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Dear Dennis
Could you contact me off line about your oil cooling problem.
Thanks
Regards
Ed Klepeis
tech welding.com
----- Original Message -----
Sent: Saturday, September 22, 2007 10:40
PM
Subject: [FlyRotary] RV-7A Cooling
I still working to improve my oil cooling -
Renesis engine, PSRU 2.8:1, Catto 76X88 composite prop, water and oil
radiators under engine at about 30 degrees to inlet air flow, James cowl -
shark intake under spinner . See pictures below.
Today I
flew and recorded some temperature and static pressure numbers for anyone to
comment on.
Test conditions:
90 deg OAT = inlet air
temperature
About 6500 foot altitude
TAS - GPS and EM-2 : 165 mph
Manifold pressure 20in.
RPM 5700
Water Temp - 192 deg F
Oil
temp leaving oil cooler - 207 deg. F
Oil temp in oil pan - 235 deg. F
Temp of heated air leaving oil cooler -135 deg F (135-90 = 45 deg temp
rise of cooling air through the oil cooler)
Temp of heated air in cowl low
and near firewall 133 deg. F
I measured static air pressures at
5 points inside the cowl as follows:
1). Inlet side of oil cooler:
10.5 in water
2). Back side of oil cooler: 4 in water ( 10.5 -
4 = 6.5 in water pressure drop across oil cooler.)
3). Midway between oil
cooler and firewall: 2.75 in water
4). Right side within 4 inches of
firewall and 3 inches above bottom of firewall: 2 in water
5). Left side
within 4 inches of firewall and 3 inches above bottom of firewall: 2 in water
Before these tests Bobby H. and I were thinking I needed more
outlet area to improve my cooling. I am seriously considering
a big
cowl flap to lower the pressure in the cowl. Does this data support this
position?
Hopefully better minds than mine will know!!
Dennis H.
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