>

  >> Lots of (most?) modern automotive radiators have plastic   tanks (on

the

  >> ends of the core).  There ARE plastics that will survive  the  temps

and

  >> pressures...
  >>
  >>
  >> Matt-
  >>
  >> Yes but they are troublesome. It is automotive practice to use
  >> a 15 psi radiator cap but most rotary powered aircraft are   now using

30

  >> psi caps.
  >> I see no advantage in plastic over aluminium for aircraft use.
  >>
  >
  > My local BMW expert says for reliability purposes replace  the  plastic
  > radiators every two years.  I had two fail in a six year period.
  >
  > Hans
  >

Hans; the big thrill is when the tank on the heater core blows   apart as

you

are sitting there just idling in traffic. I have had that happen   with two
'beamers.' I don't know whether their plastic tank is worse than   anyone
else; but, I do still know that I have had to replace several of   their
radiators as well. Maybe Europeans just don't make as good a   plastic as

Matt

wants; but, while I joke about using pvc and/or glass almost   anywhere, off
the ground, in a pressurized situation in an engine compartment  is  just

not

going to be it, for me, anyway.
jofarr, soddy tn


Where did it break? The normal points are either the hose   connections or
the plastic lip that the
tabs bend over. These are the design fault points, BMW is  renowned  for
while making a quite
high tech car that goes really well when it is all working, they  also
make it so that it has a
rather high maintenance cost.

Don't like plastic fine
Then aluminium or steel (Just can;t see in)
Or another way is a thin sheet of perforated aluminium wrapped  around
the plastic tube.
as an additional pressure support.

The choice is still yours.

No matter which type of tube it is about the same effort to make.
Except for the aluminium wrap

Regards David Gaze

One method of finding the position of the piston inside a non  magnetic
cylinder is to fix a small magnet to the piston and use a   wristwatch compass
moved about on the outside of the cylinder. A ring of iron wire   around the
piston as well as the magnet may make it easier to find. On a plastic
cylinder a "stud finder" will sometimes work.

Colin Smith

Once the piston position is correlated to the pressure gage in the
cockpit, you will always know its location.  I am thinking of setting
up the floating piston to maintain coolant pressure at 20 psi and
using a 26psi cap on the swirl pot as a safety.  Opinions?   Jerry

Why plastic? Why not aluminum? You are asking for it with plastic.
Do you really want to fly around with a critical plastic part in your
airplane subject to 250 degrees F and 26 psi.
Plastic is cheap. That is its only advantage.

Paul Lamar

Paul,  I am not considering plastic.  It will be aluminum.  Jerry



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