I have 5 exhaust valves that are leaking on this annual.  Compressions are all at acceptable levels (62-76).  8 exhaust valves have been previously done.

Running LOP 70 degrees or less of peak EGT at 31”, 2500 rpm with GAMI injectors, head temperatures are at 300 in cruise. TCM TSIO 550E1B, 925 hours.  I have the Micro Vision monitoring with no data logging.   I climb with high fuel flows (35gph) and low temperatures (max 360 heads)

I have gone to the GAMI course (Advanced Pilot Training) and believe I am doing everything correctly.

What am I doing wrong?

Running LOP?  Running to hard LOP?  Have had poor rebuilders do the pervious work?

So what do I do? 

Is this engine rebuild time?  The cylinders look fine with a boroscope examination.  I will know more after the heads and cylinders are pulled.

Have all the exhaust valves, seats and guides done again?  If so, who are the credible shops to do this?

Start over with an engine rebuild?  Nothing else looks wrong with the engine.

Put in new cylinders, heads, pistons and rings?

Oil consumption is 1 qt every 20 hours.  Exxon oil.

Insanity is to continue to do the same thing and expecting the outcome to be different.

Insights, suggestions, strong opinions are all welcome. 

Thanks,

Carl Cadwell

N25CL  Lancair IVP