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How hot does your CHT temperature run in hover and cruise? Redline is 500 degrees F and in hover with two people mine gets pretty warm-about 440. It cools right off when you set it back down and run at 2000 rpm( to about 380 or less if you set there longer). For those that have Celsius gauges 227 C is 440 F.

We have one of each type.

The Celsius one runs about 220° or so during hover, or right at set-down. Maybe 205-210° at cruise At 2000 rpm cools down to 180° within a minute and then at idle its down to 150° or so within another minute or less (2 minutes max time). My first one also was usually 210-220 max at cruise, and only slightly higher depending on how far the mixture was leaned. Here's a shot in cruise, during the summer, mixture leaned. The other is about 375° max (hot day), but usually closer to 340-350 or so, depending on outside temps. I have seen it at 325° during cruise. During cool down it will stabalize around 310-320 within the 2 minutes. I don't think I've ever seen it get to 380°. Here's a shot of this one on final approach to land earlier this year.

Thanks Ron. Your first one runs very closely to what I'm seeing when converted(seeing about 405 to 410 cruise). Your second one is running cooler. I have two cht gauges one digital and one analog-both probes are on the number #3 cylinder. One has a "well" type probe(digital) and one has a sparkplug type ring probe. They both agree closely though which is quite surprising give the difference in probe types and gauges.

If Ron would snap a pic of the GEM 602 in 75U, you could see all 4 on a plasma bar graph along with all 4 EGT's.

ED my temp is running abought same as RONS.you can check it with a foto thermometer.just shoot at a cylinder head.there pretty accurate....