Aresti

Took me while to work that out too... I will Measure the firewall centre asap and post piccy at the same time but....the cowl frame is glued to the front of F1 and then I glued some small blocks of hardwood backed with balsa triangle , you will have to sand the frame a little to get it perfect and the cowl fits over the top. Basicaly this gives support all the way around the edge of the cowl and you then screw into the hardwood blocks....pictures will make clearer as soonas I can post I will.

To centre the engine mount I first cut the prop driver hole out of the cow and the cyno'ed the engine as near as I thought looked right for length and then basically mounted the prop and spinner and kept taking it all apart and moving everything until I was totally happy with the position.from there you can mark the engine bolt centres and engine mount centres and bolt it all up...again pictures will help and I will measure my centre....but be careful as every cowl will be slightly different again picces will help as soon as poss