Thread: High CHTs
View Single Post
Old 10-24-2016, 09:57 AM
paul330 paul330 is offline
Join Date: Feb 2007
Location: Mpumalanga, South Africa
Posts: 1,065
Default High CHTs

My Aerosport IO540 D5A4 is running beautifully - except for the CHTs.

All is well apart from the rear two cylinders. In the climb (at 120kts as opposed to best climb 100kts), they get up to around 430F. In the cruise, all is well until I lean. At peak EGT, they creep up to around 415F. To get below 400F, I need to enrich to about 15gph. The other 4 cylinders stay below 400F. Nothing gets above 435F.

So, all are within limits but I understand that below 400F is desirable. The baffling all looks good and well sealed. At the rear, I have the standard VANS set-up of air to the oil cooler, heating duct and two mag blast tubes. I have cut off the entire front dams.

How can I get the rear cylinders to run cooler?

(The engine has about 50 hours and appears to have run in with oil consumption very low - no oil added since the last change some 12 hours ago)
Mercy Air, White River FAWV
RV-10 ZU-IIZ - "Zeus"
Building Bearhawk Bravo - RV-18 not available
2019 Donation Made
Reply With Quote