Graham, In my innocence I thought that the plane was
designed so that in normal cruise attitude the engine axis
was horizontal and the blades at equal AOA
Regards, David Joyce, G-XSDJ
GRAHAM SINGLETON <grahamsingleton@btinternet.com> wrote:
> Karl
> 3 blades will always be smoother because when the 2
>blades are horizontal each blade sees a
> differentAoA,especiallywith high angles of attack.
>This causes different thrist on the blades resulting
> in yawing oscillation of the airplane.
> Graham
>
>
> ________________________________
> From: Karl Heindl <kheindl@msn.com>
> To: europa-list@matronics.com
> Sent: Tuesday, 26 June 2012, 14:57
> Subject: RE: Europa-List: Re: Contact detail & Help
>
>
>
> Hi Frans,
>
> Thank you for the additional information. I will follow
>your advice, but probably not until next year.
> If you are going to publish in the flyer, then some good
>pictures please of the radiator installations.
> Also, a source for the rads.
>
> You mentioned that the prop is not as smooth at lower
>rpm's. I have the same prop and I discovered a long time
>ago that the carbs need to be in sync 100% for a
>two-bladed prop. With three blades the carbs would need
>to be out of sync quite a bit before you would notice. I
>know, because I tried it by putting my original Warp
>Drive back on.
>
> Karl
>
>
>
>
>
>
>
>> Date: Mon, 25 Jun 2012 23:09:34 +0200
>> From: frans@privatepilots.nl
>> To: europa-list@matronics.com
>> Subject: Re: Europa-List: Re: Contact detail & Help
>>
>> Hi Karl,
>>
>> > I have been following your developments with great
>>interest and I think
>> > that the end result is just plain amazing.
>>
>> Thanks!
>>
>> > Now, top speed is very useful for testing drag
>>improvements, but you
>> > don't cruise at those speeds, do you ? When you are
>>touring, what are
>> > your preferred settings regarding speed, MP, rpm etc.,
>>and exactly what
>> > is your fuel consumption then.
>>
>> I found the sweet spot of the aircraft is with 27 inch
>>MAP, where it
>> usually cruises with a speed somewhere between 120 and
>>130 KIAS,
>> depending on C of G and some other obscure factors. Fuel
>>consumption
>> used to be 16 to 17 liters per hour, but I have observed
>>this year that
>> the fuel consumption has increased to 18 liters per
>>hour. Maybe the
>> carbs need an overhaul or so.
>> RPM is usually between 4800 and 5000 RPM, this feels
>>best for the
>> engine. I have a two blade prop and at lower RPM's it
>>feels less smooth.
>> Of course actual settings depend on various
>>circumstances. With a strong
>> head wind we usually advance the throttle a bit, with a
>>tail wind we
>> enjoy the lower fuel consumption of a lower power
>>setting. We fly 90% of
>> our cruising with power between 26 and 28 inch.
>> With higher power settings the fuel consumption goes up
>>faster than the
>> gain in speed. Other than in a car, a higher speed
>>doesn't give any
>> other feeling than a lower speed, it just gives the same
>>sensation. One
>> hour flying is still one hour flying. On a 3-hour trip I
>>rather enjoy an
>> additional 10 minutes flying and have a free meal than
>>just cranking up
>> the fuel consumption, paying more for less fun. AVGAS
>>can be close to 3
>> Euro's per liter over here, so saving 10 liters on a
>>trip can save
>> enough money to have a dinner for two! ;-) I love
>>telling friends that
>> flying there isn't more expensive than getting there by
>>car.
>>
>> > If the rest of us mortals wanted to implement some of
>>your changes
>> > without too much expense, what would you recommend ?
>>
>> There isn't much money involved actually. The radiator
>>costs about 300
>> Euro's, the heat exchanger a bit less. You can do
>>without the heat
>> exchanger, I have been flying one summer with the stock
>>oil radiator fed
>> by a 2" Scat tube via a wedge diffuser. Apart from the
>>long warm up time
>> it was quite an improvement over the tandem setup. Best
>>thing to do is
>> to scrap the stock coolant radiator, dog house, duct and
>>associated
>> hardware and just install a thin radiator in a 45 degree
>>angle in front
>> of the exhaust and turbo.
>>
>> The main hurdle here is to shape a new underside of the
>>cowling. You
>> have to be brave enough to cut the dog house away, and
>>then insert a
>> block of blue foam and start cutting, rasping, sanding
>>until you have
>> the shape you desire. Anyone who wants to make a mold
>>out of my cowling
>> is welcome to do so, provided I'm allowed to use that
>>mold to make a new
>> light weight carbon cowling for myself. ;-)
>>
>> BTW I'm not the only one who devised something like
>>this. See the
>> attached picture. This is another configuration with a
>>thin radiator in
>> a 45 degree angle, although it lacks a cowl flap and
>>heat exchanger for
>> the oil. (Oil is cooled by a radiator, fed by a NASA
>>duct on the port
>> side, you can see it on the picture). Also this owner
>>claims very good
>> results with his setup on his 914 engine. The key really
>>is to use a
>> thin radiator and mount it at the belly so the "used"
>>air can take the
>> heat of the exhaust with it, and enjoy the benefits of a
>>very sleek
>> cowlng, excellent cooling, low pressure losses, and
>>minimal cooling drag.
>>
>> Anyway, my cooling design is not an exclusive invention
>>of me but the
>> combination of ideas and experiments of multiple Europa
>>owners who
>> believed that the cooling of the Europa could be
>>improved other than by
>> using draggy brute force solutions.
>>
>> > What is the part number for the
>> > heat exchanger and exactly where did you install it ?
>>
>> See picture, taken from under the engine. The heat
>>exchanger is mounted
>> behind the engine. This was the first setup, with the
>>stock coolant
>> radiator, hence the configuration of the coolant hoses
>>pointing
>> downwards. In the current design the hose routing has
>>been changed to
>> accomodate for the thin belly radiator.
>> If you really want to go this way, contact me privately
>>for more info.
>> One caveat though: this heat exchanger has very thin
>>canals and is not
>> compatible with Evans coolant due to its viscosity. I
>>use it with 50/50
>> without problems.
>>
>> > It also had a very
>> > small (8AH?) battery.
>>
>> I also have a small 8Ah battery, never needed anything
>>more than that.
>> But I have a second alternator (mounted on the vaccuum
>>pad) so I don't
>> need the battery as a backup during flig=====
|