much more than replacing the loops plugs. Loop plugs usually require
replacement every 75kmi or so (they become MUCH less effective as they
age). Parallel plugs usually last MORE than twice that long.
You may be right, I've had dead parallel plugs and not any dead
series plugs, but I've much more experience with the former.
Parallel
plugs deliver all the heat (~700 Watts) they generate to the
prechamber,
A series plug puts about 55W into the prechamber. A parallel plug
about 144W.
while with loop plugs, more then half of the heat is dissipated into
the
air OUTSIDE the engine thru the resistance wires that couple the 1st &
2nd and 3rd & 4th plugs.
I've long thought that if only the toaster racks were located inside
the intake manifold where the waste heat could be used to heat the
incoming air charge the series system would be just as effective as
the parallel system. It's an experiment I've been longing to conduct,
but may never get around to. The mechanics of putting the toasters
inside the manifold such that _nothing_ can ever break loose is what
holds me back more than anything else. If this 240D were going to
stay with us I'd be tempted to try it out there. The 200D (the other
candidate) is such an easy starter anyway that I don't know how much
I'd learn from doing it there.
A slow starter WILL result in poor starting (especially when temps
approach freezing), but that much less common then the other problems.
It was what was wrong with my first car, a Falcon. We'd replaced
_everything_ and it was still hard to start, to the point of
stranding you sometimes. A new starter and it made a miraculous
difference. The old one didn't sound particularly slow, except
when compared to the new one. And it also drew a lot of current,
sucking down the battery to reduce the spark.
-- Jim
