[STEVE]

STEVE on December 19, 2019 at 9:38 am #19601

That’s very common. I believe it’s because not as much was known about the interplay between EGT and CHT in 1977 as is known today. It wasn’t until 1965 that Al Hundere of Alcor, developed the first EGT probe. The first full EGT/CHT engine monitor was introduced in 1981 by Insight Instruments.
Most airframe manufacturers started offering EGT gauges as options in the 1970s.
Today we are able to fine tune engine fuel air mixtures and take steps to maintain CHTs within reasonable margins which translate into longer cylinder health and life because we know definitively how these factor work in our engines.
Engine monitors are a good investment.

[5 STAR ELECTRIC INC.]

5 STAR ELECTRIC INC. on December 19, 2019 at 5:51 am #19600

My 77 six has no CHT guage. Is this normal? I am having an edm 830 installed as I write this message so that problem is solved. I just can not believe there was not one installed at the factory. EGT but no CHT crazy!!

[STEVE]

STEVE on May 11, 2018 at 8:28 am #18650

Hi Peter;
Sorry for the delay in getting back to you. You’re OK with those temps. This debate will go on forever about the “right” temp but Lycoming has published that 150 deg F is the lowest that is OK. So you’re fine.
If you’re getting lead deposits I suggest that you lean aggressively on the ground. I routinely do my 2000 rpm mag check run ups with the mixture leaned. You’ll know when you’re too lean because the rpm will fall slowly off when on one mag; just richen it up a little and continue.
There is an additive in avgas that will vaporize the lead so it flows out the exhaust but that additive is only effective at higher internal combustion chamber temperatures; aggressive leaning during taxi and low power ops will reduce the lead build up.
But make sure that you richen the mixture up before take off.

[PETER MUCKLOW]

PETER MUCKLOW on April 29, 2018 at 6:47 am #18640

Steve, appreciate your opinions on this if you have the time.

[PETER MUCKLOW]

PETER MUCKLOW on April 17, 2018 at 1:56 pm #18626

I fly a normally-aspirated ’77 Lance that has what I consider to be very low CHTs. Normal operation in summer (85F) shows CHTs in the 300F range (280 – 320). In winter, these fall to the low 200’s (220-250). I have an Insight GEM-610 6-channel engine monitor, with Insight CHT probes. I run ~50F LOP with GAMIjectors. I am concerned that the CHTs are too cool. Should I be? I get lead deposits in the plugs at those temps, but nothing biannual plug cleaning can’t manage.