Do any of you know what the maximum CHT is for the 6A-350-C1R Franklin 220? All I can find is 392 Degrees in a couple of references. Does that sound right?

Ordering a new monitor and I can't find it anywhere.

Thanks in advance!

Jim

Its 390 according to the tcds.

http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/e4be5adaba76f70186257ba60052d994/$FILE/E9EA_Rev_13.pdf

TangoFox wrote:Its 390 according to the tcds.
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/e4be5adaba76f70186257ba60052d994/$FILE/E9EA_Rev_13.pdf

It might be worth noting that the max CHT temp specified is based on using a bayonet thermocouple type sensor.
FWIW the Continental O-470 TCDS calls out two different CHT limits for bayonet probe vs a sparkplug gasket type probe.
For the 470K it's 460 degrees vs 525 degrees-- quite a difference!

The 220 Franklin in the Maule has a service bulletin to place a sleeve around the CHT probe which is to contact the bottom of the hole in the top of the cylinder. This was to get a more accurate reading. Operators handbook says 390 F but does not stipulate the word "maximum"

I think 390 is the number. I'm using a bayonet type probe.

Thanks for the help guys!

Jim

hotrod180 wrote:

TangoFox wrote:Its 390 according to the tcds.
http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/e4be5adaba76f70186257ba60052d994/$FILE/E9EA_Rev_13.pdf

It might be worth noting that the max CHT temp specified is based on using a bayonet thermocouple type sensor.
FWIW the Continental O-470 TCDS calls out two different CHT limits for bayonet probe vs a sparkplug gasket type probe.
For the 470K it's 460 degrees vs 525 degrees-- quite a difference!

The Franklin 165 is the same way.
530F for Sparkplug type
445F Bayonet type
310F Cylinder barrel

IMO you should grab a copy of the Franklin 220 Operating manual. As hotrod180 pointed out, the spread is large, making assumptions isn't worth it.