Recently, I had been thinking about the whole engine thing...and it certainly is something very important to the Sonerai's operation. Now people have used Continentals and I think someone is even using a Corvair...I've even heard of someone trying to put in a Jabiru 3300. I certainly won't be doing anything that far out.
The two common choices would be either the VW2180 which is what the aircraft was designed for, and secondly, the Jabiru 2200 engine. Both these engines are very suitable for the Sonerai.
The Jabiru 2200 has a firewall forward (FWF) kit available for around a hefty AU$3000. No matter what its exact price is, it was certainly a lot more expensive than the FWF installation of the VW. So all in all, the VW installation, would certainly be the choice for the thrifty conscious person.
The VW2180 engine itself comes at a moderately cheaper price than the Jabiru 2200 engine also. So all up things are looking good for the VW 2180 in terms of cost. So what makes the VW cheaper than the Jabiru? I spent alot of time thinking about this, keeping reliability in mind. At the moment, to keep a long story short, I am choosing to use the VW2180 from Great Plains Aircraft Supply and there are a few reasons for this:
- The Sonerai aircraft is designed specifically around the VW 2180. No or minimal modifications required.
- The VW 2180 has a known history and is well proven. We know its strengths and weaknesses
The drawbacks of using the VW 2180.
- Slightly less power than the Jabiru 2200
- Heavier than the Jabiru 2200
- Vacuum pump is not a standard addition due to added weight.
- No mechanical fuel pump (although not really required for this gravity feed installation).
I should also mention some of the points that benefit from using a Jabiru 2200.- Mechanical fuel pump (a good backup for the electrical fuel pump).
- Easy to include a mechanical vacuum pump to run an attitude indicator.
- Added torque (85hp)
- Hydraulic Lifters - less maintenance (but who cares when your only operating low hours private operation).
Some points now about the drawback of using a Jabiru 2200.
- More expensive than the VW 2180.
- More modifications FWF and other changes forward of the canopy.
- Different weight and balance.
- Not endorsed by the designer (John Monnett).
- Aircraft manual requires modification.
The Jabiru engine is a reliable engine which at the time of writing this, I have 100hrs flying behind (both the 2200 and 3300 total). I think it is superior to the VW 2180 because it light, more powerful and designed specifically as an aero engine, but in saying this, it does not mean that the VW 2180 is a less suitable aero engine. When looked after the VW engine is reliable and suited to the Sonerai.
Because the engine is readily available there are a number of different supplier of VW 2180 conversions. The most recognized being Great Plains Aircraft Supply who have supplied more of these engines than anyone else. Since I am not an engine expert, Great Plains also offer an assembly service to build the engine for you. This is what I will opt for. Other high profile suppliers of the VW2180 engine include http://www.sonexaircraft.com and Revmaster. I have found that Great Plains have done more research and development on the VW engine aero conversion than anyone else to make it the most reliable VW aero conversion engine available.
I am always thinking safety and reliability of an engine and there is no evidence of the VW compromises either of these 2 important factors.
Footnote added: Since I've been doing research on the prop type...the diameter is limited to 54" due to ground clearance. This means that the faster turning VW engine is more suitable as its maximum torque occurs at higher RPM (3400rpm = 75% cruise for the VW where the Jabiru has a 75% around 2800 rpm).
Let me know your thoughts. If you have any comments on this, your input is appreciated.
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