More on CHT

[flyboy0681]

I ran into Mooney test pilot Bob Kromer on Saturday when I attended an open house at the Piper facility in Vero Beach in celebration of their 75th anniversary. He said he saw the lone Mooney parked on the ramp and was curious whose it was.

We talked for a while about various subjects and I asked him a question that is always discussed here; maximum CHT. He said that the IO-360 can safely and continuously run with temps up to 400 without having to worry that you are going to fry the engine. He also added that if you can crack the cowl open even an inch, that should give some relief without compromising speed.

He was a very affable fellow and I wish I had more time to chat but I had to move on.

I took a tour of the factory and was amazed at the operation. Prior to stepping foot in it I thought most planes were put together from sub-assemblies shipped to the factory by outside suppliers. Fact of the matter is, the only thing that goes in the front door are rolls of aluminum. Every part is fabricated onsite and made into an airplane on the spot. The final assembly line of the PA-46 family was incredibly interesting, but man it was a lot of walking.

[rbridges]

do you think the 400F would apply to the O-360 engines, too?

[Lood]

400 deg be it then, but I'll continue not to let any CHT on my engine come close to 380 deg.

[rbridges]

400 deg be it then, but I'll continue not to let any CHT on my engine come close to 380 deg.

380 is also the limit I use. 210 for oil.

[Earl]

When I get above 380 degF in my hottest cylinder I open the cowl flaps a little until the highest cylinder is closer to 370 degF or below. While 400 might not damage the engine if you can run the engine cooler why not do it?

[fantom]

Bob Kromer is a test pilot, was Mooney President for a while and Director of MAPA. He is a most interesting and well versed guy. He is not however a mechanical engineer. He is, or was, a ROP only guy.

400 may be fine, if you sure it's 400. Calibration errors in every individual component along the line is uncertain. Keep those CHT's to 380 or lower for peace of mind. Otherwise, if you have issues between 380 and 400 send the bill to Kromer or flyboy

[flyboy0681]

Don't shoot the messenger, only conveying what the man said.

I try to keep it between 360-375, assuming the JPI is accurate, which I believe it is. Before starting I cycle through all of the cylinders to check the ambient temps and the readings are usually within a degree or two of each other and the installed OAT reading.

[aaronk25]

You running rop or lean of peak??? Also do you have the cowl flaps set to Be open. 1/2 a inch to 1 inch???

If you never let the cht exceed 400 and limit most operation to 380 preferably 360 and run weekly I bet you will be able to get 4000 hours out of your cylinders....2 over hauls worth mine Busch has done just this with his 310 he is about 3600 hours on 9 of 12 cylinders on his 79 Cessna!

[aaronk25]

One other thought if you cruise at 435 have fun replacing cylinders every 800-1200 hours.