RV-9A XIO-320 EGT Sensor Location

24Golf · #1 07-05-2009, 07:31 PM

I have searched here & there with no luck... it is time to install the EGT sensors and can't seem to find the right place. Here is the problem: on Cyl 1 the exhaust turns immediately towards the other side this would allow connection after about 3". On Cyl 3 the welded joint connection starts about 2.0" from the flange and goes down for about 3" to the 5" location. Cyl 2 is straight for 3" then the welded joint takes up the next 3" down to the 6" point. Cyl 4 is straight for 4" the starts a big turn. This is the vetterman exhaust that Vans sends with the 9A FWF kit and will be installed with the Dynon probes. Dynon says to install 2" to 8" from the exhaust flange and all sensors must be the same distance away . There is no common single distance that I can set the probes that would allow for equal temp measurement. You other 9'ers - please help!

THANKS

N941WR · #2 07-05-2009, 07:38 PM

Paul,

Check out the two pictures on the 11/4/07 entry of my 3rd engine page.

There is plenty of room to install the probes. Just make sure you angle them backwards. If they stick out to the side they might touch the cowling.

24Golf · #3 07-05-2009, 07:57 PM

Bill,

Thanks for the photos... your exhaust looks just like mine EXCEPT that the top of welded joint on Cly 3 is now only 2" from the flange (Vet must have changed something). This would put the probe about 1.75" down from the flange on Cyl3 and right in the middle of the bend on Cyl 1.

N526JS · #4 07-05-2009, 08:06 PM

I just got done installing my EGT probes. IO 320 and Vetterman exhaust. My installation looks a lot like Bill R's. On the #3 exhaust stack if you place the probe clamp just at the welded fitting then the probe is very close to 2" from the flange. On #1 stack it is OK to put the probe on the bend. You just have to estimate where the probe tip will end up so it is 2" from the flange. On cyls #2 and 4 the pipes are straight so there is no problem. In the end, each cyl will have its own range of readings that you can trend monitor anyway. My opinion only as I have not operated this set up yet.

Good Luck.

Jim S.

N526JS · #5 07-05-2009, 08:09 PM

OOPS. I just posted at the same time as your reply to Bill. Hmmm, that is a problem with the 1.75". Maybe you can call Dynon and get input on the probes being that close to the flange.

ClayR_9A · #6 07-05-2009, 09:02 PM

Install your CHT probes, spark plugs and wires BEFORE drilling for the EGT probes. If you angle them too much, they'll interfere with the spark plugs.

You should probably even have the cowl done.

there's really no need to drill these until almost everything else is done, and it is best to wait until you know there will be no interference.

24Golf · #7 07-07-2009, 12:09 PM

Thanks for the help... I will probably put off the install for a while till I fit the cowling - I still hate putting that #3 EGT so close to the head!