Mike .Andy Draper said originally the gills were there for heat escaping
on shut down. He did tests during flight and they were practically none
effective.
On shut down they are below the hot air collecting in the cowl top and
are not as effective as opening the service access doors. However
probably provide some escape route if parked into wind.
On the Jabiru the whole downward cooling principle made it necessary to
have all alternative outlets above the engine blanked and so keeping the
cowl top internal pressure high. My 914 has the barrel hood fitted also
demanding downward flowing air. I don't have Rotax cooling issues with
the small diverter flap in the lower cowl to boost prop wash into the
radiator when ground running. (The modified lower cowl radiator entrance
however could have been about 4" lower.
Regards
Bob H G-PTAG
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Mike Parkin
Sent: 01 April 2009 17:31
Subject: RE: Europa-List: 914 Waste gate servo mounting position
question
I do not have the "gills" open (left them closed since it has been
established that they were a development item providing little cooling
benefit on shut down(positioned too low) and are now a "leftover" item.)
Regards
Bob Harrison.G-PTAG
Bob,
That statement is just not correct. In flight, there is a noticeable
flow of hot air from the gills - obviously aiding the flow of cooling
air across the cylinders. Perhaps that is why you have had cooling
issues on Jabiru and Rotax.
Regards,
Mike
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