I had these cowl flaps installed while my IO550-D engined 182-G amphib was waiting on a prop rebuild. (I posted the prop story in the MT prop thread.)

I previously experienced high CHT's (400) when climbing off lakes on even moderately warm summer days, necessitating lowering the nose and accepting longer, slower climbs. I had to replace cylinders at under 800 hours, despite my best efforts. (I bought this plane with 200+ hours on a new engine and prop, so I don't know how it was previously run.

Horsham claims 50F lower CHT's. I was skeptical, so yesterday I was pleased to put them to the test. I departed a 4500' lake with OAT 90F, and proceeded to climb 500 FPM nonstop to 8500' with the hottest CHT reaching 354F briefly. IAS in the 84-95 MPH range. In the higher, cooler altitudes, all cylinder temps dropped. Most around 315-320. This is with large, draggy floats (Aerocet 3400).

Very pleased. Game changer for me.



http://www.horshamaviation.com.au/Produ ... wlFlapMod/

I have no affiliation with the vendor. I paid the $700 list price and my local A&P billed 4.5 hours.

I don't plan much cold weather ops, but maybe partially obstructing the air intakes?

Pierre

Very nice. Never heard of them before. How was your oil temp? Were you able to get it high enough?

+1 for this mod, it's just about mandatory in Aus. Tony and the team at Horsham are thoroughly decent guys as well

Oil temp was fine (180-190).

With the matched GAMI injectors and individual EGTs on the JPI, you can still tune the mixture to get any EGT from <1200 to >1500 and run rich or lean of peak.

My SOP is lean warm up and idle taxi, rich for high power water work and climb. and lean cruise.

Pierre

+2 I’ve been running these on my pponk E model for several years after one of my old flaps departed the airplane somewhere over the San Juans. Never had a cht over 375.

I’m actually worried that it’s running too cool after reading this months savvy maintenance article. I routinely see chts in the 320 range while cruising.

I don't own a 182 so this is more out of curiosity, but are they still controllable? The picture looks like they are fixed but might just be the angle. I'm lucky that my scout has very low CHT's. Highest I've seen is 340. I know I put the baffle seal wrong after re-cowling if I see higher. Glad your problem is solved, 50F ain't no joke.

asa wrote:I don't own a 182 so this is more out of curiosity, but are they still controllable? The picture looks like they are fixed but might just be the angle. I'm lucky that my scout has very low CHT's. Highest I've seen is 340. I know I put the baffle seal wrong after re-cowling if I see higher. Glad your problem is solved, 50F ain't no joke.

These are fixed in place. I did make the little lips that are riveted on in the photo removable on my airplane. I install them in hotter oats to create more cooling.

We made a very similar flap for our Bearhawk with the Landrover motor and we hinged it so we could open and close it from the cockpit. It worked OK but not as good as we expected so we did some wool tuff experiments and found the air was coming around the sides and trying to go back in the opening. We made some small contoured side plates and extended them back about a foot. This stopped the air from trying to go back in and just about doubled our cooling effect with little to no extra drag.