Hi Forrest - interested in your 'up high' numbers. In my 601P with the same configuration as yours (intercoolers, short props, 300HP) - I can get 14.5GPH (55L/hr) with %#$@ sitting around 1600. TAS is about 217kts (I don't normally fly higher than FL210 - takes too long to get higher)

I wonder why you're hitting limits so much earlier?

S1A5s with intercoolers. i have a long wing light 601B. We run 10-12k 24", 2200 rpm 13gph/side 200KTAS

I have TIT probes on all four turbos, and one runs about 30-40 deg hotter, no one knows why (it is an accurate temp), or how to get that one turbo to run a bit cooler.

That's a bit weird I'll agree. My left engine is 20-30F hotter than the left but both TIT probes are within 1-2F of each other.

Thanks for the LOP replies, very good info - I appreciate it!

I have TIT probes on all four turbos, and one runs about 30-40 deg hotter, no one knows why (it is an accurate temp), or how to get that one turbo to run a bit cooler.

It's tightly packed in there.

I have TIT probes on all four turbos, and one runs about 30-40 deg hotter, no one knows why (it is an accurate temp), or how to get that one turbo to run a bit cooler.

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Is that a common aerostar issue? Could be cowling or accessory placement differences?[/quote]

I understand LOP, took the online course, and have had Gami injectors in my last three airplanes. I think Gamis are worth every penny LOP or ROP, but in those three airplanes LOP simply provided no real benefit.. In the Mooney Bravo, it brought a very high performance airplane to a near standstill. After installing Gami's in the 601P, I found the "benefits" almost negligible. What I didn't like about it was the high TIT's. After "trial-not so much error", I found that leaning the 601P by TIT's is quick, simple, and produces the engine operating numbers that I like. I usually lean to about 1575 TIT and find that, for some reason, the left engine burns about 1 gph more than the left at the same TIT numbers. At 60% power, set up like this, I am burning about 30 gph and getting 210 knots in the 15,000' range. My CHT's run around 320 to 330 with #4 on both engines being the lowest, sometimes below 300.

I don't pretend to have any expertise other than owning one or more airplanes continuously since I was in my 20's, over 30 of them. I never overhauled an engine before TBO and in that time replaced three cylinders, all on carbureted Continentals. That does not include replacing all four cylinders on my O-200 powered Cub because of sticking valves: a common problem with old O-200's because of high lead, "low lead" fuels.

My personal, uneducated, dumb ass opinion , is that most people make way too much noise over variable engine numbers. So many factors go into how a particular engine number is transmitted from the engine to the instrument that there is lots of room for error. The important thing is to know your engine, keep it within manufacturer's limits, and identify trends of change. The one thing I am certain of is that running high cylinder or turbo temps will cook something fast.

I am absolutely not trying to tell anyone how to operate their engines; simply saying how I have successfully operated mine long before there was any common knowledge of the ROP/LOP envelopes. If you want to debate ROP/LOP find someone besides me because I don't give a rat's ass how you run YOUR engines.

I will close this post by saying that one of the things I love about the Aerostar is its ability to provide incredible performance and baby the engines at the same time. At 60% power it is hard to hurt anything but the turbos, with high TIT's.

Jgreen

The Aerostar LOP Mafia must reply! Here is a graph from mine, Lyc IO-540-S1A5, big turbos, Machen intercooler, standard (long) Hartzell prop.



The upper two lines are the %#$@ for the two turbos on the engine. During leaning they go slightly above 1650 deg F. No problem, that is a continuous limit, not a momentary limit.

The next yellow line is the EGT for cylinder #4. It basically follows the same pattern as the %#$@, as expected.

The other yellow line is the CHT for cylinder #4. It goes from about 400 deg F in the climb (a little warm, yes, it was a hot day) to 365ish for a couple of minutes while ROP, then the dramatic and steady fall to the LOP value below 340. I thought this one curve is a great example of the result of the lower peak inter-cylinder pressures and a longer power curve on the downstroke one sees during LOP operations...if you know what to look for.

And the best is the blue line - fuel flow, going from climb FF at over 25 gph to a little under 14 gph while LOP. I get the same speeds as the others - 26" 2200 RPM 27ish GPH total and about 210-215 KTAS at FL190.

Norman,

You will have to interpret a little more for me. So, what are you TIT's at the cruise you are specifying.

At 19,000, my airplane will hit 220 easily burning 30 gph with TIT's well below 1600 and CHT's all below 350.

Jgreen

For the example shown, %#$@ are about 1600 degF. My left engine does not have GAMIs , but the right one does. I could use some improvement on my GAMI spread, will need to correspond with John-Paul this spring on that.

Your numbers are great, I run slightly more lean that you (I think).

Norman,

Truth is that much of what we do is "cause we wanna". Some guys are what I call master tinkerers and have the patience to turn everything they do into an art. That's not me. Engine management to me is finding parameters that will deliver consistent performance and reliability quickly and easily and staying there.

My ROP numbers can be improved with careful LOP operation. I simply don't care to go to that much trouble.

When I transition from climb to cruise, I set power and then TIT at about 1575; I'm through. And happy.

Jgreen

Tripped over this....? ( I'm not looking, thought there might be interest)

https://www.govdeals.com/index.cfm?fa=M ... cctid=5389

Jeff

Aerostar makes an appearance in the movie American Hustle.

As much as I love my Aerostar, I didn't notice anything else in American Hustle except for Amy Adams....