Looking for 170B engine conversion STC's

[blueldr]

When you're thinking about engine conversions and fuel economy, keep in mind that any given airplane configuration presents a certain amount of "Flat Plate Area" to the relative wind. No matter what engine is installed, it will take the same amount of power to move that airplane with that FPA at any given airspeed. Almost all of the currently available aircraft engines have very nearly the same specific fuel consumption. (pounds of fuel per horsepower per hour) As a result, any engine installed, no matter what the horsepower rating, will provide the same fuel burn at a given airspeed.
When I changed my engine from the 300 cu.in., 145 HP Continental to the 360 cu.in.,210 HP Continental, the fuel burn at 115 MPH was the same. The really big advantage was in the climb to cruising altitude. From a take off at 1600 ft. MSL to a cruise altitude of 9500 ft. , the time went from an average of 35 minutes down to !! minutes using a cruise climb of about 90 MPH. Of course, you had the choice of using considerably more cruise power with a higher fuel burn for a higher speed. You will have to do some experimentation to find what speed gives you your your best nautical miles per pound of fuel. In my case, my Cessna 170B seems to like about 115 MPH.

[GAHorn]

Put another way, an engine that quickly gets you to an altitude where you can take advantage of reduced temps, better wx, reduced fuel burns and yet still make sufficient power at that altitude to keep a decent T.A.S. is a pleasure.
(I'm generally happy with the original O-300 in this airplane, until I travel to convention across the western deserts/mountains during summer months. This was never intended to be a high-altitude business transport. But it makes a pretty reliable, if slightly underpowered, family machine. Man, I wish we had a current-production, all-metal, adjustable prop. It'd not likely be a huge sales success, but it'd be so nice to dream about owning it.)