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When to leave the Nest

L

Larry

Active Member
My first flight was 12 Aug 06. So far I have only put on 5.2 hours on the aircraft, all orbiting above the airport. I only fly on weekends as the airport is 85 miles away. :( I have a new Penn Yam Aero O-320. Does anyone have a feeling how much risk I would be taking if I leave the close vicinity of the airport? Is there a high probability the engine could fail during curise within the first 10 or so hours? I have a Dynon EMS and I am watching all the temperatures. I am still working elevated oil temperature. I manage the power so my oil temp does not exceed 230 deg F with an OAT of 80, but I understand that is not good for break in. On takeoff I use full power but for cruise at 8000 density altitude I have to keep RPM to 2300 or less. The plane fly very nice but its getting boring up there. I can not even shoot touch and goes. Not a happy camper at this time. :( Do I just got to slug it out for ??? hours?
 
Oil temps

Larry,
Can you tell us about your oil cooler setup? What type cooler/how many flues and where is it mounted. If firewall mount, what size scat tubing to it?

5.2 hours on a Penn yann would be plenty to venture further away but the oil temps are a little high. Kindly give us more info,
 
Standard Vans RV-9A oil cooler installation. Oil cooler mounted on the baffling behind Cylinder 4. The oil cooler is the standard oil cooler from Van's FWF kit. 7 oil passages. I understand a Stewart Warner oil cooler would do much better. Maybe I should buy but not yet, cost about $475 and not sure will do the trick. My baffling is good, I have clear continuous ware marks on the top of the cowling from the baffling material and I have looked very close to see that the seal is good. I have made the modification to the top cowling that prevents air going past the sides of the inlet turbulence reducers but have not check yet if there is any improvement in temperature due to that. Red RTV all over and no opening between cylinders I have loaded the latest SW for the Dynon (01.06) that is suppose to fix oil temp sensor calibration (Dynon saids that the old SW can cause a 10 to 20 deg higher reading). I saw no significant change. The EGT are high also. On average 1 is 360, 2 is 420, 3 is 430, and 4 is 430. I run rich all the time and have checked the plugs and they look good. I do not want to screw up this engine and this is causing me to fly very gingerly. No fun at all.
 
I'm sure there are many more expert in motor break in than me, but, here's what I would do first.
Verify that your oil temp gauge and sender are working correctly. Remove the temp probe and put it in something you know the temperature of. i.e. Water boils at 220 degrees F, so you could put it in water and heat it up and watch the gauge.
I would be concerned about running a new engine at such low power settings during break in. Typically, engines should be run at higher power settings, if possible, until the rings seat, which would be indicated by a reduction in engine temps and reduced oil consumption. This is usually done at lower altitudes in order to get maximum manifold pressure. (Make sure you use the recommended oild for the break in. This can vary by manufacturer.)
The temps you describe would be typical of CHT. I believe that most engine manufacturers recommend you keep them below 400 degrees for break in, if you can.
In my case, having broken in several engines, I feel safe enough to stray from the airport after about 1.5 to 2 hours of uneventful flight; however, it's prudent to always be heading toward another airport, at least for awhile.
 
Hot engine

I was the guy that alerted Dynon to the oil temp calibration issue. I found it of course by doing the boiling water thing. I have not rechecked with the latest software. I would definatly do that if I were you...Its pretty simple and could save a lot of worry.

Secondly, check out Walter Tondu's cowl ramp mod where he found a significant imptovement in cooling by glassing in the side of the ramps.

I don't have the Van's cowl but these are the two things that hit me when folks talk about cooling.

Frank
 
Larry,
I know the feeling. My -9 with a PennYan O320 had its first flight July 1. Now I have 16 hours on it and the engine hums along just fine. I need to watch CHT's on initial climb but they settle into an acceptable range at cruise. My oil temp has never been a concern. I am using a IK Technologies engine monitor.
My DAR gave me 5 hours around home and 35 within 40 miles of home. That is a lot of time in the same airspace so I have been to almost all the local airports in that area and spend time playing with the GPS and generally just getting used to the plane.
I would not worry about your engine as long as temps and pressures are where they should be. Go have fun and try to do something different with each flight.
 
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