” 2 / 2 ” – EGT sender location

Builders,

I use the short hand ” 2 / 2 “ to note a Corvair motor which is set up with 2 CHT’s and 2 EGT senders.  My own personal aircraft is set this way, with one CHT on the bottom of each head in the stock location, and one EGT sender on each other the exhaust pipes. This is pictured below.

.

.

Above is the pilots side exhaust pipe from my aircraft. The single EGT sending unit comes just after the #2 cylinder exhaust port. It is on the inboard side of the pipe to have a cleaner appearance and simplify wiring. This particular sending unit is an Auto Meter 5249, which can be used either as a clamp on or (as pictured) a welded on installation. I chose to put one of these in each side of the exhaust, but I run a DPDT switch under the Auto Meter gage allowing the one instrument to be fed by either sending unit.

.

Many Corvairs flying today use Dynon or GRT glass cockpits to effectively monitor “6/6”, for traditional instrumentation, “2/2” makes sense to me and provides effective coverage, information for leaning, and an opportunity to look at right/left comparisons. Because this takes just 2 more probes 2 switches, it makes a lot more sense that a “1/1” system. One of the things that I find ironic is when a low time pilot tells me he “must” have a “6/6” system. I’ll ask him what he did his flight training in, and it is often a Cessna 150, and I will ask him how many CHT’s and EGT’s that plane had. Very few of these people remember that their training was done in a plane with a “0/0” system.

.

I strongly recommend against anyone even thinking of flying a Corvair with a “0/0” system. We had a guy try this 3 years ago. He had also designed his own cowl and cooling system and was at an airport with a base elevation over 5,000′. The 2 questions that should come to your mind are “How would he know if the cooling system worked without a CHT gage?”  and “how does one lean a Corvair if you have no EGT information?”  I don’t have answers for those questions, and neither did the builder. First flight was 25 seconds long, landing was upside down in a farm field. No serious injuries, but it did make TV news, where the builders buddy took the opportunity to blame the motor right away.

.

If you are thinking of a “2/2” system, read the stories below. If you are thinking about Glass Cockpit stuff, and want to speak with the most experienced people on Corvair/glass 6/6 arrangements, Call Rachel and Dan at 904-626-7777 , ext. #1. They mostly sell GRT stuff, but they do have experience with all of the systems.

.

Inexpensive Panel……..part one.

.

Inexpensive panel…….part two.

.

Thought For The Day: Mechanical Instruments

.

-ww.

.

 

 

 

 

.

.