----- Original Message -----
Sent: Thursday, December 24, 2009 3:23
PM
Subject: [FlyRotary] Re: Meredith Effect
- Spitfire
I'm wondering if that figure for airflow is true (2x airflow
for water cooled vs air cooled). All the measurements I have seen
(not many) indicate that the exit air temperature on a Lyc installation is not
significantly different than on our water cooled engines. The total
heat per HP is not that different so my assumption is that the CFM requirement
is not much different.
The only advantage the air cooled
engine's higher Dt gives you is that it requires far fewer square inches of
surface area to transfer a given number of BTU with a given number of
CFM. Our advantage is that we can add surface area a LOT more
easily than an air cooled can. You can only put so many fins on a
cylinder head.
But I may be missing something. Other
thoughts?
Tracy