Fred, One thing I should have mentioned is that I have the
Singleton firewall mod, which replaces the stainless steel
with a thickish heat resistant fibreglass. That is of
course a whole lot less likely to traumatise a rubber hose
than stainless steel, but if I had the stainless steel
original firewall I would still be tempted to try to make
holes with a turned smooth edge or to get a large grommet
so as to still avoid extra connectors. But that is all
largely irrelevant, I guess with your fuel injected, high
pressure system!
Regards, David Joyce, G-XSDJ
Fred Klein <fklein@orcasonline.com> wrote:
>
> On Mar 21, 2014, at 10:43 AM, David Joyce
><davidjoyce@doctors.org.uk> wrote:
>
>> Any sort of fitting adds weight and leakage possibility.
>>Going straight through the firewall with the hoses
>>immobilised on both sides, with the passage sealed by
>>silicone adds nil weight ,no leakage possibility and
>>works in the sense that having already replaced hoses
>>twice on a five year life basis, the pipes showed no sign
>>of chafing wear. Why complicate things?
>
> David,
>
> Thanks for the description of your installation as well
>as your report of trouble-free operation over a ten year
>periodyours is simplicity itself, and I salute you for
>it while I also admit to envy of your accumulating all
>the hours of airtime which you have while my kit remains
>in my workshop.
>
>>> Why complicate things?
>
> I suspect that one persons complication may be
>anothers sense of proper kit, both being subjective
>assessments for dealing w/ the task at hand, whatever it
>may beand...a reflection of ones comfort zone.
>
> In my case, I recall a sense of discomfort at the
>thought of simply running a rubber hose w/ fuel under
>high pressure through the firewallI was also keen on
>matching the FWF SS jacketed fuel line which my engine
>supplier had already used connecting the injector
>railsthe firewall seemed like the logical place for the
>transition, and the weight of the aluminum fittings was
>not a detriment for me.
>
> As my fuel lines are under high pressure for a
>fuel-injected engine with the pumps located aft, I paid
>little attention to the build manual references to
>routing of the low pressure fuel lines for the Rotax
>engine, relying instead on an old dog-eared copy of an
>EAA publication, Firewall Forward by Tony Bingelis.
>
> What Ive done made perfect sense to me at the time the
>work was being done
>
> Cheers,
>
>Fred
>
>
|