Engine choice Sonerai I

[Brisvagas]

Thanks Cosmic. Post like yours motivates

 

[M61A!]

rebuild the VW every 200hrs

That would mean rebuilding once a year for me.

 

[cosmic]

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?

Yes a Jabiru 3300 6 cylinder 120 hp in my Sonerai 1. The ailerons are operated differently from plans because of the seat position which is lower than plan. I installed wing walks on both sides because I built my S1 as a low wing so the centre section would probably be stronger than standard. I stay under 4G and have registered the plane with a MTOW of 410 Kg (904 lbs). For a typical flight the weight would be around 380 Kg (838 lbs). The prop is a Bolly 3 blade 153 cm.

 

[M61A!]

Yes a Jabiru 3300 6 cylinder 120 hp in my Sonerai 1. The ailerons are operated differently from plans because of the seat position which is lower than plan. I installed wing walks on both sides because I built my S1 as a low wing so the centre section would probably be stronger than standard. I stay under 4G and have registered the plane with a MTOW of 410 Kg (904 lbs). For a typical flight the weight would be around 380 Kg (838 lbs). The prop is a Bolly 3 blade 153 cm.

Is your MTOW based on achieving the 45kt stall speed required by RAAus or a structural thing?

 

[Chucker]

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

I don't intend to be combative....but 80hp gives the Sonerai I a power loading of 9.375 lbs/hp. By comparison, Vans advertises a power loading for the RV-8 at 12-9 lbs/hp. I'm not sure you can find many aircraft with a better power loading than a correctly built Sonerai I with a 80hp engine.

 

[Bil4381]

I fly an S2 which came with an 85 hp engine. Due heasting on test flight the rings on one cylinder lost their seal. I eventually found a 6 cyl J3300 solid lifter engine. Should I lose power in 1 or even 2 cylinders, I'm still flying. Theres a lot to be said for power to spare.
BillE

I don't intend to be combative....but 80hp gives the Sonerai I a power loading of 9.375 lbs/hp. By comparison, Vans advertises a power loading for the RV-8 at 12-9 lbs/hp. I'm not sure you can find many aircraft with a better power loading than a correctly built Sonerai I with a 80hp engine.

 

[Chucker]

If you believe what AeroConversions says about their engine...you can get 1000 hours for an $8K engine and rebuild it for a maximum of $2K more. That is a lot of flying for $10K.

Please don't shoot the messenger...your mileage may vary. However, Fred Keip took good care of his VW engine and flew it regularly. I believe he will attest to this type of durability.

Here is the quote from AeroConversions:

What is the TBO (Time Before Overhaul) of the AeroVee?

Because the AeroVee is an Experimental aircraft engine, there is no requirement to publish or specify a TBO. We don't publish a TBO, and we really don't approach overhaul with a TBO mentality. There is no magic hour at which any engine suddenly needs service, whether certified or not.

The AeroVee will last anywhere between 700 and 1200 hours depending upon how well you treat it. If you do a good job following our instructions to assemble the engine, as long as you keep the temperatures in the green, change the oil at proper intervals, keep the valves adjusted, and provided you are flying often-enough (a big caveat with all aircraft engines), you will easily see 1000 hours out of your AeroVee. As long as you have good compression and the engine is not burning oil, the AeroVee is good-to-go. You will notice when the engine is not providing quite the same static RPM and that's typically a good sign that some level of overhaul should be considered.

The really great news is that core parts for the AeroVee are readily available either through us, or from numerous aftermarket VW racing part suppliers, at incredibly low cost. A routine to moderate overhaul of an AeroVee will cost between $200 and $500. A worst-case-scenario overhaul involving replacement of all the core parts will cost approximately $2,000 in parts.

 

[Chucker]

I fly an S2 which came with an 85 hp engine. Due heasting on test flight the rings on one cylinder lost their seal. I eventually found a 6 cyl J3300 solid lifter engine. Should I lose power in 1 or even 2 cylinders, I'm still flying. Theres a lot to be said for power to spare.
BillE

I respect your choice Bill! But there are a lot more pilots flying behind 4-cylinder engines than 6. There are always tradeoffs to make. I like the idea of a 6-cylinder but am not ready to discount all 4-cylinder engines. All the best!
Chucker

 

[M61A!]

I don't intend to be combative....but 80hp gives the Sonerai I a power loading of 9.375 lbs/hp. By comparison, Vans advertises a power loading for the RV-8 at 12-9 lbs/hp. I'm not sure you can find many aircraft with a better power loading than a correctly built Sonerai I with a 80hp engine.

Perhaps I need to be more specific and perhaps I should look at which aircraft type they are talking about.
The VW is fine for the S1 as you say but the S2 at gross ends up at over 14 lbs/hp.
While I build my S2, I'm still flying my 601HD with it's 80hp. It flies well with it , but it has half the wing area again and fully loaded, I often wish it had more power especially in the takeoff.
More power is never bad and Rotax don't make the 80 anymore so the 100 hp is perfect if you can get one reasonable priced. You don't always have to buy new and most will double the 2000 hr TBO.
Heat is a killer here in Oz. I would guess it's similar in your southern states.
Marginal power with a high DA while having to be careful to manage temps is a recipe for problems or at best , very limiting to when you fly. Many of us also fly from private unimproved strips that can be a little rough, have long grass and shortish in length.

 

[cosmic]

Is your MTOW based on achieving the 45kt stall speed required by RAAus or a structural thing?

Stall.

 

[Chucker]

Perhaps I need to be more specific and perhaps I should look at which aircraft type they are talking about.
The VW is fine for the S1 as you say but the S2 at gross ends up at over 14 lbs/hp.
While I build my S2, I'm still flying my 601HD with it's 80hp. It flies well with it , but it has half the wing area again and fully loaded, I often wish it had more power especially in the takeoff.
More power is never bad and Rotax don't make the 80 anymore so the 100 hp is perfect if you can get one reasonable priced. You don't always have to buy new and most will double the 2000 hr TBO.
Heat is a killer here in Oz. I would guess it's similar in your southern states.
Marginal power with a high DA while having to be careful to manage temps is a recipe for problems or at best , very limiting to when you fly. Many of us also fly from private unimproved strips that can be a little rough, have long grass and shortish in length.

Just for reference, I flew a Stretch model with a dry weight of 590 lbs. behind a 70hp Revmaster 2100-D out of KPRC (5,000' MSL) with a 190 lb. passenger. I weigh 150 lbs. With fuel, we were pushing 1000#. Your mileage may vary!

 

[kennyw]

...My personal opinion is to go for the lower RPM reliability and rebuild the VW every 200hrs. The way I fly, an engine will last several years.

My 1835 has over 500hrs on it. Just did a compression check, its 76/78/78/74. It runs just as strong and smooth as it did the day I bought it from Smokey.

Its hand-prop only, and starts in 3 blades almost every time (occasionally, the starter [me] has a brain fart and it takes a couple of prime/start sequences to get it going).

Also, most of my flying is local area aerobatics and fun-flying. I'm mostly running 3,200-3,300 rpms, with lots of full power climbs. I've flown this little airplane almost 400 hrs in the last 4 years. Rarely does a week go by that I don't fly at least for an hour. The only engine problem I've had was the mag drive adapter had an odd wear pattern on it, discovered during the first condition inspection I did. Never did figure out how it happened, and it hasn't happened since.

Rebuild every 200hrs? I'm thinking it'll go at least 1000.

 

[SONERAI-1369Z]

I would day they are both viable but have no experience with either.