Single 180 year 1959 poor cruise performance ?

[Paul Michel Fenouil]

Hello,
I ask only to Single 180 owners. Mine cruise at 110 Knots (126 MPH) with O-360-A1A 23 inch 2400 RPM 8.8 Gal/h, altitude: 1000 ft . Is this normal ? On the new ICS POH page 5-3 it is said 139 Kt (in fact 139 Kt is top of Green arc and bottom of Yellow, not an usual cruising speed) . Page 9-7 World Record #2 Casablanca (Morocco) to El Paso (TX) 6053 NM 56.4 Hours - the average speed was 107 Kt (123 MPH).
The only modifications of my bird are Osborne Tip Tanks and PPA Dual Exhaust stacks. The rest is of origine.
What is your usual cruising speed and settings ? Does anyone have any idea of the number of PA24-180 in service ?

Thank you to help.

Michel
from West Africa

[Barbara Shaffer]

Michel, We love our 180 because of the fuel burn,speed and the cabin.At 1000 msl ours might be a little faster at that power setting but I have found that it does much better up at 7 or 8000 msl. Up at that altitude we run full throttle and 2400rpm and always get between 137 and 142ktas and burns around 9.5gph. Our 180 does not have any speed mods yet but we are planning to do some. We normally fly with 2 adults a 40 pound dog and bags. Thanks!

[Timothy Quigley]

We had an issue in our 260B where the IAS was way lower than we'd expect per the manual. Turned out the plane was doing just fine but the airspeed indicator was bad. If the numbers don't add up, triangulate with ground speed using a GPS (even if just a cell phone) on a calm day. It may just be the gauge rather than actual performance.

[Paul Michel Fenouil]

[Paul Michel Fenouil]

[Zach Grant L1011jock]

If the aircraft is truly this slow there is something else significantly wrong. Check rigging, gear rigging, cowling nose baffles and internal baffles. Also rough paint makes a significant difference in the 180. If your paint is not smooth as glass in the laminar flow area of the wing, you will loose 5-7 mph right there. I have no issues getting 150-155 kts true airspeed out of mine, but I have extensive modifications.

[Paul Michel Fenouil]

[Barbara Shaffer]

Zach, Have you shown a list of the speed mods on your 180 here on the forum? Thanks

[Zach Grant L1011jock]

I have listed them in the past somewhere but here are the big items:
K2U flap and aileron gap seals
K2U Wing root fairing and fillets
Lopresti speed spats/slipper
Single piece W/S
Aviation Performance Products Eagle Cowl w/dual exhaust
PA-24-260 single fork gear
Late model wheels and brakes w/hubcaps
Mac 3 bld scimitar prop
Metco Air wing tips
Sealed wheel wells
Optimized baffles and cooling air exits
Electroaire Electronic ignition

It isn't as easy as just bolting stuff on and getting the airplane to go faster! Each one of these items works in a different way. Very few work effectivly at increasing top in max speed at sealevel. However most help the TAS at altitude so you realize the gains above 7K'.

Zach

[Will Berninger]

[Joshua Dickson]

Good topic! I have a '59 180. 2 blade Hartz. prop, electro-air ignition, newer paint. I get 140knots at 8k 24 squared full bag of gas with just me in the airplane. I have been mulling over speed mods like the Cowl and the seals but am saving up for a better GPS and autopilot first.

[Pat Elliott]

I flew Friday evening. 23" 2300 = 120knts at sea level. 1960 PA24-180.
I have really crappy paint.

[Will Berninger]

[Quint Van Deman]

If you are looking for data points I pay more attention to cruise speeds in the 6-8k range, but I too get 135-138 knts true (2 blade prop, 180, no speed mods of note).

Cheers,

-Quint

[James Turner]

Hi All,

'59 -180 with some speed mods and a very tightly rigged gear (with reversed brake mod). I set power based off my JPI using 75% power.

At S/L I see ~128kts TAS/IAS. 2350rpm MAP for 75%
At 6-10k I see 140-141 kts TAS. WOT with RPM for 75% (at 10k this is 2500).

James.