I am not quite sure why, but rumors suggest that the _modern_ overhead
cam
and multi-valve engines are far less tolerant of sloppy or deferred
maintenance than most older designs.

If this is the engine I am thinking of, there has to be a special low
coking
oil used, or the cam chain tensioner suddenly loses its ability to
maintain
tension, and the whole thing flies apart, catastrophically for the
further
running of the engine. Regular oil, even changed every 3K miles will not
cut it.

From what the Chrysler mechanics (and independents) I've talked to
about this say, following the extreme driving schedule using either
top quality dino or synthetic oil solves the problem. On these engines
(2.7) there is NO driving that is not "extreme" as far as the oil is
concerned. They can, and will, go over 300,00km with proper care. Are
they fussy? without a doubt - but PROPERLY maintained, they CAN be
relatively reliable. Would I put one in a plane????? I'd have to think
long and hard on that one - I think there are too many other, better
alternatives.

Very interesting, and sounds a little unusual for a non-turbo engine. But
there are obviously too many good alternatives to waste much time on an
apparently marginal engine.

I have heard that the GM 90 degree V6 engines are essentially bulletproof,
but also quite heavy, and that the similar ford engines had (several years
ago) a weakness in the head gasket area, but have been popular conversions
for their overall combination of weight, strength, and power.

Have you heard any recommendations for or against the Chrysler 3.2L and
3.5L, the GM 3.4L, or the similar Ford engines. There is also a Chrysler
3.7L engine in the Jeep Liberty, which should have enough service history to
make an evaluation. It would seem that the 60 degree engines should have
been developed to the point of being at least as reliable as the 90 degree
engines--but much lighter.