Aeroinjector WOT too rich?

[lpaaruule]

Glad to hear you got it figured out.

If my EGT climbs to 1400F on climb out, I just back off the throttle about 50RPM; the temp comes right down.

[builderflyer]

I talked to one of the Rebuilders of the 3300 and he pretty much confirmed what you guys said. He said that 1200 to 1350 is normal EGT and that sensor placement can be a big factor why they are reading higher. Cylinder 1 and 2 are very sensitive to placement.

Regarding EGT sensor placement..............I once ran an experiment where on cylinder #2 I installed 2 sensors an inch apart (3" & 4" down from the flange) on the header pipe. There were rumors floating around then, and apparently now, about how critical sensor placement was in regards to the measured EGTs. There were two runs done with the sensors reversed in the second run to account for the error in each individual sensor. The results of my tests showed that there was less than 10 degrees difference in the readings obtained from sensors installed an inch apart from each other. This is rather insignificant with absolute temps measuring well over a thousand degrees. Has anyone else run this experiment? It would be good to know that someone else has independently come up with the same findings before accepting them as valid, and perhaps, putting these rumors to rest.

Art,,,,,,,,,,,,,,,,,,Sonex taildragger #95,,,,,,,,,,,,,,,,,,Jabiru 3300 #261

[lpaaruule]

I haven't done that experiment, but the moderator on the official Jabiru forum said stated something very similar to your results. The big issue with placement is keeping it far enough away from the "flame front"; which is why they now recommend a further probe placement than they used to.

Below is what I'm referring to:
https://jabiru.net.au/service/technical ... /#post-234


question:

I see from JSB 18-2 page 10, that the EGT sensor should be installed 120 mm from the face of the exhaust.

In my Storch HS the factory installed the single sensor approx 50-60 mm from the exhaust of left rear cylinder. How will this typically effect the reading? Higher or lower temperature? How many deggrees +/-?

Answer:

I think the 120mm minimum is mainly to ensure the reading is stable, to extend the life of the sensor and get it away from any standing flames coming out of the port.

I would definitely expect the reading to be higher, though probably not by much - a wild guess would be 0 to 10 degC higher.