skywagon8a
MEMBER
SE Mass MA6
Yes, he was one of them. I had several flights in different programs with this same FAA pilot and got to know him quite well. Definitely a 50%er.Maybe he wanted a 50th percentile pilot. Plenty of them around.
Yes, he was one of them. I had several flights in different programs with this same FAA pilot and got to know him quite well. Definitely a 50%er.Maybe he wanted a 50th percentile pilot. Plenty of them around.
I've had the IO-520 @ 2850 max of 300 hp, intercooled TSIO-520 @ 2700 max of 310 hp and the IO-550 @ 2700 minimum of 300 hp all in the same 185. The IO-550 is clearly the better of the three. Pulls better from the start, climbs better and cruises faster. On top of that it is smoother and quieter. The turbo will clearly perform at much higher altitudes but overall is an inferior engine.To the earlier comments about a 550 making more oomph than a 520, guys I know prefer 300hp at 2850rpm to 300hp at 2700rpm for takeoff performance.
To the earlier comments about a 550 making more oomph than a 520, guys I know prefer 300hp at 2850rpm to 300hp at 2700rpm for takeoff performance.
Takeoff performance has little to do with efficiency.
I've had the opportunity to play with prop speeds and temperatures to reduce the supersonic tip speed drag. My experience regarding performance is not consistent with the graphs that seem focused on noise. Fly at a DA of several thousand feet below sea level on a short strip with tall obstacles. Dial the prop speed down to fit the speeds on the Pponk tip speed calculator. Note the crossing height relative to obstacles. Repeat without reducing prop speed. Note the improved clearance over obstacles. More noise? Absolutely. In sub-zero temps at sea level the noise coming from a plane operating on a creek bottom is deafening. I say cover your ears because I'll take the improved performance over the trees every time.
This thread has moved way beyond the original question about a PA-12.
I agree; major difference, just like between the 85 and 90 continental. The 160 is much more powerful and burns less fuel.Oh, man... Ten HP can be an incredible upgrade... A few years ago, I owned a Grumman Traveler (150 HP 4-seat predecessor of the 180 HP Tiger). In our Texas summers, it was a dog when it came to climbing... Didn't help that I'm a "larger than average" guy, and so is my son who flew with me a good bit, but we would see about 450 fpm at "best climb" airspeed – even less at cruise climb.
So during a particularly good annual inspection (that's one where your IA finds nothing wrong!), I decided to go ahead and spring for the high-compression upgrade (STC) that converted the engine to exactly the configuration of the O-320 160 HP models.
From the very first flight, I noticed a HUGE difference in the rate of climb. I picked up at least 250 fpm - with the only difference in the plane being the 10 added HP. My static RPM was about 150-200 rpm higher than before, but the most surprising thing to me was that I was burning almost 1 GPH less fuel at the same airspeeds. I almost didn't believe it myself, but when I added up all the fuel used before the upgrade, divided by the total hours flown, I was averaging 8.0 GPH for that block of almost 100 hours. After the upgrade, I flew the plane another 75 hours, and the average fuel burn was 7.1 GPH for that block of hours. I didn't change the way I flew - cruise climb to altitude, and use the same cruise speeds (same RPM setting).
I think the fuel savings came in two areas:
1) Faster climb meant less time climbing to altitude at full power.
2) The higher compression engine was just more efficient at cruise power (2500 rpm or roughly 65% power).
The "Grumman Guru" who recommended and performed the upgrade for me said I would have seen even better results if I has also switched from the original McCauley prop to a Sensenich prop that was significantly more efficient than the Mac... But since my prop only had 106 hours on it since new, I couldn't bring myself to spend the money for a different one...
So, yeah, if one of the airplanes had a "stock" 150 HP engine, and the other one was 160 HP, I would expect the 160 HP plane to accelerate faster, get out of the water sooner, and climb and cruise much better than the other one!
Start with this: http://www.kenmoreairharbor.com/upl...per_pa-18_series_aircraft_extruded_struts.pdf
Look in the lower right circle of figure 1 at item 4-7. On page 2 item 4-7 is 88-C-706 eyebolt.
EDO drawing 89-C-703 "installation mod 89 spreader assy" This drawing is included with the installation package for ALL 1650, 2000 and 2130 float installations. That means ALL installations of these models.
On this drawing there is a note: "Note - shown for front spreader-reverse eyebolt with shank on these lines for rear spreader, with chamfer facing down."
Why not use a dial indicator and measure the cam lift at the rockers or valve springs?drain carb
swap carbs, mags plane to plane..
still got all cam lobes on bad performer?