After burning up a head on my Corvair engine, I learned two very valuable 
lessons recently.
1. When all your troubleshooting has not come up with an answer for high CHT 
and nothing you know of has changed, the basics of fuel and air remain the 
same.  I kept running high CHTs and just could not find the answer.  After 
trying everything... twice, I found the problem.  A tiny nick in an o-ring 
inside my aerocrab was leaking fuel, but only in the mid to high throttle 
settings.  The tiny loss of fuel happening there was undetectable to my Dynon, 
left no smell of fuel in the cockpit, and could only be seen with the eyes 
running the engine with the cowling off.  The new part cost 84 cents.  I bought 
2.  Digital systems lie.  My "red cube" fuel meter ran great for many years.  
Since returning Goliath to a pump-powered fuel system vice gravity feed the 
cube said I was burning 7-8.5 GPH in cruise flight, with occasional take-offs 
reading 9+ GPH!  Testing by running the fuel system into a graduated container 
and through measuring actual consumption against the cube's reading showed it 
to be 20% off!  If you are flying by what the cube says vice what your EGT/CHT 
says, eventually you will find yourself in trouble.
One other factor for all of you flying Dynon gear.  I recently had my FlightDek 
back at the factory for a reburb.  They replaced quite a bit of the guts in the 
box, as my system was 5+ years old.  This may have contributed to the readings 
being off as well, but there is no way to be sure if it was the reburb, or fuel 
With a new o-ring and calibration of the fuel flow, everything is great.
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