user 116312
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- Joined
- Aug 20, 2020
- Messages
- 16
Was wondering whether 80 hp (Jabiru 2200 or Rotax 912) is a viable option for Sonerai I airframe?
Where would you locate the radiator , oil cooler and muffler?Here are some initial efforts at a cowl for the Rotax.
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RhinoWhat program is it that you're using for your 3d modelling?
Thank you, but only one of the screenshots is a render. The others are an emap on the surfaces, with the surfaces set to 40% transparency.Beautiful rendering - i'd like to learn to do the same!
Good question. This is only at concept stage, so while the thrust line is basically set, the rest isn't. Drawing the cowls using a surface modeller means that once a concept is decided upon, it can (within limits) be scaled in any direction, and at any point to accommodate a fitment. One real concern I have is the weight differential between a Rotax/Jabiru installation and a VW one. If the line drawing that came with my plans is correct, a Rotax/Jabiru fitment will need to be significantly forward of the VW one.Where would you locate the radiator , oil cooler and muffler?
That is great work!Can't speak for certain but I think a member here Cosmic is running a 3300 Jabiru on his S1 that I've heard is a hot rod. His fuselage is covered with sheet aluminum which I'm sure helps the CG issue hanging a larger engine off the front. Curious to know what he had to do to make it work???
I'm working on something similar but using a standard 2276cc VW driving an engineered coaxial reduction mounted to the "right" side of the engine. No bearing adder/modifications to the engine/case needed and mounts to the existing transaxle bolt holes. Only adder is a second stage to the oil pump for thrust bearing/planetary lube/scavenge. I'm at 18lbs added weight to a "flywheel drive" install but can run as large a prop as I want - have to stay within MOI numbers the reduction was designed for. Calculated thrust numbers not confirmed but almost double what a direct drive will put out with prop size and HP limits. Max engine RPM 4000 (should consevatively top 90hp at max RPM) and prop output "standard aircraft" 2750rpm. Shooting to have the reduction completed this summer. I have all this drawn in Solidworks (Tks to EAA) and some parts finished including custom flywheel with inertia ring with planetary that is loctited and ready to install. S2 tube fuselage (solo only) and RV 3 gear in the model now with 65" prop but I do have a complete S1 airplane (not currently flying) I may modify to make all this work. And don't ask about the wing...tapered trailing edge and increased chord significantly on root side to allow for larger spar section. Comes out to same wing loading with additional weight. Same engineer who did the reduction will run FEA's on multiple spar configurations I have drawn. Just having fun! (Working on exhaust now - mirrored just to see what it would look like)
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I would consider 80hp barely adequate. Can I assume you are familiar with Robin Austin's machine?That is great work!
I am aiming to build a Sonerai I as close to the original as I can reasonably manage, but the limited support options for a VW fitment is the reason I am considering other power plant alternatives.
Another concern I have is to whether or not 80hp is too much for the basic design.
I live in the Blue Mountains NSW.I would consider 80hp barely adequate. Can I assume you are familiar with Robin Austin's machine?
He has posted information about it here.
https://www.sonerai.net/threads/world-record-plane-12-years-on.4975/#post-37851
Where in Australia are you, if I may ask? I'm in South East QLD
It is my understanding that they were designed for VW engines and 80hp is about all you can get out of them reliably in an aero application. They don't really have enough finning to get rid of the heat and when you add typical Australian temperatures, it doesn't get any better.I live in the Blue Mountains NSW.
Perhaps I didn't quite understand, but I understood that the original Sonerai I would have had around 65HP, and the Sonerai II was designed for 80HP. Is this correct?
Yes. I have seen Robin's website and it is very impressive!
The Jabiru engine does polarize opinion. I owned one of the original Jabiru's that came with a 1600cc engine. A few months later the 2200 became available so I upgraded. I instructed in that Jabiru for around 1500 hours and it was worked very hard. The only problem encountered was the original valves needed some work at around 400 hours. What some may not realize is that there are 4 phases of Jabiru engine. Phase 1 used solid lifters and it was reliable. Phase 2 and 3 used hydraulic lifters and these engines were less reliable but still satisfactory for many people. Of course if you have had a failure then your opinion will be negative. Phase 4 is the current engine and I have only heard good things about it.Love your work. Might cop some criticism for this but early stages of a S1 build here in Brisbane. Also planning a 3.3 jab like cosmic then planning on copying the carbon rear like Mike Prat did on scrappy.
Just to clarify. 120hp in a Sonerai I airframe and (probably more importantly), a Sonerai I wing. Is that correct? If so, what are the dimensions of the propeller?The Jabiru engine does polarize opinion. I owned one of the original Jabiru's that came with a 1600cc engine. A few months later the 2200 became available so I upgraded. I instructed in that Jabiru for around 1500 hours and it was worked very hard. The only problem encountered was the original valves needed some work at around 400 hours. What some may not realize is that there are 4 phases of Jabiru engine. Phase 1 used solid lifters and it was reliable. Phase 2 and 3 used hydraulic lifters and these engines were less reliable but still satisfactory for many people. Of course if you have had a failure then your opinion will be negative. Phase 4 is the current engine and I have only heard good things about it.
Have owned 2 VW powered aircraft (Tipsy Nipper and Corby Starlet) and in my opinion the Jabiru is superior. The VW engines can only produce around 80hp reliably as M61A1 says. When I sold the Tipsy Nipper, the new owner put a Jabiru 2200 in it and it was smoother and performed a lot better.
With regard to the best engine for a Sonerai, the Jabiru 3300 seems a perfect match. Using a standard length engine mount (but stronger) the CG came out exactly where I wanted it. The plane will do 190 knots flat out and cruises around 175. Handling is similar to a Pitts Special that I used to own but the Sonerai feels a lot lighter. I have not spun my Sonerai so cannot comment on how the longer engine and nose affects spin recovery. Bill from Canada has a 3300 in his Sonerai 2 so if he sees this he may care to make his own observations about the suitability of the engine.
The Jabiru engine does polarize opinion. I owned one of the original Jabiru's that came with a 1600cc engine. A few months later the 2200 became available so I upgraded. I instructed in that Jabiru for around 1500 hours and it was worked very hard. The only problem encountered was the original valves needed some work at around 400 hours. What some may not realize is that there are 4 phases of Jabiru engine. Phase 1 used solid lifters and it was reliable. Phase 2 and 3 used hydraulic lifters and these engines were less reliable but still satisfactory for many people. Of course if you have had a failure then your opinion will be negative. Phase 4 is the current engine and I have only heard good things about it.
Have owned 2 VW powered aircraft (Tipsy Nipper and Corby Starlet) and in my opinion the Jabiru is superior. The VW engines can only produce around 80hp reliably as M61A1 says. When I sold the Tipsy Nipper, the new owner put a Jabiru 2200 in it and it was smoother and performed a lot better.
With regard to the best engine for a Sonerai, the Jabiru 3300 seems a perfect match. Using a standard length engine mount (but stronger) the CG came out exactly where I wanted it. The plane will do 190 knots flat out and cruises around 175. Handling is similar to a Pitts Special that I used to own but the Sonerai feels a lot lighter. I have not spun my Sonerai so cannot comment on how the longer engine and nose affects spin recovery. Bill from Canada has a 3300 in his Sonerai 2 so if he sees this he may care to make his own observations about the suitability of the engine.
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