Interesting Takeoff This Morning

todehnal · #1 11-12-2016, 02:01 PM

It was a cool morning as we left on our 90 nm flight heading to a breakfast fly-in, located in central Tenn. My pre-flight began with an hour of preheat. The start was quick, as was the warm up, and the flight down was beautiful, and uneventful. After a 1 1/2 hour of breakfast and hangar flying, we were ready to head home. I was surprised at how cool the engine was. It started fine, but I held things up a bit, getting the oil temp up to 120. As soon as it got there, I departed. At full throttle, and at about 50 feet above the runway, the little girl started hollering at me "Engine Speed" Engine Speed" She got my attention! Sure enough, I'm at 5250 rpm, and it is RED, and flashing at me!! Scared the (^@p out of me! I finally figured it out, and it didn't last long. My guess is that the oil was up to temp, but the water wasn't. As soon as I took off, my oil temp must have dropped enough to set off the alarms. I was too busy flying the airplane to notice how far the oil temp dropped, but the alarms only lasted for 10 or 15 seconds. Wheeew! Anyone else experience this?

Piper J3 · #2 11-12-2016, 04:29 PM

What EFIS do you have? D-180 for early SN kit, or did you upgrade to Skyview or Garmin?

RVTrumpet · #3 11-12-2016, 05:48 PM

I've experienced this once. SkyView equipped -12. I was descending at 5500rpm and had intermittent oil temperature readings on the gauge for about a minute, fluctuating rapidly down to zero and back to normal. Every excursion below the magical 120, I'd get the engine speed warning. It only happened once, and I chalked it up to a brief intermittent connection.

KALEWIS · #4 11-12-2016, 08:50 PM

If you depart on a cold day with the oil temps at 120.... the ram air will cool the oil back down below 120 and you get the warnings. No loose connections. I don't think it's a big issue as it will quickly warm up above 120. The run up should be done above 120 anyway, so that should give you a few degrees higher for takeoff. The water temp will have nothing to do with engine over speed warnings. The only caution I know of on skyview is too high coolant temps.

todehnal · #5 11-13-2016, 04:46 AM

I missed mentioning tat this is a Skyview system. Also, my comments about the low water temp on takeoff was not meant to point to it as the cause of the engine speed alarm, but as a possible cause for the brief lowering of the oil temp early in the takeoff run with the oil temp only at 120. My thoughts were that with the higher rpm on takeoff, the water pump could move more cold water through the engine, thus temporarily lowering the oil temp. In retrospect, it was a non event, but the alarm did get my attention.

Pat Stewart · #6 11-13-2016, 06:10 AM

Quote:

Originally Posted by KALEWIS

If you depart on a cold day with the oil temps at 120.... the ram air will cool the oil back down below 120 and you get the warnings. No loose connections. I don't think it's a big issue as it will quickly warm up above 120. The run up should be done above 120 anyway, so that should give you a few degrees higher for takeoff. The water temp will have nothing to do with engine over speed warnings. The only caution I know of on skyview is too high coolant temps.

100% agree with this answer. Here in N. Texas I never had this problem but I am aware of others when taking off in Cold Weather and oil at 120f having the alarm go off as ram air cools the oil below 120f for a few seconds.

Piper J3 · #7 11-13-2016, 07:39 AM

I fly D-180 EFIS and perhaps there is a difference in how the Skyview operates. As an example? my oil temp and pressure have five arcs as follows: lower red, lower yellow, green, upper yellow, and upper red. I can operate in either of the yellow arcs with no alarm. For instance, I can takeoff with oil temp in yellow arc at say 110F and have green arc on tach not opened up yet with no alarm.

Like my grandmother used to say - Such things they have now...

Tony_T · #8 11-13-2016, 08:22 AM

Jim,
You may want to check your alarm settings on the D-180. If you increase RPM above 2500 when the oil temp is less than 122? the normal setting gives an alarm. The alarms can be suppressed in the menus.

mwjohn63 · #9 12-04-2018, 08:48 PM

Quote:

Originally Posted by todehnal

It was a cool morning as we left on our 90 nm flight heading to a breakfast fly-in, located in central Tenn. My pre-flight began with an hour of preheat. The start was quick, as was the warm up, and the flight down was beautiful, and uneventful. After a 1 1/2 hour of breakfast and hangar flying, we were ready to head home. I was surprised at how cool the engine was. It started fine, but I held things up a bit, getting the oil temp up to 120. As soon as it got there, I departed. At full throttle, and at about 50 feet above the runway, the little girl started hollering at me "Engine Speed" Engine Speed" She got my attention! Sure enough, I'm at 5250 rpm, and it is RED, and flashing at me!! Scared the (^@p out of me! I finally figured it out, and it didn't last long. My guess is that the oil was up to temp, but the water wasn't. As soon as I took off, my oil temp must have dropped enough to set off the alarms. I was too busy flying the airplane to notice how far the oil temp dropped, but the alarms only lasted for 10 or 15 seconds. Wheeew! Anyone else experience this?

todehnal,
I made my first flight today in Ohio with temperatures just above freezing and had a similar issue with the oil temps dropping just below 122 on my second take-off climb. Did you figure out a solution to correct this? I'm thinking about adding a shield to the oil cooler to block 50% for starters to see if that helps.

MJ
RV-12, Liberty Township, OH
N418MJ
mwjohn63@gmail.com

Driftdown · #10 12-04-2018, 10:17 PM

Buy a roll of aluminum tape at Home Depot.
Suggest 1.5 inches wide.
It should have an adhesive backing. I prefer the brand which has the light brown paper on the back side, which will be peeled away for use.
Cut a strip of tape, about the width of the radiator.
Apply the strip horizontally, across the top of the radiator. Leave a tiny corner of the strip “dog-eared,” to ease eventual removal (when seasonal temps warm up).
Try a single strip first, to see if that is adequate. If still too cold, add a second strip or at least, an additional shorter strip, until temps increase to a normal level.

That has served me well over the last 4 years.