Ian

MGL 4 channel is a must I believe (although I have 2 gliders with KSA
CHT1DT and I add a switch arrangement with 4 channels and these instruments
are over 30 years old with transistors and still works!!!) How old is your
TV or phone.?

Consider the MGL as a one off insurance policy on the engine for about
$A550.  The bonus of always below 180deg c on climb is tappets NEVER NEED
TO BE ADJUSTED IN 700HRS!

Yes ASI between top and bottom is great way to go to check sealing of dam.
I have just learnt a falke has added a seal below the spinner and evened up
temps even more. He uses an MGL.

I am mostly down to 4deg C between cylinders but has taken a while.

Ian McPhee
0428847642
Box 657 Byron Bay NSW 2481



On Tue, 21 Jul. 2020, 08:52 Ian Williams, <[email protected]> wrote:

> Hi Rob
>
>
>
> Im not as technical as you, but if any help, when we were test flying the
> Grob 109 with the 2400 Stemme engine, we had to carry out a pre STC
> approval series of flight tests.  One was relating to engine and oil
> cooling.
>
> So we used a standard ASI with the pressure in the engine and the static
> behind the baffles.   We were comparing the indicated airspeed with the
> “baffle one”
>
> The results we got were as follows
>
>    1. Using the original baffles the ASI at slow speed was around  5Kts
>    faster   at higher speeds (100kts) the two came together
>    2. When we had finished the new baffles, we were getting a 15 Kt
>    difference at slow speed and again they came together at high speed.
>
> In practice it didn’t have a lot of effect on the CHT’s with the Grob.
> However a similar effort to make the baffles “as tight as a fish’s bum”  on
> our Dimona had a really big effect on the CHT’s.  We didn’t use the ASI
> test as were very happy with the results.
>
> I have recently installed a MGL 4 ch CHT (nice colours) which confirms our
> work.
>
>
>
> I hope that is some help Rob.
>
> Best regards
>
>
>
> Ian W
>
>
>
> *From:* [email protected] *On Behalf Of *Rob Thompson
> *Sent:* Monday, 20 July 2020 12:17 p.m.
> *To:* [email protected]
> *Subject:* [DOG mailing list] Cooling airflow and Mixture relationship
>
>
>
> G'day Everyone,
>
> As many of you will know I am OCD about sealing every tiny air leak in the
> Limbach engine bay compartment with silicone, aluminium tape and rubber
> cowl seals.
>
>
>
> I have previously rigged up a water manometer in the cockpit with the
> tubes running to the top and bottom of the engine. It told me I was getting
> very good pressure difference but I didn't take much notice of the actual
> measurements. I think it was somewhere around 30cm.
>
>
>
> As well as the ram air going into the front of the engine the lower cowl
> is designed to "suck". We fitted a big scoop type bottom cowl which seems
> to suck pretty well.... particularly with the baffles tightly sealed with
> silicon.
>
>
>
> What I am wondering now is..... What is the effect of this extra suction
> at the back of the engine on the carbs and mixture?
>
>
>
> Maybe it is not much different to flying at altitude and the SU carbs
> altitude compensating ability can deal with it.
>
>
>
> Any fluid dynamics physics experts in this Dog group who can enlighten me?
>
>
> regards
>
> Rob
>
>
>
> Rob Thompson
>
> 0429 493 828
>
>
>

Reply via email to