Wren 80

[Chris Channon]

Hi all, I wonder if you could help. I have a Wren 80 I really nice engine and I have been running it on the recommended paraffin / two stroke oil. My problem is that if I leave the engine for a few weeks before running I get a couple of false starts because the engine turns over slowly because of the oil residue I think. After a couple of attempts it starts and runs fine, my question is .. if I change oil to Mobil turbine oil can I just run the engine on the new fuel / oil or will I need to flush out the old 2 stroke mix with something then run the new paraffin/Mobil mix ? Thank you in advance, Chris C

[simon burch]

Chris,

Why have you been using two stroke oil. Who recommended that to you?

Hopefully you've not damaged anything but I'm not sure if two stroke oil has the properties to fully lubricate a turbine. Might be worth giving Wren Power systems a ring to check that the oil has not potentially burnt inside the engine and blocked anything.

If it feels smooth and the burner lights evenly from the rear (nothing blocked), then I'd just run a tank through will the correct turbine oil and you should be good to go. Don't skimp on the oil, they get very expensive if something fails.

I have a Wren 80 myself, great little turbines.

Simon

[Chris Channon]

Hi Simon, thank you for the reply. I will start using Mobil oil at the weekend and see how that goes.

I use 2 stroke oil as this is my first turbine and followed the manual and it says that " Wren recommend a good 2 stroke oil - they use a supermarket brand as it is easy to obtain and is cheap" !

Again, thank you Simon hopefully using Mobil oil will stop the poor starting issues after a longish lay up.

Regards

Chris C

[Harry Curzon]

Best thing to do is to ask Wren as they will know the answer! In the meantime, the red two stroke Carlube oil that Wren suggests should be fine, mine run on it and don't fail to start immediately after as much as an 8 month break while I fly other jets. What failure message is the data terminal giving when the start fails? Could it be a tired or cold lipo that isn't delivering until it has warmed up a bit as current is being drawn from it? Gas or kero start?

Edited By Harry Curzon on 22/03/2016 11:08:02

[stevejet66]

Not sure why your getting false starts, The fadec will be programmed to give a pre start prime to both the oil feed/bearings and injectors, More than enough lube for starting, Start fail can also be through having your throttle trim to low, Take it up two pips.

[Paul De Tourtoulon]

I get really slow first starts on the day, posted in the Wren 54 post,,,,

[Paul De Tourtoulon]

Here it is,

 

Another flame out, this time with my Jubilee on take off, a good job I fitted brakes, a re start and off it went, it's very slow on start up especially the first in the day when cold, I will do a video and post it if anyone out their can tell me what I need to reprogram for quicker starts.

 

 Reading my old Wren 54 instructions I did modify the Pump start point from 026 to 030 as new it would not start, I will shove my Pump start ramp from 004 to 005 or 006

and maybe Preheat fuel later from   035 to 040, although it is the south of france rarely under 20°c,,

what do you think ?.