Li-2 mixture reversed?

[FTC_Mars]

Hi all, I did some flight testing of the Li-2 and observed some strange results.

 

At 500m I observed that the engine develops more power and runs cooler at 0% mixture.  It overheats and develops less power at 100% mixture.  It behaves like the mixture control is reversed: 100% mixture behaves like an over-leaned engine, and 0% mixture behaves like a rich mixture or auto-managed engine.

 

Test conditions:

Quick mission Moscow

500m altitude

Autopilot on

Throttle: 100%

RPM: 100%

Mixture: held constant at 0% or 100%

Inlet and oil cowls: 100% open

 

0% mixture:

max MP 1100 mmHg, max CHT < 200C, max oil temp < 90C

 

100% mixture

max MP 1080 mmHg, max CHT > 200C, max oil temp > 90C