While delving into the various Rotax manuals in pursuit of information about the
fuel manifold, I noted the dimensions of the restrictor in the fuel return line
- 0.35mm ID.
I have been considering the most elegant way to incorporate the restrictor
supplied
by Europa (FS02) into my home-brewed alternative to the Rotax manifold and
so checked its dimensions. I find that the restrictor hole will easily pass
a number 71 drill bit, but barely accepts the shank of a number 70 drill bit.
So I deduce that the orifice is about 0.7mm ID, ie twice the diameter of the
Rotax
one.
Why should Europa have supplied a different size of restrictor from that called
out by Rotax?
Looks as though the Rotax orifice will (in any otherwise identical circumstance)
allow the fuel pressure to build up slightly higher, and return less fuel to
the tank, than the Europa one. It might just make the difference between pass
and fail in a fuel flow test.
Has anyone had any issues traceable to this difference between the
Europa-supplied
restrictor and the Rotax one?
I might consider machining up my own manifold (obviously I'm heading into deep
water with LAA engineering here) and if so, which size of orifice should I
incorporate?
Should it be removable, rather than integral, to allow fine-tuning of
fuel pressure?
in friendship
Rowland
| Rowland Carson ... that's Rowland with a 'w' ...
| <rowlandcarson@gmail.com> http://www.rowlandcarson.org.uk
| Skype, Twitter: rowland_carson Facebook: Rowland Carson
| pictures: http://picasaweb.google.com/rowlandcarson
|