I have been following this thread and waiting to see if exhaust wrapping
will be mentioned as a solution to high under-cowl temperatures. The
wrapping of exhaust systems has always been frowned upon in the certified
world, supposedly because it causes cracking and corrosion of the system.
Modern exhaust wrap is highly effective and I am not aware of any negative
effects. It is also approved by the LAA on a number of Rotax installations.
My experience with it is on a closely cowled racing engine where the heat
reduction is quite dramatic.
Any comments?
Regards
Brian Davies
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Sidsel & Svein
Johnsen
Sent: 10 May 2011 21:39
Subject: Europa-List: Carb, fuel and oil tube heat shielding
Ref. recent discussion regarding risk of fuel vapor lock and how to shield
the fuel system from engine heat.
Attached is photo and sketch of the carb heat shields I made out of s/s
steel plate. Fixed to the exhaust pipes by s/s hose clamps. The clamps
expand and contract in approximate sync with the exhaust pipes, so no
cracking discovered and no re-tightening required. As will be seen, the
carbs have heating blocks installed, which (as stated by Graham) makes the
factory heat shields difficult to use.
All fuel hoses forward of firewall are protected by both fire sleeve and
heat sleeve (claimed to reflect approx. 90% of radiated heat) - see photo.
Both purchased from racing car supply shop in the UK (don't recall name, and
I am away from my file). I also use the heat sleeve on oil lines running
very close to the engine.
/////
Regarding the fuel return restrictor: I use the restrictor supplied by the
factory in 2001. Do not know the hole diameter, but it is less than 0.5 mm.
The opening is indeed surprisingly small, but bear in mind that gasoline has
very low viscosity compared to e.g. water.
(I sent an earlier message today with same heading, but it appears it did
not go through. If it does pop up, pls disregard it)
Regards
Svein
LN-SKJ
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