Automatic Engine??!!

In light of the engine problems involving Robin Leach’s trip down under and Kevin’s comments posted below, I think it is important to pass on some thing regarding my engine and the automatic altitude compensating mixture control that might be of interest to those you out flying.

In late June I took my plane to DLH for it annual check up, admittedly a little early, but I figured better then than just before OSH. I voiced some concern over a number of things many of which were minor, such as the pilot’s door did not open or close as easy as the passenger door, and virtually all were resolved. While most everything seemed to be in order, we talked about how hot my engine would get in an extended climb. I indicated that my fuel flow never has shown 18 GPH at takeoff even at Sea Level as Bill Marvel and Robin Leach experienced on their trip back to the West Coast at even higher altitudes.

As a result Cirrus spent considerable time investigating and adjusting the fuel system. First, my injectors were filthy (likely the result of dirty fuel that fuel filters do not stop) and were cleaned. Second, the altitude mixture control was replaced and/or calibrated. In addition, Cirrus adjusted the throttle/prop control interface. In total, Cirrus ran my engine for over three hours, which gives me the impression that the adjustments and sensitivity take some expertise to make right. It also worries me that if it takes Cirrus that long to make adjustments, how long will it take “mere mortals” at other shops to make the adjustments.

After the adjustments, I now note the engine “sucks” up much more fuel than it did before AND, more importantly, the engine and oil temps are cooler. I am delighted that both of those are cooler and the fuel burn overall isn’t appreciably more than before, but the plane does not fly as fast Â… getting about 155 TAS. The other factor that has me concerned is the engine does not run smoothly at low idle. It, in my view, seems to be running too rich, but the mixture control is “automatic”!? Cirrus and our folks at Del Monte are going to do some more testing and tweaking, but Â…. We’ll see.

As a result of my concerns, I am having a Graphic Engine Monitor installed that includes 6 probes for each of CHT and EGT. I am losing faith in the “automatic system.” I want to know exactly how the engine is performing. The GEM gives you graphic feedback on all six cylinders at the same time. Differences will become apparent right away and you are then better informed about whether or not you engine is being properly “fed” or not. I would suggest to those of you that have any concern that a GEM ought to be considered. Cost - about $2,000. It could be cheap insurance and reduce future engine maintenance bills.

As a result of my concerns, I am having a Graphic Engine Monitor installed that includes 6 probes for each of CHT and EGT.

It’s crazy that you should have to do that - not because the information is not valuable, but because the Arnav MFD already has all the inputs ready for just those probes - what is missing is the software to make it work. So you’re going to have to find space in the panel for another display, instead of it coming up on the perfectly good display that is already there!

Having now had the chance to play with the Arnav, and read the “manual”, I admit to being underwhelmed. This “Multi-Function Display” is in fact a “Very Limited Function Display” that takes up a large amount of panel real-estate for little return.

Walt,

It is funny that you report everything you did in your last email. When you and I got together back in Martha’s Vineyard, I told you that I was not reaching the same gph as you (I couldn’t get much below 10.24-10.5. I also was not getting 160 TAS, but more like 155-158. I also have the rough engine at idle (but not so rough as to make me think too much about it). My bird ran close to the high end of EGT and OT during climb, but never into the yellow or red. Now that I’m in CA, I have noticed its running a little cooler than in MA.

I am not sure that mine is set more like yours is now, but there is obviously a wider range of engine settings than I would have expected.

My most pressing question is:

Why is this engine any different and therefore more un-predictable (dare I say unreliable) than other brand new engines? I am very concerned about this, as it makes me nervous when I fly, taking away, somewhat, from the otherwise enjoyable experience.

I hope that Cirrus and Continental get to the bottom of this.

Christopher

I agree with you about the AR NAV MFD. It has the potential for being so much more, but isn’t. AR NAV needs to get off their duff. As for the GEM I am going to put it in the radio stack above the flap switch. It only takes a 2.25" hole so it should not be a problem. In fact, I am getting used to the idea of having their near the mixture control.

Second the underwhelmed statement. It merely repeats what is already avalable on the Garmins and having 2 of those allows selecting different screens. The moving map on the ARNAV for Europe is VERY limited use, the airspace information NOT TO BE USED in real life as e.g. all D airspace around airports is (standard) circular with the same (standard) radius (which is not the case in real life). Some MIL/CIV dual airports are even missing (example EHKD) from the database.

If (additional and more detailed) engine monitoring would be available, THAT would be a definite plus!

Other than that, am enjoying every second in N144CD…

Han K

As a result of my concerns, I am having a Graphic Engine Monitor installed that includes 6 probes for each of CHT and EGT.

It’s crazy that you should have to do that - not because the information is not valuable, but because the Arnav MFD already has all the inputs ready for just those probes - what is missing is the software to make it work. So you’re going to have to find space in the panel for another display, instead of it coming up on the perfectly good display that is already there!

Having now had the chance to play with the Arnav, and read the “manual”, I admit to being underwhelmed. This “Multi-Function Display” is in fact a “Very Limited Function Display” that takes up a large amount of panel real-estate for little return.

As a result of my concerns, I am having a Graphic Engine Monitor installed that includes 6 probes for each of CHT and EGT.

It’s crazy that you should have to do that - not because the information is not valuable, but because the Arnav MFD already has all the inputs ready for just those probes - what is missing is the software to make it work. So you’re going to have to find space in the panel for another display, instead of it coming up on the perfectly good display that is already there!

Having now had the chance to play with the Arnav, and read the “manual”, I admit to being underwhelmed. This “Multi-Function Display” is in fact a “Very Limited Function Display” that takes up a large amount of panel real-estate for little return.

I finally got a chance to open my latest issue of Flying. In it is a press release that says ARNAV has received FAA approval of its software for engine monitoring. Mentions that Cirrus will be offering this capabilty in the future. I realize that it is sometimes a long way from press release to working hardware, but its probably worth a new phone call.