Morning Nigel. You are mostly right, but the first ones were stainless. The
n one =0Acracked on a factory aircraft (after take off at Sywell I remember
). Shortly =0Aafter that the =0A=0Afirst exhaust manufacturer changed to mi
ld steel without telling anyone. Next =0Aproblem was because of the very h
igh EGT the mild steel burned through and =0Aanother rash of failures devel
oped.Eventually their insurers got expensive and =0Anervous about anything
to do with aircraft. They stopped supplying exhausts and =0Aa new manufactu
rer had to be found in a hurry. Not easy!=0Aimho the problem with the early
stainless ones was that the stainless steel was =0Atoo thick, excess weigh
t, vibration loads and result, cracks. Some of we early =0Abuilders support
ed the heavy aft end of the box and had no problems.=0ATitanium would certa
inly fix it but the price might make one's eyes water.=0AGraham=0A=0A=0A=0A
=0A________________________________=0AFrom: Nigel Graham <nigel_graham@m-te
cque.co.uk>=0ATo: europa-list@matronics.com=0ASent: Wednesday, 11 May, 2011
9:18:59=0ASubject: Re: Europa-List: Carb, fuel and oil tube heat shielding
=0A=0ABack in the mid '90s, early adopters experimented with heat wrap and
claimed =0Areduced noise and marginal performance improvements (sub
jective). This was =0Afollowed by a rash of exhaust pipe fractures that
were attributed to the =0Aheat wrap and everybody dropped it like a, w
ell, hot exhaust. =0A=0AIt was subsequently discovered that the first batch
of (classic) exhausts =0Ahad been made out of mild steel and not the s
tainless steel specified, so it =0Ais possible that this could have bee
n a contributing factor.=0A=0AI have a motorcycle fitted with a titaniu
m exhaust. It is so thin that at =0Anight I can see the road ahead by
the cosy red glow. This system is =0Aincredibly light and ridiculously
resilient and I wonder if it would be a =0Asuitable material for a besp
oke Europa system - combined with heat wrap?=0A=0ANigel=0A=0AOn 11/05/2
011 08:42, Brian Davies wrote: =0A =0A>I have been following th
is thread and waiting to see if =0A>exhaust wrapping will be me
ntioned as a solution to high under-cowl =0A>temperatures. The
wrapping of exhaust systems has always been =0A>frowned upon i
n the certified world, supposedly because it causes =0A>crackin
g and corrosion of the system. Modern exhaust wrap is highly
=0A>effective and I am not aware of any negative effects. It i
s also =0A>approved by the LAA on a number of Rotax installatio
ns.=0A> =0A>My experience with it is on a closely cowled racing
engine =0A>where the heat reduction is quite dramatic.=0A> =0A
>Any comments?=0A> =0A>Regards=0A> =0A>Brian Davies
=0A> =0A>From:owner-europa-list-server@matronics.com =0A>[mailto:owner-euro
pa-list-server@matronics.com] On Behalf Of =0A>Sidsel & S
vein Johnsen=0A>Sent: 10 May 2011 21:39=0A>To: europa-list@matronics.com=0A
>Subject: Europa-List: Carb, fuel and oil tube heat shieldi
ng=0A> =0A>Ref. recent discussion regarding risk of fuel vapor
lock and how to =0A>shield the fuel system from engine heat.=0A
> =0A>Attached is photo and sketch of the carb heat shields I m
ade out of =0A>s/s steel plate. Fixed to the exhaust pipes by
s/s hose clamps. =0A>The clamps expand and contract in approxi
mate sync with the exhaust =0A>pipes, so no cracking discovered
and no re-tightening required. As =0A>will be seen, the carbs
have heating blocks installed, which (as =0A>stated by Graham)
makes the factory heat shields difficult to use.=0A> =0A>All fuel hoses fo
rward of firewall are protected by both fire sleeve =0A>and hea
t sleeve (claimed to reflect approx. 90% of radiated heat)
=93 =0A>see photo. Both purchased from racing car supply sh
op in the UK =0A>(don=99t recall name, and I am
away from my file). I also =0A>use the heat sleeve on oil lines
running very close to the engine.=0A> =0A>/////=0A> =0A>Regarding the
fuel return restrictor: I use the restrictor supplied =0A>by t
he factory in 2001. Do not know the hole diameter, but it is
=0A>less than 0.5 mm. The opening is indeed surprisingly small,
but =0A>bear in mind that gasoline has very low viscosity
compared to e.g. =0A>water. =0A>=0A> =0A>(I sent an ea
rlier message today with same heading, but it =0A>appears it di
d not go through. If it does pop up, pls disregard it)=0A> =0A
========================
=0A
|