The glass-sleeved Purolator has a filter area of about 1 3/4 sq in. The
larger and similarly styled K&N billet filter (and others like it) has an
area of about 4 in sq. The Flo-Ezy filter (advertised in Aircraft Spruce)
claims to have an area of 20 in sq (although by measurement I could only
make it to 10 sq in) and is available in a variety of mesh sizes.A
Gascolator is about 2 1/2sq in, although as Ron S points out its principal
is abit different.
Is the Purolator really a sensible size? especially on a fuel system with a
return-line.
I don`t think mesh size has much to do with it; if it were too coarse then
the rubbish would end up blocking something in the carbs. instead.
In a similar light, are we sure that the "air" getting into the fuel system
is not cavitation (as a consequence of large pumping capacity, fuel return
lines and various restrictions on the suction side (tank outlets, sharply
bent hoses, valves and filters)).
Duncan McFadyean
>Kevin Pownall wrote:
>>
>> I have spoken to three other builders [ two here in Australia ] who have
had
>> bad experiences with engine starvation. Not every one has had a forced
>> landing but they are 'Spooked' by this problem.
>>
>> The common thread is the puralator filter. They seem to be too fine and
to
>> have too small a surface area so that when even a little material comes
>> along they choke. Additionally the are prone to leak air [ possibly with
the
>> greater fuel pressure or the 914 pumps this is a new factor].
>
|