A couple of comments on diesels for CL aerobatics or sport flying. This is what I think about diesels this week, and I may change my mind on some of it next week.

Properly adjusted, the diesel will hum along in level flight. It will run the same through maneuvers. If it slows in maneuvers, it is overcompressed; if it misses in maneuvers, it is a hair too lean. I wouldn't run anything but a uniflow tank which will give you consistent fuel feed from beginning to end. People complain that diesels are not consistent for aerobatic competition. I think this is because people change things between flights. Once I get a diesel (or glow engine) running right, I try to leave it alone. With most diesels this means leaving the compression set too low for easy hand starting, so I use a starter if needs be. Because diesels are very fuel efficient, a slight tweak in the needle will change run time for a particular tank much more than with a glow engine.

When I fire up a diesel, I expect it to run ragged and undercompressed while I walk out to the handle and put the safety thong on. But by the time I am ready to signal for release, the engine should be warmed up and running very nice. If it is running nice when I am half way to the handle, I expect it to run through the flight a little overcompressed. If it is not quite there when I am ready to fly, I expect a burp or two an the first couple of laps but then it is supposed to run fine from then on.

I may tweak compression just a hair, based on how the engine flew, and how the exhaust looks. I won't usually change the needle valve, unless I want to regulate run time.