Thank you all for your replies. The following is interesting and I would dearly value some input.

I have now finished the model and flown it. I placed the motor 1/2" below the datum.
The maiden flight needed some 15 clicks of up elevator. The model flew nicely, no problems on landing.The wind was strong and variable to do much analysis, so I figured that with the engine thrust line being moved down and having to trim with up elevator that some engine up thrust may be desirable.
I added up thrust:- a washer on the bottom of each side of the engine mount on the firewall - approx 1ml (3/64")
I then had 2 more flights and needed to add another 3 clicks of up elevator.
In these 2 flights I performed only loops and rolls and was not able to adequately do too much serious testing as the motor is still running in.

The model is an 84" low wing, with a flying tail plane.
The engine is an ASP 180, with 16x8 prop. The model weighs approx 14lb and the CG is in the middle of the specified range.
I would appreciate some help
Cheers
CdeJ


The model proba