CHT temps

[201kb]

Hello, 

I recently purchased my 1978 201 .  My #3 cylinder gets around 405 to 420 on the CHT temp..All other cylinders are hovering around 360.  Is this normal.. My EGT stands around 1400 or less.  Enriching or leaning doesnt seem to change the CHT temp on the #3 cylinder.  Can you advise if this is normal..?  

 

Matt

[Jeev]

Quote: 201kb

Hello, 

I recently purchased my 1978 201 .  My #3 cylinder gets around 405 to 420 on the CHT temp..All other cylinders are hovering around 360.  Is this normal.. My EGT stands around 1400 or less.  Enriching or leaning doesnt seem to change the CHT temp on the #3 cylinder.  Can you advise if this is normal..?  

 

Matt

[Parker_Woodruff]

I assume you're leaning rich of peak?

 

How is that EGT in relation to the others +/- dF?

[Cruiser]

Cylinder #3 has the factory installed cylinder temp thermocouple. (required per the minimum equipment list in POH) what type of thermocouple is being used for your monitor? If it is a spark plug ring type thermocouple I would not be surprised at this reading. You may have to do some checking to find out what the readings on #3 are telling you. Different locations give different readings. i.e. top spark plug is usually hotter than the bottom plug, I would recommend a piggyback type thermocouple that can be added to the factory location. It will give a closer reading to the others and better for comparing with the other three.

 

TomK

[Chris White ex-N205KD]

I think the general rule is anything over 400 is bad.  We were running in the 360's LOP in 5KD in cruise all cylinders, cowl flaps closed.  The only time we saw anything close to 400 was in Vy climb in the summer.  I really think your baffles need looked at, you have a probe problem, or you're in the "red box" ROP.

[MooneyMike]

As mentioned, FIRST, check where your probe is located.  I struggled with the some problem until I talked to the folks at JPI who told me the probes measure best when using the bayonet style and located on the bottom of the cylinders. 

If your fuel flows are good, 15 - 18 gph on climb out, 10.5 - 11.5 in cruise and baffling is fitted correctly, suspect your instruments and work from there.

Best wishes,

Mike

[231Pilot]

My #3 also runs 50-70 degrees hotter than the other cylinders.  My mechanic suggested having GAMI send a new injector for that cylinder to increase fuel and lower temperature.  Is there anything else he should be considering?