Hello Ronald,

I agree the one power setting at FL110 with MAP33.8 and 20.8 gal/hr might not have been a very good idea – as I said I won’t do this again (it was still LOP on all cylinders). But the engine at this time for e.g. seemed a lot happier than with the power setting at FL230 with MAP31.9 and 16.3 gal/hr

First I determined my TIT peak temp (Craig Berland gave me really good instruction here) – it turned out to be around 1720

After the climb I level off the plane and let the airspeed build up. Then I pull the mixture back within on second until my fuel flow is in the 16 gal/hr range. I can feel the loss of power there. My TIT is then usually 1500…1550. I know that I am on the lean side then. Then I keep adding fuel until my TIT is 1600…1630. I’m always using the higher TIT which is always TIT#2. Write down the TIT, the fuel flow and the MAP. If you do this several times you get to know your engine and you will be able to predict what your engine will do depending on your input.

Ralf

Hello Craig

I am surprised about your stats, as I recall fuel flow values between 19 and 22gph were the area’s where the engine gets really beaten up? I might be wrong, but on my last flight I tried just to see where it peaks (TIT) and was actually surprised that it peaked at a lower TIT than before.

In other words, if you use ‘your TIT temp’ as your gauge than this might be off as it does change with altitude and OAT.

Now I am still not very comfortable looking for peak (even going from the lean side) but it will get your surprised sometimes. I usually go smooth and fast (within 4 secs) and then I just know it was higher, but by how much I do not really know as I do not want to be in the red box too long.

Now in the past I was leaning on a much smaller power setting like 60%, and when I knew and was less than 80% LOP I just bumped the throttle back to 75%, but I am not even sure if this is the right or perhaps totally wrong way.

But some of the values in your chart looks like dangerous territory….I just hope I am wrong with my assumption.

So my questions:

Were you always leaning and if so did you do this at that power setting?

Did you lean on TIT or first/last cylinder? (depending from which side you lean)

From the lean side or rich side?

== Ronald (>400hours IVP, n45HL, the rest I do not count lol)

Hello Craig,

Thank you very much for your picture. I got a lot of information out of it and spent quite some time looking at it – you can feed me a lot more of these before I will get tired of it…

I kept a log of my power settings on different flights for the last year and I found one setting that is very similar to yours – unfortunately I didn’t get that good of a tailwind

My fuel flow shows a little less – may be this is a calibration problem? My TAS shows higher – but mine comes from the bezel and is influenced by friction heating and air compression – it would make me very happy if someone on the list could give me a correction factor for my speeds/conditions.

When I put my scribbled notes in a spread sheet and sorted it to altitude and OAT I found something in my opinion very interesting: on the lower altitudes the OAT has very little influence on the speed. At the higher altitudes (>=FL180) you can clearly see how the airspeed decreases with increasing OAT because I need to run the engine at lower power settings to get similar TIT and CHT.

On low altitudes (<FL120) it seems I can feed my engine a lot more fuel without significant influence on the CHT (may be because of my plenum) - The high power setting at FL110 was more than 1.5 years ago – I kept it in there for reference and I won’t do this again

On some warm/humid days I just have the feeling my engine doesn’t like it at altitudes higher than FL190. I don’t like higher than FL230 because I don’t have winglets and it doesn’t feel that firm anymore

Info for the chart: TIT is my TIT2 - it is usually 40F warmer, TIT max is around 1720, warmest CHT is always #2 and CHT#1 comes close after it, the TAS comes from the bezel and would need to be corrected, all settings were in cruise for at least 45 min or so – sometimes up to 2 to 3 hours.

Ralf

From: marv@lancair.net [mailto:marv@lancair.net]
Sent: Wednesday, October 16, 2013 3:47 PM
To: lml
Subject: Re: IV-P Recent Trip