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Permalink Reply by JEFF COCHRAN on August 4, 2016 at 3:35pm

Bob,

I used the Dynon 180 on my 750 STOL.

For CHT you have three choices, all J-type thermocouples.  14mm ring for the spark plugs, 10mm ring for a 3/8 bolt in the stock GM locations under the heads on cylinders 1 and 6, or custom spring loaded probes that goes into the stock GM location.  I know Roy S. sells these probes.  For what it is worth, here is my recommendation.  Forget about cylinders 1 and 6 if you are only going to measure 1 or 2 CHT's.  For one, I would put a ring on spark plug 5.   For two I would use spark plugs 4 and 5, or 3 and 5.  If you want to measure all six, go with one on each plug.  If you measure under the plugs you get a slightly higher reading.  For example, my CHT red line is set at 380 measured internal in the head.  The plug reading is about 25 deg. higher, so you could set your limit at 405.  I ran all three locations on cylinders 1 and 6 concurrently to see what the difference in reading would be.  The bolt locations on 1 and 6 were 50 degrees cooler, so your limit would need to be 330 degrees.

 

For EGT's you need K-type thermocouples that go into the exhaust pipes and clamp around with an 1 1/2" SS worm clamp.  You have to drill a 1/8" hole for the probe.  One EGT in the combined down pipe gives you a number to look at and not much more.  One EGT in the individual exhaust pipe close to the joint will let you compare numbers on just that cylinder, but no clue as to what the other cylinders are doing.

 

For oil pressure I used a VDO 360-004 in one port.  Dynon also sells both pressure and temp probes.

For oil temp just about any auto probe that will screw in (I don't remember the number).

Tach sensor just search the Flycorvair and Corvaircraft sites for opinions.

For manifold pressure you would need a bung welded on the intake pipe.

Dynon sells a temp probe that will screw into the carb.

Good luck with your wiring, its fun

Jeff

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