There is one more thing that needs cooling air, the muffler, there is a
lot of heat dumped into the cowl at the muffler. Cooling air needs to
be directed past the cylinders and then around the muffler to keep from
melting things under the cowl.
Regards,
Terry Seaver
A135 / N135TD
-----Original Message-----
From: owner-europa-list-server@matronics.com
[mailto:owner-europa-list-server@matronics.com] On Behalf Of Graham
Singleton
Sent: Monday, August 27, 2007 4:48 PM
Subject: Re: Europa-List: Broken Mag wire
Jeff
The thing to remember above all else is that ALL the cooling air should
go throught the radiators or the cylinder fins. Mainly the radiators.
(Not much heat comes through the cylinder walls, its all generated in
the head and the top of the pistons. So it heats the oil and the
coolant.) You should seal all the gaps round the radiators.
If you compare the area between the fins with the size of the gaps
around the rads, then consider the dragginess of the finning its not
surprising too much air leaks past and does no cooling at all.
Have a look at the cooling air inlet on this Long EZ, this efficiently
cools a 160 hp Lycosaurus and only needs about 8 square inches a side to
cool all four cylinders. The key is pressure recovery and good sealing.
High pressure to force the air through the fins and nowhere else.
The other pik is the first Europa fly in at rough river, October 06!
Wonderful weekend, except the Kentucky beer isn't much good, neither is
Kentucky wine. Kentucky bourbon is OK but they aren't aloud to sell it
to you!}}:-(
Graham
Sidsel & Svein Johnsen wrote:
<sidsel.svein@oslo.online.no>
>
> Jeff,
>
> I hope the fix you describe will solve the cooling issue.
>
> When I did the firewall-forward work, Andy Draper (at that time eith
EA2004) recommended that I closed the lower NACA - it should never have
been there for the 912/912S installations, he said, only for the 914's
turbo. As I recall our conversation, his point was that all this
additional air coming in at a place where it does not do any good for
912/912S, competes with the cooling air coming in through the cowl front
openings in getting out again. As air in = air out, I trust you have
already ensured that you have maximum possible outlet area aft/below,
without reducing the air flow through the coolers?
>
> Regards,
> Svein
> LN-SKJ
>
> Jeff wrote:
>
>> On my cooling issues it's just a mater of too high of pressure in
the lower cowl not letting the upper air from the top intakes down
through.
Sidsel & Svein Johnsen wrote:
> <sidsel.svein@oslo.online.no>
>
> Jeff,
>
> I hope the fix you describe will solve the cooling issue.
>
> When I did the firewall-forward work, Andy Draper (at that time eith
> EA2004) recommended that I closed the lower NACA - it should never
> have been there for the 912/912S installations, he said, only for the
> 914's turbo. As I recall our conversation, his point was that all
> this additional air coming in at a place where it does not do any good
> for 912/912S, competes with the cooling air coming in through the cowl
> front openings in getting out again. In other words, the more places
> you let air in, the less air actually comes in through each inlet when
> the outlet area is not increased. The NACA therefore effectively
> reduces the air flow through the cowl front, which is the air flow
> intended to cool the cylinders.
>
> Your fix should therefore improve things, I believe.
>
>> From what I can read between the lines, you don't have the Rotax
>> glassfibre
>
> cooling shroud over the cylinders and its (third) opening in the cowl
> front?
>
> As air in = air out, I trust you have already ensured that you have
> maximum possible outlet area aft/below, without reducing the air flow
> through the coolers?
>
> Regards,
> Svein
> LN-SKJ
>
> Jeff wrote:
>
>> On my cooling issues it's just a mater of too high of pressure in the
>> lower cowl not letting the upper air from the top intakes down
>> through. Until now the lower NACA was just shooting air into the
>> lower cowl with no direction causing the this high pressure. John
>> Hurst told me some time ago the demonstrator was set up this way and
it was fine.
>> This overheating never showed until this hot Tennessee heat wave hit.
>> Again I believe I'll have it solved. I have glassed in the lower NACA
>> to receive a 2 inch scat tube. This I will run to the upper part of
>> the cowl. I hope it eliminates the high, lower cowl pressure and
>> increases the top air pressure to force more air cooling down through
>> the cylinders. I should have it all fixed in time for next weekend's
>> fly-in at Rough River.
>
>
--
Graham Singleton
Tel: +441629820187
Mob: +447739582005
|