Differential Fuel Burn question...

[scottygofast]

Hello all..

Just wondering if anyone else has had a similar problem with their 337. On a 5 hour flight, I had a 15 gallon difference in fuel burn between the front and rear. The only fuel burn/quantity info I have is standard cessna gagues and the front egt is inop. Ive been leaning the mix according to the POH, any both levers are in the same position.. any ideas what might be going on? I did notice a 10 min difference in fuel burn time when exhausting the 18 gal aux tanks, but dont know how to explain any further? Thanks!

[Roger]

How can you lean to POH standards with an inop EGT ?

[Gord Tessier]

The best way to answer that one would be to invest in an engine monitor. The position of the levers, though even. does not mean the settings are the same. An engine monitor will tell you right away if you have a cold cylinder and a host of other issues that you can't tell otherwise. I had a rear engine failure and was able to detect it almost immediately because I could see the cylinders going cold. It may have saved my life as I was bout to go over water.

[larry bowdish]

Fix The Egt!!!

[larry bowdish]

The good news is you weren't too lean. Obviously running way rich of peak.

[Ernie Martin]

I agree that you do have to get the EGT gauge fixed to properly lean per the POH, but if you are coming close to leaning both engines per the POH* , my main concern is that the 3 gallon per hour difference may be a problem far worse than unbalanced leaning. You might have a tank leak or, even worse, a leak elsewhere in the fuel system. I would have this looked at ASAP.

Ernie

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* Coming close is doable even without an EGT gauge by an experienced pilot, familiar with both engines, using the standard fuel flow gauges, relying on the roughness that accompanies peak EGT, and then enriching from peak EGT by the same flow rate needed to enrich the other engine after its peak EGT.

[Walter Atkinson]

What is "too lean?"

The only mixture that is "too lean" is one that will not burn--that's WAY LOP--and called Idle Cutoff.

If one is "not rich enough" on the rich side of peak EGT, the CHTs and ICPs can be dangerously high. I'm thinking that's what you meant. Right? Not too lean, but "not rich enough."

As for the engine monitor... it's clearly the most important engine management tool you can have. It will pay for itself many times over in reduced maintenance costs and can save your tail, too. They tend to pay for themselves "all at once!"