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1. 07:38 AM - Re: High oil and fuel pressure (Thomas Law)
2. 07:58 AM - Re: High oil and fuel pressure (Thomas Law)
Message 1
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| Subject: | Re: High oil and fuel pressure |
--> RV6-List message posted by: "Thomas Law" <tlaw@klondiker.com>
John, I think you may have a poor ground between the instruments and the transducers.
They are affected by very very small voltage chages in the ground path.
One quick check you can do for the panel ground .......turn on all the electrics
one at a time (engine off), inc. radios (recieve and transmit) , panel
lights, power points, etc, and make sure the gauges stay at "0". There may be
some very slight movement as the system voltage will be changing.
Tom Law RV6A, Whitehorse, Yukon
---------- Original Message ----------------------------------
From: "John Brunke" <jwbrunk@attglobal.net>
>--> RV6-List message posted by: "John Brunke" <jwbrunk@attglobal.net>
>
>Most of you folks are good at problem solving. I think I know the answer but
here's the situation.
>
>Flew my RV-6 with an O-320 last week. Air temperature was 6 degrees F. Oil temp
never made it above 150 degrees. As I leveled off and the
>fixed pitch prop rpm came up to normal cruise, the oil pressure came up to just
below or at red line and fluctuating about 2 to 3 psi. I reduced RPM to
>1700 and slowly came back in to land and the pressure stayed around 85 psi (red
line is 90). In the pattern when my airspeed was back below
>100 mph the oil pressure was in its normal range around 80psi.
>
>Ok, it was a really cold day. So I'm thinking that the oil cooler was getting
too much air flow. I was able to block 1/2 of the air flow and flew a couple
>of days later when it was in the high 30's. Flight went great.
>
>Went flying today and the air temp was 23 degrees. Even with half the airflow
to the cooler blocked the pressure fluctuation up near red line occurred again.
>
>This aircraft has Van's engine gauges and I was also venturing that the transducer
might be bad, but during these high oil pressure indications the fuel pressure
>would also rise. They would rise at the same points. I'm concerned because
redline for fuel pressure is 8 psi and the indication at one point was 12 psi.
>
>So, has anyone run into too much cooling for oil and if so did it also affect
your fuel pressure?
>
>Also, I am concerned about the fuel pressure excursion above red line. What specifically
do you think I should check? I took the cowl off after today's flight
>and did not notice any leaks.
>
>The engine was about 45 degrees F when I started it. It is kept in a heated hanger
so the oil was not at ambient temperature when I started it.
>
>I would appreciate your comments.
>
>John Brunke
>St. Charles, IL
>
>
Sent via the WebMail system at klondiker.com
Message 2
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| Subject: | Re: High oil and fuel pressure |
--> RV6-List message posted by: "Thomas Law" <tlaw@klondiker.com>
John, I think you may have a poor ground between the instruments and the transducers.
They are affected by very very small voltage chages in the ground path.
One quick check you can do for the panel ground .......turn on all the electrics
one at a time (engine off), inc. radios (recieve and transmit) , panel
lights, power points, etc, and make sure the gauges stay at "0". There may be
some very slight movement as the system voltage will be changing.
Tom Law RV6A, Whitehorse, Yukon
---------- Original Message ----------------------------------
From: "John Brunke" <jwbrunk@attglobal.net>
>--> RV6-List message posted by: "John Brunke" <jwbrunk@attglobal.net>
>
>Most of you folks are good at problem solving. I think I know the answer but
here's the situation.
>
>Flew my RV-6 with an O-320 last week. Air temperature was 6 degrees F. Oil temp
never made it above 150 degrees. As I leveled off and the
>fixed pitch prop rpm came up to normal cruise, the oil pressure came up to just
below or at red line and fluctuating about 2 to 3 psi. I reduced RPM to
>1700 and slowly came back in to land and the pressure stayed around 85 psi (red
line is 90). In the pattern when my airspeed was back below
>100 mph the oil pressure was in its normal range around 80psi.
>
>Ok, it was a really cold day. So I'm thinking that the oil cooler was getting
too much air flow. I was able to block 1/2 of the air flow and flew a couple
>of days later when it was in the high 30's. Flight went great.
>
>Went flying today and the air temp was 23 degrees. Even with half the airflow
to the cooler blocked the pressure fluctuation up near red line occurred again.
>
>This aircraft has Van's engine gauges and I was also venturing that the transducer
might be bad, but during these high oil pressure indications the fuel pressure
>would also rise. They would rise at the same points. I'm concerned because
redline for fuel pressure is 8 psi and the indication at one point was 12 psi.
>
>So, has anyone run into too much cooling for oil and if so did it also affect
your fuel pressure?
>
>Also, I am concerned about the fuel pressure excursion above red line. What specifically
do you think I should check? I took the cowl off after today's flight
>and did not notice any leaks.
>
>The engine was about 45 degrees F when I started it. It is kept in a heated hanger
so the oil was not at ambient temperature when I started it.
>
>I would appreciate your comments.
>
>John Brunke
>St. Charles, IL
>
>
Sent via the WebMail system at klondiker.com
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