Nigel=0Aanother problem with those filters is that sometimes they look clea
n but aren't because the contamination is translucent when wet with fuel; s
o, more restriction.-=0AYou're right, they are too small. quite high fuel
flow with a 914.=0AGraham=0A=0A=0A=0A________________________________=0A F
rom: "nigel_graham@m-tecque.co.uk" <nigel_graham@m-tecque.co.uk>=0ATo: euro
pa-list@matronics.com =0ASent: Monday, 29 October 2012, 10:01=0ASubject: Re
: Europa-List: Vapour lock? Why?=0A =0A=0A=0A=0AOn 31/07/2012 22:27, klinef
elter.kevin@gmail.com Snip .........I was chatting with Rob Seaton ( of Rot
ech in canada). He said he learned how too small a fuel line and/or torture
d routing can cause "cavitation" at the pumps. So maybe your fuel filter(s)
, on the suction side of the pump,are causing cavitation in the pump(s). Ma
ybe due to the size (restriction of flow) of the filter, even if they are c
lean.=0A........Snip=0A=0AKevin, I think Rob Seaton may be on the money wit
h this one.- =0AA year or so back, I experienced a dead cut while flying
a friend's=0A 914 powered Europa on a hot day. Nifty application of fuel
pump=0A restored the noise, but once safely back on the ground, I check
ed=0A the filters (all clean). This aircraft was fitted with Europa=0A
specified Purolator glass shrouded filters that allow you to see the=0A
fuel flowing. At low RPM, the filter appeared full, but as power was=0A
increased, the filter began to fill with what I thought was air. My=0A
first action was to check the pipework and security of connections -=0A
but everything seemed fine - it was definitely not drawing in air=0A fr
om anywhere. I then concluded that I had experienced vapour lock=0A and
left it at that.=0A=0ACuriosity got the better of me and I started research
ing cavitation=0A and stumbled upon this very stilted, but interesting p
resentation on=0A Youtube. Take a look at the first minute from 00.20 -
in particular,=0A the glass venturi. This was exactly what I saw in the
Purolator=0A filters.=0A=0Ahttp://www.youtube.com/watch?v=K_w3gcvA87I
=0A=0AMy conclusion is that the Purolator filter has the correct mesh size
=0A to trap contaminants, but the filter capacity is too small and=0A
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