bent heater plugs

Anyone know why my heater plugs(79 series 3 Landy) in the number two
cylinder are get warped and squashed. I replaced one about a month ago.
Within a couple of days the new one suffered the same fate. The coil on
the plug appears like it has been sort of squashed and bent at the same
time. Maybe it has been hit by the piston/valve. I bought the plugs from
Paddocks and they are the standard plugs. An NGK plug next to on the
number 1 cyclinder seems to have a slightly smaller reach into the
cylinder. Engine runs smooth/ no missing/starts easy on 3 plugs/no
smoke. I did have some knocking happening just before the first plug
gave up but that seemed to be linked to a fuel cleaner. Im not really
looking forward to spending part of a weekend removing the head to
inspect the cylinder and head.

Regards
Coops

"Coops" <[email protected]> wrote in message
news:[email protected]...
> Anyone know why my heater plugs(79 series 3 Landy) in the number two
> cylinder are get warped and squashed. I replaced one about a month ago.
> Within a couple of days the new one suffered the same fate. The coil on
> the plug appears like it has been sort of squashed and bent at the same
> time. Maybe it has been hit by the piston/valve. I bought the plugs from
> Paddocks and they are the standard plugs. An NGK plug next to on the
> number 1 cyclinder seems to have a slightly smaller reach into the
> cylinder. Engine runs smooth/ no missing/starts easy on 3 plugs/no smoke.
> I did have some knocking happening just before the first plug gave up but
> that seemed to be linked to a fuel cleaner. Im not really looking forward
> to spending part of a weekend removing the head to inspect the cylinder
> and head.

Hot spot in the head loose?