Hi All PLEEEEAAAASE help
I have a nova 1.2 carb cerca 91-93, this is a long story but i will try to keep it brief!

I bought it 15 months ago, very good engine no noises run sweet as a nut, after 4 months started over-heating, I thought it was due to the hot climate out here (mallorca), no sighn of oil water mix, filled up the water after a few days same problem this time very slight sign of oil/water mix, took head off cheched gasket, gone around first cylinder, cleaned head and block v.v tiny mark in cylinder head but no where near cylinder water jackets, rebuilt and put on new head gasket, ran sweet as a nut, for roughly 3 months, then it went again! now thinking it may be a warped head but no means of engineering workshops out here, so we tried yet again with a new headgasket, and then it did it again after 3/4 months, after a LONG search (s/h parts not easy to get here either) we got a cylinder head but it was off a later model and injection, changed everything on the head except the valves incluiding cam followers and hydrolic lifters, reasembled it all, then realised when it started injection head has an extra air intakeas there is no way of using injection manifold decided to seal off the air intake, engine started first time but developed a major rattle, thinking maybe pistons were topping out on valves for some reason, that was the kind of noise, have just removed head AGAIN! no signs of topping out or anything untowards, now completely void of ideas!!!

I need to try and stop it from sounding like a tractor unit
can anybody help a damsel in distress?