Turbo F Aztruck going into annual this week.

I've suspected for a while that my RE TIT inaccurately reads about 100* low. So, while in annual and with the nacelles off, I thought I'd replace the sensor/probe that measures TIT.

The reason i think this is...because RE cht's, egt's and oil temp typically run slightly higher than LE (normal for Aztec i've been told) yet TIT is lower at exact same fuel flow.

Can anyone shed light on exactly what component I should replace and perhaps what the part number might be? Would it be a Garrett PN?

Thanks for any insight.

Mark

HI Mark,

I'm sorry I can't help on the TIT probe, but I'm curious about the difference between the RE & the LE engine temps. Can you explain why it's normal?

I'm observing the same behavior in my (new to me) turbo model E and I was wondering if my engine monitor was acting funny - it's a worn out Gem 1200 whose display works half of the time, so I'm going back to the factory gauges, but still.

The only thing I know about probes is that they need to match the gauge's brand. We recently put a new CHT probe on the RE that we connected to the legacy digital CHT and it went right to redline after starting the engine. I found http://comanchegear.com/FUEL%20SYSTEM/S ... gauges.pdf after installing the probe

Of course it's only after posting this that I think of searching the forum - just found viewtopic.php?f=3&t=93867

I replaced my JPI 760 with the new (and much cooler) 960.

Attached is a picture from this past weekend.

As you can see, RE TIT is lower while other temps are slightly higher.

The reason i say its typical is for 2 reasons. First a friend of mine also flies an F Aztec and see's the same situation, and....John Talmidge at Diamond Aire says RE's are just plain hotter.

It's a stretch but perhaps a reason for RE hotter than LE is in the airflow. The TIO540-C1A has the prop control unit in front of the #2 cylinder and significantly covers the air inlet surface area on the side of cylinders 2,4,6.

On the RE, that air inlet is adjacent to the fuselage, while on the LE it is the outboard side of the engine and not subject to air flow disruption/contamination from the fuselage AND blocking the air inlet from the prop control unit. Like i said, its a stretch and a theory.

Otherwise they should operate identically.

Thanks for these explanations! I definitely need to find a replacement for my flaky GEM1200 and run some experiments myself.

Go JPI...its good data and that what you need to properly love these big block turbo's.