Jodel 120 Performance!?

[WBerry]

Hi All,
I haven't posted here in years, I hope you're all well

To business, I wonder if you might shed some light on my aircraft performance.

I've just bought a very nice Jodel 120 (G-BJYK) with an 0-200 engine and an EVRA prop, but I'm not convinced its performance figures are as good as they should be.

If I typically cruise at 2350-2400 RPM I get 85-90knts, and flat out I'll get 100-105knts at 5000rpm. But in my typical cruise I think I'm seeing fuel consumption of 23-24 lts/hr. Is that reasonable?

Then there's the climb, which fully loaded is 500-600fpm. Again, is that fair enough when fully loaded?

I've tried leaning her off at altitude but only get maybe a 20rpm improvement. And applying Carb Heat has the expected drop in revs. So I'm thinking it's not running that rich or having any issue with a blocked air filter.

The EVRA prop is the regular one used in many similar aircraft. Engine compressions range from 74-78 at last measuring (which I believe is very good).

So what do you reckon? Is it just my expectations that are off

All help appreciated.

Will.

[Brian Hope]

Hi Will, your figures do seem a bit low on speed and high on consumption. My 117 gives 95kts at 2350 on 21 lph. A friend, with whom I have often flown, has a 120 and he goes away from me, only by a couple of knots or so, and he has a C90 and uses 21 lph.
Assuming your ASI is reading correctly, are you getting the aircraft 'on the step'? If not you are not getting the best out of it. When you set up for cruise, allow the speed to increase and ease back to cruise rpm. Then give the stick a suggestion of nose down and let the speed ease up a little, the aircraft will find its sweet spot and retain the increased speed without losing height as you take the suggestion off the stick. It's a matter of feel really, which takes a bit of practice.
Regarding consumption, I don't know too much about the O-200 other than it seems to me that it revs its nuts off compared to a C90 for little benefit.
I was chatting to a Jodel owner the other day who has fitted a Hercules prop and he was getting very good results, 105kts cruise at 2350 I believe and still keeping good take-off and climb performance..
The Evra is a very good prop though but does come in climb and cruise variations, off the top of my head I don't know which is which, though technically both are 'regular' fits for the 120.
You have chosen wisely, the D11 series are great aeroplanes which will give you an awful lot of affordable fun. If you're not on the Yahoo Jodel Group forum then I suggest you join, plenty of pearls on there, fortunately mixed with very little grit.
Best rgds, Brian

[WBerry]

Thanks Brian,
It is a lovely machine. And I'll get on that Forum.

[Nick Allen]

100-105knts at 5000rpm

5000rpm sounds awfully fast to me...do they really spin that much?

[Ian Melville]

Me thinks it will sound like a Harvard at that RPM, me thinks typo.

[phil brookman]

Hi Will, your figures do seem a bit low on speed and high on consumption. My 117 gives 95kts at 2350 on 21 lph. A friend, with whom I have often flown, has a 120 and he goes away from me, only by a couple of knots or so, and he has a C90 and uses 21 lph.
Assuming your ASI is reading correctly, are you getting the aircraft 'on the step'? If not you are not getting the best out of it. When you set up for cruise, allow the speed to increase and ease back to cruise rpm. Then give the stick a suggestion of nose down and let the speed ease up a little, the aircraft will find its sweet spot and retain the increased speed without losing height as you take the suggestion off the stick. It's a matter of feel really, which takes a bit of practice.
Regarding consumption, I don't know too much about the O-200 other than it seems to me that it revs its nuts off compared to a C90 for little benefit.
I was chatting to a Jodel owner the other day who has fitted a Hercules prop and he was getting very good results, 105kts cruise at 2350 I believe and still keeping good take-off and climb performance..
The Evra is a very good prop though but does come in climb and cruise variations, off the top of my head I don't know which is which, though technically both are 'regular' fits for the 120.
You have chosen wisely, the D11 series are great aeroplanes which will give you an awful lot of affordable fun. If you're not on the Yahoo Jodel Group forum then I suggest you join, plenty of pearls on there, fortunately mixed with very little grit.
Best rgds, Brian

who is this man with the herculess what engine is he running very interested as i have an evra

[Brian Hope]

Hi Phil, it is Alan Kilbride, who does post on the forum now and again so may well respond. He has C90 in his Jodel.
Best rgds, Brian

[Alan Kilbride]

Ok, I am going to put my unofficial figures on here. At the risk of being derided on the basis that you don't get something for nothing.

The propeller is a Hercules 68" X 56".
Max S & l is 2500rpm--------------123kts. With the Evra it would rev to 2675 and 117kts
At 2250--------------105kts
At 2350 max auw-------------110kts+..............solo 115kts

I lose approx 50fpm in the climb and a negligible amount on the t/o.
Leaning out at 2250rpm I burn around 19-20 litres an hour. With the Evra I was burning 18 litres at 2350 and 95 kts.

After getting really Pi$$ed off with so called experts telling everyone who would listen that my figures are impossible, even when backed up with independent verification, I have taken one such individual on a flight to prove it and he spouted forth with his vast knowledge that there must be something wrong with the ASI and the GPS is being affected by the wind. This is the same aircraft with the same ASI as when the Evra prop was fitted and even though we flew on all four cardinal direction to balance the GPS speed, still denied the results.
If anyone sees me around the Country and wants a quick trip, I would be happy to oblige. I am based at Full Sutton EGNU near York if you are near too.
I believe the prop is now on the PTL list at the LAA too.
Sorry for sounding off, but take a look at the Jodel forum for a sample of one such person.

Alan
.
Still happy and daft as a brush.

[phil brookman]

just pm ed u
but to continue with this interesting thread .
have u 4 way clocked ur asi with gps by any chance ..
love ur so called expert lol they get every where lol
which evra did u have
hope to give u my figs with a 65 shortly
best

[phil brookman]

must watchout for this gps affected by wind effect lol.....

[Alan Kilbride]

It was the Evra D11 28 1b which was the only Evra on the Jodel C90 list Phil.
I have crossed my teeth, gnashed my eyes, hopped on one ear, burnt slivers of fog, prayed to the Great God Buster Keaton and even threw a penny into the River Ouse.
Still the Speeds are the same as those posted on video 9 months ago on first flight test and last Saturday as an unedited 12 plus minutes.
I have also flown alonside 2 other D117s and my numbers add up.
Obviously it is greedier by the hour on fuel, but at 2250 rpm and 105kts I suggest it can be more fuel efficient when touring.

[phil brookman]

hi sent u my ph number hope to liase with u ,,,i am often at north moor and breighton ...be very interested in seeing it mine evra is a d11 29b i think 68x 53.5 pitch not sure how the d11 28 compares with that