Could somebody tell me or point me in the right direction for the min aircraft requirement in order to do an IMC/IR(R) in my own aircraft?
The IR(R) syllabus requires a "suitably equipped dual control" aircraft. Suitably equipped, I would suggest, for the part of the syllabus being taught. CAP 804, Section 5, Part E, page 2.
For the IR(R) test, the requirements are in
Standards Document 25(A) para 2.2.
Can I do it if the engine is 'on condition'?
CAA guidance about Flying training and testing in Private aircraft is in AIC W001/2011; although, this information is out of date for group owned Permit to Fly aircraft.
ifitaint...