dogpilot wrote:I have had two 185F's one with the giant 88" seaplane prop. I was defiantly the least liked airplane in the neighborhood when I took off, but boy did it perform. It had a rather high noise to power ratio. My other had the Hartzell Top Prop. The latest version really got you off the ground quickly and didn't awaken Norse gods to throw bolts of lightning at you in anger since it was relatively quiet. Prop choice it kind of what do you want to achieve and where you operate.
As for the engine. the 550 is a more modern, better design. But...to get the horsepower you burn fuel, it physics. I had looked into the 550 for mine, but I am not enthralled with the 550 D conversions. Mainly since there are better 550's out there, mainly the 'N' version, which as New Millennium Cylinders and downdraft induction. It makes 310 hp and is more fuel efficient than the 'D' due to better cylinders, angle valves and less prone to cracking due to better cooling on the head. Unfortunately no STC's for the 185, bummer. If your a long range cruiser and like to cruise over the mountains, perhaps a turbo normalized conversion may suit you better. It does not over stress the engine (just complicates it) and gives you flat rate power to altitude. You can achieve that with your present engine and the bottom line may work out similar. Again, just depends on what you want to achieve. You would end up with a faster airplane with the same performance and fuel burn. This may be a consideration, since AVGAS is rather pricy in your neighborhood.
In my experience, I actually burned less fuel overall in the 550 than in a 520, simply because the 550 runs so happily at LOP, compared to the 520.
Yes, the 550 burns more fuel at max power, but you only need that power for takeoff and initial climb.
Like any engine upgrade to an engine with more rated power, as long as you use the same power in cruise, you’ll burn the same fuel, assuming both engines run ROP.
You use that extra power where it really pays off, takeoff and initial climb.
MTV