National Aeronca Association Bulletin Board

I just bought a 1946 7AC with the Lycoming 0-235c1 engine conversion ......... Is there an STC for 0-320 on this 7AC ?

Here are all of the current STCs for a 7AC http://aeronca.celinaux.com/STC/7AC-STC.pdf

Here are the current STCs for any 7 series http://aeronca.celinaux.com/STC/7-series-STC.pdf

You can get to an O-290 with service letters 56 and 60

Service Letter 56 http://aeronca.celinaux.com/SL/SL-56.pdf

Service Letter 60 http://aeronca.celinaux.com/SL/SL-60.pdf

Ok Great !!! If you take the aircraft into experimental status, does that allow for modifications to make the engine produce more HP ? Is there an exhaust system that we could buy to get more power out of the 0-235C1 or 0-290 ? Can we use 0-290D2 ?
Thank you !!!

Moving the aircraft into Experimental is tougher than you might think. They're just not going to let you bolt a PT-6 on the airframe with-out some kind of justification. You might want to consider a later model Citabria like a 7KCAB or GCAA for the power you need. The 7AC will perform just as these other aircraft when the added power is installed.

Ok, I am at an airport in the SouthWest that is typically density altitudes of 7000 to 8000 feet middle of the day ! I heard that this 0-235C1 will be a very good engine for the given altitudes but of course we always need more power if possible !
Why is it difficult to bring the aircraft into Experimental status ? FAA ? Paperwork ?

My experience is that with 115 HP (o235 / Don's Dream Machine etc.) and a seaplane (climb), prop you will probably do fine, just don't overload the airplane.

Bob

The FAA will want to know the purpose for the modification before they approve a special issuance certificate. Experimental don't meet the FAR's and are issued the Experimental certificate. The Aeronca meet's the FAR's so you would need to approach it from a different angle. Installing an O-320 would require the engineering necessary to satisfy the FAA. In the interim they could issue a special issuance certificate that could be used for flight testing, based on the information provided by the applicant. At completion of the flight test phase the modified aircraft will be returned to it's category if approved. If the modification is not viable the aircraft will need to be returned to its original condition.

Paul

One thing I wouldn't do is add that much horsepower (0-320) if the plane was not recently rebuilt and all the steel etc. checked. I have seen too much hidden corrosion in Aeronca's that I have owned to be cavalier about that.

Also keep in mind the required spare inspection openings or special inspection requirements if you put in anything over 100 HP.

Bob

Ok guys ............. Thank you very much !!! All points taken well ..............