower section of the phenolic firewall, replacing
>it with something similar to the factory design. It is possible that
>the baffling arrangement that eventually solved our problem would have
>been effective even with the full phenolic firewall in place, but it was
>too late to try this combination at that point.
>
>Dave DeFord
>N135TD
Dave,
The critical factor is the ratio of the inlet area to that of the outlet
area from the cowling, which is not really affected by the firewall itself.
If too much air is trying to get in it can effectively block the inlet. Jim
Nelson reduced his inlet area and AFAIK improved his cooling. I suspect he
reduced it before he actually flew but he seems to have had a pretty good
idea of what he was doing. He may respond to this?
Jim's is an XS BTW.
Graham
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