Lyndons Savannah VG Thread

[Lyndon]

Is this in relation to carby heat. I understand tge oat but not the airbox.

 

 

[Kyle Communications]

carby icing is a need to know...this is why you need the airbox temp

 

 

[Lyndon]

Is there a formula using this air box temp. Been a long time since i flown but have never come across it.

 

Lyndon

 

 

[fallowdeer]

Hi Lyndon

 

In conditions conducive to carburettor icing my suggestion would be to use the alternate warm air supply to maintain 20-24 degrees air box temperature.

 

This is in line with the ICP Savannah VG flight manual. (Available online, Google it)

 

Compared with traditional carburettor heat systems on Lycoming and Continental engines there appears to be less of a performance loss when using alternate air. For this reason in the wintertime I put a small (about 5mm) sleeve around the control wire between the knob and panel, thus keeping a partial supply of warm air at all times. This results in the air box temperature mostly staying in the range I want.

 

As an aside a very experienced commercial helicopter pilot I know used to, when operating a R44 with carbureted engine, always flew with a trickle of carb heat on except when he needed maximum power.

 

Peter

 

 

[Lyndon]

Makes sense. Will chase up the manual

 

Lyndon

 

 

[IBob]

So, would it be right to say that the outside air temperature is a (partial) guide to when you are in a possible carb icing situation....and the airbox temperature probe allows adjustment of the alternate air (knob) to maintain something like the desired air temperature into the carbs???

 

 

[fallowdeer]

Yep, OAT and dew point are what I keep an eye on when considering carb icing. And of course OAT necessary for density altitude calculations.

 

Peter

 

 

[Lyndon]

I'm fitting my oat gauge at the moment. Its a vdo plastic unit. Two long bolts slide in the body then two brackets mount on each side. Its not at all correct and they just splay. Has anyone come across this before.

 

Lyndon

 

 

[facthunter]

Ibob, I think carb(throttle body) temperature is a good guide to icing If your airbox gets warm air from the engine all the time, you are losing potential power. Anti or de icing (Which are a little different in function) should cause a certain minimum rise in temp in a given time as a measure of effectiveness. In a long descent with throttle closed your engine sources of heat diminish. Ineffective de icing can make the situation worse (sometimes) Each individual situation would vary. A certain minimum throttle body temp may prove to be adequate as a guide and less than that not successful. Warmer Maritime air has the most water content and inland where there has been extensive rain over a period of time. Low cloud and fog in valleys is an indicator but clear air is nor a guarantee of no problem where the temp drops a lot in the fuel mixture system. (evaporation throttling) nev

 

 

[rankamateur]

I'm fitting my oat gauge at the moment. Its a vdo plastic unit. Two long bolts slide in the body then two brackets mount on each side. Its not at all correct and they just splay. Has anyone come across this before.Lyndon

Yes!

 

 

[dan tonner]

I'm fitting my oat gauge at the moment. Its a vdo plastic unit. Two long bolts slide in the body then two brackets mount on each side. Its not at all correct and they just splay. Has anyone come across this before.Lyndon

Hello Lyndon;

I've been following your build with interest for some time - takes me back to my trials and tribulations of building my VGXL in 2012 - 2013.

 

With regards to the plastic instruments: my kit came with the plastic VDO gauges for both Temperature and RPM. VDO make spin-on mounting collars for these plastic gauges and they are relatively cheap to buy and solve the "spindly-legs" problem and the risk of cracking the gauge body by over tightening.

 

The gauge bodies are already threaded toaccept the spin-on collars VDO was easy to deals with and shipping was prompt.

 

All the best, fly safely;

 

Canada Dan

 

 

[Lyndon]

I fixed it with two cable ties wrapped around the body. Its light and a tight fit anyway. These just lock it in.

 

Lyndon

 

 

[Lyndon]

Gauge readings.

 

I'm wanting to put some thin tape on where I can expect

 

Oil pressure

 

Head temps

 

Oil temp

 

Fuel pressure

 

Oil temp

 

What are normal readings for a Savannah vg in your experience.

 

Lyndon

 

 

[Lyndon]

Cables. I'm interested in knowing if the choke. Heater. Air box heater cables benefit from grease or lube or best kept dry. ???

 

Lyndon

 

 

[Lyndon]

I read the user manual with interest. It says wire the fuel tap on but with small enough wire that it can be overridden by breaking it to turn the tap off.

 

Lyndon

 

 

[rankamateur]

I read the user manual with interest. It says wire the fuel tap on but with small enough wire that it can be overridden by breaking it to turn the tap off.Lyndon

Haven't seen it done anywhere I have been.

 

 

[Lyndon]

I have just noticed my front wheel leg will come close to my throttle linkage. In fact it looks it will hit. Unless I pull it apart to check. Can some one look at their plane to confirm if this correct. I can't see how it can be done incorrectly. But ???

 

Thanks Lyndon.

 

 

 

[Lyndon]

Progress. After a long break.

 

Lyndon

 

 

 

[skyfox1]

Hi Lyndon I had similar situation on my 701 very close to the linkage so I removed mine and put in a vernier style throttle , cables eliminates all the linkages just have two cables to carbys

 

 

[Lyndon]

It does look like it won't clear. From what see the leg has about 3 plus inches of travel.

 

Lyndon

 

 

[Lyndon]

Do you have some info on your throttle cables ??

 

 

[skyfox1]

 

 

 

[Lyndon]

Great. I will have a close look at it. They work with dual throttles ??? Lyndon

 

 

[skyfox1]

Yes they work with dual throttles so long as you get the right one so passenger side isn't locked ,gets rid of all that linkage system mine works great

 

 

[Lyndon]

With dual throttles.where does it double up. At the carbs ????.

 

Lyndon