High CHT finally solved

After 10 years, my high CHT temps have been solved and my high oil temps have been improved.

My new carbon fibre cowl incorporating a square filter assembly has improved the performance hugely. I attribute the majority of improvement to the removal of the seaplane lip and running the lower cowl all the way to the firewall. A mate of mine who was instrumental in testing a locally produced aircraft told me that he believes that the seaplane lip creates too much turbulence at the point of exit which restricts airflow.

Pre mods, on a hot day I would see CHT temps over 400F and oil temps up to 230F. Post mods, CHT temps 360F and oil temps 210F

After


before

thanks for the updates!

I doubt the lip is a turbulence problem, but more of a "blocking" problem creating dead air area that is easier for the outside lower cowl air to suck from than pulling through cowl and cylinder fins....

i can stand a foot from you with a sucking vacuum cleaner hose... you won't feel a thing...

yes getting rid of the gap on lower cowl probably was key, you could probably extend a plate forward from bottom of boot cowl, towards/closer to lip and get same improvements.....

There are some STC’s that require the air dam to aid in cooling. Many of us have found that the air dam creates a vacuum aft of it which allows more hot air to escape from the engine compartment.