PA11 Engine approvals

[janberghoff]

I am looking at a PA11, and the owner said it has a Lycoming 0-235. When I inquired about whether it has a STC or 337 he said it doesn't need one because some PA11's were manufactured with the Lycoming 0-235.....? He has owned it for years and has always had it annualed but he said there is no 337 or STC on record. I thought the PA11's only had C-65 and 90 HP engines. I have heard of 100 HP PA11's but they were modified and approved using a 337. I don't even think there is a STC for a 100 HP PA11....? Any comments?
Thanks,
Jan

 

[djfraudman]

See the type certificate data http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/5C679681565DE939852567390045D9B1/$FILE/a-691.pdf

VI - Model PA-11, 2 PCLM, Approved April 30, 1947. See NOTE 7 regarding conversion to 2 POLM.
Model PA-11 is generally similar to the J3C-65 except vertical location of engine mount, cowling, forward fuselage structure,
types of seats, fuel system (including gas tank location), lift struts, required equipment, and eligibility of certain equipment items,
as listed. Elevator bungee (Piper Drawing number 80352) must be installed in order that the aircraft conform to the pertinent
flight requirements.
Engine Continental A-65-8F (See Item 311D for optional engines)

Engines and Engine Accessories - Fuel and Oil System (cont.)
311. D.
(6) Lycoming O-235-C Use actual weight and arm
Eligible on landplane only and when installed in accordance with Piper Dwg. No 12447.
Engine Limits: All operations, 2600 r.p.m. (100 hp)
Fuel: 80 minimum octane aviation gasoline.
Oil Capacity: 6 qts. (-31)
Propeller Limits: (with propeller, Item 10 or 11 only)
Static r.p.m. at maximum permissible throttle setting:
Not over 2450, not under 2250.
No additional tolerance permitted.
C. G. Range: (+12.9) to (+17.3)
Aircraft weight and balance should be checked to determine need for
11¼ lb. ballast at (+179) or limitation to solo from rear seat only.
Placard required in full view of pilot: "All acrobatics, including spins, prohibited."

 

[T.J.]

Yep:
fraudman is correct, it is approved.

 

[janberghoff]

THANKS for the response....

Hey guys....thanks for the help.....I'll check out this cub.....and maybe I will be a happy owner of a PA11 soon......!!
Jan

 

[T.J.]

delete

 

[JimC]

TJ, an O-235-C1 adds about 6 or 7 percent of gross weight over the 90 for a 20% increase in climb power (and 100 hp continuous). An A-65 is lighter than a C-90 or an O-200, so using this line of reasoning you'd be better off yanking your 90 and installing a 65.

Jan, There's nothing wrong with the 235 on the 11. I'm removing an O-200 from my 11 in order to install my O-235 on it (I wanted the O-200 on my J-3 more than I wanted it on the 11). At worst, he might have to placard it for 'solo from rear only'.

All the best,
JimC
P.S. TJ, I'm with you about the rear seat ASI. If one wants it, why not.

 

[Crash]

A friend of mine had a real nice flying PA-11 90hp. Put an 0-235 in it, bigger is better, right? Wrong...after flying the plane for awhile he switched back the the C-90. Said the 0-235 ruined the plane. Felt real nose heavy and couldn't slow fly it as well. Crash