Engine Ops Knowledge Source

Having flown my first cross country yesterday (250 miles round trip with 1 touch and go), I found myself with time to fiddle with and pay attention to some engine parameters.

While running at a 75% setting, (roughly 24 squared), I found that if I lean the mixture to about 10.2 GPH or so, the motor runs fine, but the CHTs creep up and will go past 400 degrees. At one point, I'd richened it up to about 12 GPH to keep the temps at around 390. Strangely, on the return trip, at about the same power setting, I was able to run it at 10.2 GPH and the CHTs sat at around 360 to 370.

I'm running a horizontally injected 360 with P-Mags and a Whirlwind constant speed prop, and the motor now has about 12 hours on it.

I'm guessing that the drop in CHT is indicating that the motor is now broken in, but the fact is, I know so little about engines, how to run them and what things are red flags that I'm a bit uncomfortable in the ignorance.

As with everything else concerning this project, when I get to the time where the knowledge is required, I then become very interested in acquiring it and I absorb it better, which brings me to the actual point of this post.

I know that there are lots of little bits and pieces scattered throughout these forums about lots of different questions, but learning it in dribs and drabs isn't a horribly efficient method for me.

So I'm wondering if ya'all could point me to a trusted, definitive, comprehensive book or series of articles or such that would give me a well rounded knowledge of all that I should ever really need to know on running and maintaining my motor, including lean of peak ops.

I just know there is such a resource and that you guys can point it out much faster than I can stumble around and find it.

Thanks in advance,

One basic premise with engines is that the more efficiently you are burning the fuel, more of the heat energy is being used inside the cyl to move the pistons.

Example: If you have a well balanced mixture and an ignition timing advanced enough (as can be produced with the Pmag), the fuel charge is burned more fully during the power stroke of the engine which means more heat is transferred to the cyl head, vs some of the burning still occurring as the exhaust stroke begins, which instead passes some of that heat out through the exhaust port.

Study this chart until the relationships are clear.

Make mixture settings using EGT in relation to peak EGT. Park it in one of the gray bands. Don't park it between the bands, in particular at high or oversquare power settings.

That's most of what you need to know.

Jesse, I had the same issue. I found Mike Busch's EAA webinars quite helpful to educate myself.

I have enjoyed reading these articles:

http://www.avweb.com/news/pelican/182146-1.html?redirected=1

#63 - #66 are about where to run the engine.

Advanced Pilot Seminar

I took the online version of the Advanced Pilot Seminar (see http://www.advancedpilot.com/onlinecourse.html) and thought it did a great job of explaining what's happening in your engine. Some of this is in the avweb articles by John Deakin as well.