Thanks to everyone for those links to other suppliers and for your
comments. They were all well noted!.

Yesterday I talked to my car mechanic about continuous duty engines. He said
they did not really exist but likened it to aero engines which are required
to run for long periods at a time without missing a beat.

"Yes" he said "they are built to exacting specifications and components are
replaced after a recorded period long before they fail."
"What about old VW and Subaru engines which are used in home builds" I asked
"They are usually rebuilt or modified by dedicated and highly competent
amateurs and maintained to a very high standard" the mechanic replied.

So. A continuous duty engine is one that is well built (ie almost any new
engine) and maintained to a high standard (hey I do that to my car already).

It's all in the maintenance!.

Steve