Hey bob,
Glad to hear you r home. How was
The trip? Did u miss the Europa?
Reg
TR
On 10/07/2010, at 6:08 PM, "JR Gowing" <jrgowing@bigpond.net.au> wrote:
>
> Frans
>
> Just back from holiday in US and seen your list of problems.
>
> Have you seen the Tropical Chin Intake?
>
> I have just fitted one to my 912S installation, still a long way from flying.
>
> It forms a sharp edged entry to the large rectangular inlet with a much
> smaller
eliptical entry formed from aluminium.
> I think I downloaded it from the Europa Club but Popular Flying Assn mentioned
at the top of page 1.
>
> Frustration is a killer!
> Best Wishes
> JR Gowing Kit 327 in Oz
>
> ----- Original Message ----- From: "JEFF ROBERTS" <Jeff@rmmm.net>
> To: <europa-list@matronics.com>
> Sent: Sunday, June 06, 2010 3:52 AM
> Subject: Re: Europa-List: Cooling issues, once again!
>
>
>>
>> Frans,
>> I have the 912 set up so I might not know what I'l talking about but...
>> I had the very same issues for the first 150 hours. Every time it got
>> hot I was in trouble with temps at their limit. I made the shroud for
>> over the cylinders. I lowered the oil radiator 2 inches behind the
>> water, I sealed everything, I made new inlets in the upper cowl, and
>> still didn't get it solved completely. I then finally lowered the
>> metal duct down an inch or so, so the bottom radiator reached the
>> lower cowl without the sealant and bam. My temps dropped 30 to 40
>> degrees. I believe two things helped in this. The radiators we're
>> getting more air but the big thing was by lowering the duct it opened
>> the bottom for escaping air. Not sure if this all applies to you but
>> if you have the duct up to high close to the muff all you need to do
>> is lower it. You'l be needing to ad a flap in colder days to get
>> things in the proper temp range.
>> By the way the shroud did even the cylinder temps out but it didn't do
>> much to cool the water or oil.
>>
>> Jeff R. N128LJ Gold Rush
>>
>>
>>
>>
>> On Jun 5, 2010, at 5:28 AM, Frans Veldman wrote:
>>
>>> >
>>>
>>> Gentlemen,
>>>
>>> Although my initial cooling issues have been improved upon, I'm not
>>> satisfied at all with the cooling of my 914.
>>>
>>> Now, with increasing ambient temperatures, I have to severely limit my
>>> climb outs. Cruising is ok. During climb, both the water temperature
>>> and
>>> oil temperature approach the red line, more or less at the same time.
>>> Water temperature recovers faster than the oil temperature after I
>>> power
>>> down. At this time I can barely make it to circuit height and then
>>> have
>>> to level off, build more speed, and then limit my climb with 200 ft/
>>> min
>>> until I'm in cooler air. The engine has now 32 hours on it, so it
>>> might
>>> still improve somewhat further, but I don't expect miracles from that.
>>>
>>> I had to do something.
>>> First I made an additional exit in the cowling, under the turbo,
>>> hoping
>>> to provide more airflow. Whether the airflow in the cowling improved I
>>> don't know, but it had zero effect on the water and oil temperatures.
>>>
>>> Temperatures inside the cowling seem to be ok anyway, no discoloured
>>> spark plug indicator labels (still bright yellow), no melted tie-
>>> wraps, etc.
>>>
>>> My conclusion was that the problem is not in cooling of the cowling,
>>> but
>>> somewhere in the efficiency of the radiators.
>>>
>>> So then I built a new radiator inlet, somewhat larger than previous
>>> one,
>>> with a lip to avoid digesting the boundary layer and making sure the
>>> inlet receives ram air, angled straight into the airflow, and with a
>>> diffuser for which I copied a profile out of a famous book.
>>>
>>> It was no improvement over my "free style" sleeker inlet and diffuser.
>>> None. Very frustrating, as I ruined my nicely shaped and painted
>>> original inlet for this.
>>>
>>> I need to do something, but to avoid ruining again something in
>>> order to
>>> solve this problem, I need to hear some experiences:
>>>
>>> 1) A shroud over the cylinders. I don't have it, but instead I have
>>> two
>>> naca ducts in the upper cowling, curved down to release air aimed at
>>> the
>>> cylinders.
>>> Has anyone ever tried whether the Rotax shroud (or home made shroud)
>>> makes any difference? Sure, it will cool the cylinders, but does it
>>> have
>>> any effect over the water temperature and/or oil temperature? Or is
>>> this
>>> again going to be a loss in time and effort?
>>>
>>> 2) In my setup the oil cooler receives exit air from the water
>>> cooler. I
>>> know there is a "trick" mentioned in the build manual for hot climates
>>> to lower the oil radiator 2 inches to receive cold air instead of warm
>>> air, but I didn't opt for this as I don't consider our climate as
>>> extremely warm, and in winter the oild could actually get too cold.
>>> Has anyone tried both options, and did it make much difference? Also,
>>> did it have any influence over the water temperature? Relocating the
>>> oil
>>> radiator will be a large project, and I fear that after that I will
>>> still have to limit my climb outs to avoid the water from boiling.
>>>
>>> Yesterday on the airfield I took a closer look at the Rotax 914
>>> equipped
>>> Dimona, which is used by the glider club to tow all day long gliders,
>>> with full power at 50 knots, in all ambient temperatures. They never
>>> have cooling problems.
>>>
>>> What I saw was shocking. The water radiator is fully exposed to the
>>> airstream, no diffuser whatsoever, it is just part of the cowling,
>>> as if
>>> someone took out some skin of the cowling and fitted the radiator in
>>> the
>>> resulting hole. The oil radiator is mounted in an angle behind a naca
>>> duct (I was taught that a naca duct does not provide ram air and
>>> shouldn't be used for cooling a radiator?). Both radiators just dump
>>> the
>>> warm air inside the cowling! It can't be easier than that.
>>> Then, at the bottom, the Dimona has a cowl flap which just opens the
>>> cowling to dump *all* air overboard. If it is closed, all radiators,
>>> as
>>> well as all cowling ventilation, is blocked.
>>> How can this system, which looks less sophisticated than our system,
>>> while violating all rules and knowledge, work so well?
>>>
>>> Anyway. At the moment I'm grounded, can't fly like this, and after
>>> spending a week trying to improve things with zero effect, I'm out of
>>> options and I'm inclined to leave the airplane in the hangar and find
>>> another hobby. :-(
>>>
>>> Seriously, what should I do?
>>>
>>> Frans
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>>
>
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