"Fred W" > wrote in message
...
> Cords wrote:
>> I had unfortunate incident at a BMW dealership. Whilst sevicing My 1997
>> 740 4.4 litre the technician accidently dropped the screw top of the
>> spark plug into one bore. Needless to say on start up destroyed the
>> head and scored the cylinder. The dealership now wants to machine the
>> bore and put in a metal liner.
>> Is this possible on a aluminium alusil engine?
>> I would have thought the correct thing to do would be to replace the
>> block or the entire engine!
>>
>> Any advice would be appreciated
>> Cords
>>
>
> No. You can't resleeve an engine that does not have sleeves. The Alusil
> or Nikasil engines are alloy blocks with a very thin coating in the bores.
> Not sleeves.
>
> They will find this was a very expensive mistake. New short block, new
> head. Big bucks.
>
> --
> -Fred W
These engines are made from an aluminum alloy that has copious quantities of
a very hard material (forget which one). Anyway, a very thin layer of hard
material forms the wear surface. Go through that, and you are left with
aluminum which is a very very very poor choice for wear.

Jim