silver engine 2.0L
or black engine 2.0L
can anyonetell me what one to buy and why??

Silver pre 95 engine if you want to avoid running with injection and a cat, or if you just dont want to worry about emissions
Blacktop is supposedly the better unit, but will require injection and cat to pass emissions, will be more expensive to buy although possibly easier to get hold of

Cheers

Alex

The correct name Zetec-E engine blacktop (black cam cover) zetec (Aug 1998 onwards) is as Alex says supposedly the better unit. The earlier Zetec-E silvertop as fitted to pre Aug '98 Mondeos etc was I think fitted with hydraulic cam followers which could give trouble. The later engine had a variety of improvements.

Don't rule out the other Zetec engine, the Zetec SE (aka Sigma engine) particularly in 1.6 size (Mk1 Focus) and 1.7 size (Puma).

Although intially they would seem less desirable than a 2.0L engine, the Zetec SE 1.6 and 1.7 are all alloy engines wheras the Zetec E has a cast iron block and so is significantly heavier.

Food for thought.

Cheers

Angus.