Wideband Air/Fuel Ratio Meter and Lycoming

[David-aviator]

As I gather parts for the BPE Lycoming, a wide band A/F ratio meter is on the list for consideration. (cost about $280) It is capable of recording on a lap top just about everything one would want to know about the engine in terms of EGT temperatures, rpm, manifold pressure and A/F ratio.

Has anyone used such a device on the Lycoming engine?

[airguy]

By A/F ratio, do you mean it measures the exhuast gas for oxygen content, similar to modern automobiles?

[hgerhardt]

Originally Posted by David-aviator

...a wide band A/F ratio meter is on the list for consideration...Has anyone used such a device on the Lycoming engine?

It used to be that the oxygen sensor (Lambda sensor) wouldn't tolerate leaded fuel for very long before before it was lead-fouled. Don't know if the new ones are better, but that would be worth investigating before purchase.

Also, you'd want to have a common exhaust collector (4 into 1), or you'd need two O2 sensors for the typical Van's crossover system.

Heinrich Gerhardt
RV-6, flying

[rv6ejguy]

Any device using the Bosch LSU 4.2 wideband sensor in conjunction with leaded fuel might not give accurate results for long. Typically we find wideband sensor life a lot shorter than the older narrow band types. Bosch literature says life may be reduced by about 75% at lead concentrations exceeding 2 grams/ gallon. I've seem them die in as little as 5 hours on leaded race gas.

Not sure that this would be too useful if you already have EGT on all four cylinders but it would be interesting indeed to compare AFRs with EGT.

[RichB]

I agree with Ross re the sensor life with leaded fuels, but for anyone running unleaded mogas in their engines, WBO2 could be a useful arrow in their engine monitoring quiver. There are PDA (Palm / PocketPC) apps out there for various models too, so you might be able to rig up something cheap to monitor/log it in the cabin...

[David-aviator]

Thanks for the information...I knew about the lead issue but my brain had it packed away somewhere.

I do plan on using 100LL until things settle down with the engine so the A/F ratio system is way back on the back burner.