Savannah VG Prop Choice

[Bell Driver]

About to go prop shopping.  Savannah VG with Jabiru 2200.  I'd appreciate members suggestions--what are your favorites?  My bias is toward climb performance.  2 or 3 blade?   Ground adjustable?  If not, size and pitch.

[IBob]

I would recommend going to JG's website Stolspeed and reading the Props Comparison (scroll down to find the link on the left):
https://www.stolspeed.com/

It's an interesting and informative read on props, tested on JG's Savannah VG

In fact, the whole site is interesting and informative.

[Bell Driver]

Thank you for the reminder.  Great website!

[IBob]

Bell, there is real depth of Savannah experience in Australia, while here in New Zealand we are a bit later to the party.
I think I'd be right in saying most Savannahs in this part of the world run 100hp Rotax 912 with a 3-bladed ground adjustable prop.
Bolly, which is an Australian brand, are popular for the local builds, and I have been very happy with mine.
As you can see on this site, there is also real interest in the E prop, which seems to be giving good results on various aircraft.
And there is a fair bit of interesting and useful debate on how to arrive at best pitch.

 

Let us know what you decide, and how you go!

[Kyle Communications]

He has a Jab engine so only certain props can be used because it is a direct drive engine

 

Eprop are testing props for those style of engines now and will soon release their versions. There will be 2 and 3 blade available I am told

 

 

 

 

 

[Bell Driver]

I'd love to have another 15-20 hp (or more), but Jabiru 2200 is running well and problem free, so just looking to get the best possible performance possible from it-recognizing its limitations.  If I were to change engines, the Viking 130 would probably be the frontrunner.  Outstanding  performance in Zenith 701.

[Bell Driver]

Looking forward to Eprop release for direct drive engines.  Appreciate all comments and suggestions while I'm exploring  this.

[IBob]

Maybe another way to phrase the question would be to ask what sort of props people here are running on Jabiru 2200 engines?

[Bell Driver]

Excellent suggestion.  Love to hear from Jabiru 2200 powered Savannah VG owners.  What prop are you running?

[Kyle Communications]

Here in OZ most seem to be running 2 blade wood props but some do use the carbon fibre 2 blades

[Bell Driver]

Presently using a wood 60X40 (from previous owner).  Climb RPM 2900 (confirmed by Tiny Tach)  Rate < 500fpm at sea level with weight at 1080 (have the increased gross wt. 1234 mod.)  Don't presently have an accurate full throttle, level flight number.  What performance are Jab 2200 operators getting.  Climb  rates of particular interest.

[eightyknots]

On 17/04/2021 at 12:23 AM, Bell Driver said:

I'd love to have another 15-20 hp (or more), but Jabiru 2200 is running well and problem free, so just looking to get the best possible performance possible from it-recognizing its limitations.  If I were to change engines, the Viking 130 would probably be the frontrunner.  Outstanding  performance in Zenith 701.

Viking 130 engines, although really good, are heavy.

 

If you changed to a Viking 130, you may just have enough weight remaining for the pilot and the tanks filled with fuel and you'd reach your extended 560 kg (1,234 lb) weight limit. You will only be able to carry a feather for a passenger.

 

 

Edited April 18, 2021 by eightyknots

[Bell Driver]

True, weight would be tight--wallet would be much lighter though😋   Really  hoping  Jabiru soldiers on so no engine change has to be considered.

[IBob]

Bell, here is a publication from the British Microlight Assoc:

https://www.bmaa.org/files/hads_hm10_savannah.pdf

 

Right at the end are performance figures for the for the VG/Jabiru (but with no information on weight).

 

They quote 860fpm for VG/Jabiru(1-4). If you go to the table near the top (you have to look for the VG, not the plain Savannah), the first has a 65" prop pitched very fine, the second and third have 62" props, and the fourth has 60" pitched fine

 

They then quote 600fpm for VG/Jabiru (5 and LS). These are 61" props pitched medium.

 

These figures are suspiciously rounded and consistent, but it looks from that as though you are better with a slightly larger prop pitched a little fine. Which would make sense: looking at JG's comparative study the only prop that didn't quite perform was the smaller diameter one.

[Bell Driver]

Thanks for the link.  Agree that it suggests larger diameter pitched fine.  Helpful!  Noted that max RPM is shown as 3100 and Max Gross weight is 450kg.  

[IBob]

I should add that I don't pretend to know anything about props, Bell, apart from the one I'm currently using.

 

Apparently the standard convention is to measure the pitch at 75% of the radius (out from the centre), but for some reason 2 of those props have been measured at or near the tip, so we can't say what the pitch is when compared to the others.

About all I can make out from that document is that most of the props are slightly larger than what you have.

[Bell Driver]

Though still researching, Sensenich ground adjustable for Jab 2200 is front runner.

[eightyknots]

Did you consider using the E-props direct drive propeller?

[Kyle Communications]

Its not available yet Hank...they are almost finished testing though

 

[Kyle Communications]

Actually just ordered a Eprop for a guy over there in NZ about to build a savannah

 

[eightyknots]

2 hours ago, Kyle Communications said:

Actually just ordered a Eprop for a guy over there in NZ about to build a savannah

 

I will most likely line up for one as well.