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Hey all, I was curious about what ya'll might think of this. The R-2300 is a new Revmaster VW engine, 85hp, designed to run at lower RPM than other VWs. Info here: http://revmasterautomotive.com/revmasteraviation/?p=308

I've been planning on building the Sonex kit with this engine. It produces 80hp at 2950 RPM, and 85hp at 3200 RPM. I know some of you use the AeroVee engine and you say flying the Sonex at max gross with the AeroVee makes it struggle pretty hard with a bad climb rate. Well I don't plan on flying my Sonex at max gross very often, but when I do take my wife somewhere along with a bit of luggage, I'd like to think I wouldn't have as much trouble climbing to 8,000 feet with this R-2300 engine as I would with an AeroVee. I plan to build light (taildragger, polish with no paint).

Most of you are more experienced with these engines than I am though. If I go with this R2300 engine, how many of you think I'll have problems climbing to a decent cruise altitude at max gross, on an average density altitude day?

Thank you.

Also, would an in-flight adjustable prop possibly solve the climb rate issue? Ivoprop makes an in-flight adjustable prop for a good price.

Chris,
The Revmaster R2300 has been on the scene for a while now, it is possible there are some fitted to a Sonex and maybe someone will chime in. I own an Aerovee-powered Sonex and have flown it at 1150 lbs (the MTOW at which it is registered). I would not say it "struggles pretty hard with a bad climb rate", though most of my flying is from fields below 2000' MSL and at OATs below 90 deg F. At higher density altitudes I'm sure the climb rate decreases.
The in-flight adjustable prop has some issues. The plane wouldn't qualify as an LSA anymore, and even if that doesn't affect you (now), it might make your plane less attractive to other buyers in the future. Weight, cost, and added complexity are other factors. I don't know about the IVOPROP in particular.
My take: As you only plan to fly "heavy" infrequently, I wouldn't get too hung up on the climb rate situation unless you'll be operating at high DA fields or need to meet a challenging climb gradient for other reasons (extensive vertical terrain, etc). If I've got the plane loaded up and headed somewhere, and if I can climb out of the field safely, I'm not concerned if it takes me a couple more minutes to get to my cruising altitude, as I'm already headed in the right direction and covering ground the entire time. But, I'm sure everyone has their own opinion on this.

vigilant104 wrote:Chris,
The Revmaster R2300 has been on the scene for a while now, it is possible there are some fitted to a Sonex and maybe someone will chime in. I own an Aerovee-powered Sonex and have flown it at 1150 lbs (the MTOW at which it is registered). I would not say it "struggles pretty hard with a bad climb rate", though most of my flying is from fields below 2000' MSL and at OATs below 90 deg F. At higher density altitudes I'm sure the climb rate decreases.
The in-flight adjustable prop has some issues. The plane wouldn't qualify as an LSA anymore, and even if that doesn't affect you (now), it might make your plane less attractive to other buyers in the future. Weight, cost, and added complexity are other factors. I don't know about the IVOPROP in particular.
My take: As you only plan to fly "heavy" infrequently, I wouldn't get too hung up on the climb rate situation unless you'll be operating at high DA fields or need to meet a challenging climb gradient for other reasons (extensive vertical terrain, etc). If I've got the plane loaded up and headed somewhere, and if I can climb out of the field safely, I'm not concerned if it takes me a couple more minutes to get to my cruising altitude, as I'm already headed in the right direction and covering ground the entire time. But, I'm sure everyone has their own opinion on this.

Yeah my wife isn't a fan of flying, so our XC trips would probably only happen maybe once or twice a year, and only 400-600ish miles away. It's good to know your AeroVee handles the weight acceptably.

I think maybe I got a bad impression from X-Plane 10...supposedly its flight physics are accurate, but the Sonex model with an 80hp engine set at 1150 lbs can hardly even climb at all in the simulator...like barely even 100FPM in ideal DA setting. Ends up stalling if I barely lift the nose at all. I guess I shouldn't make my judgements based on a simulator, it's not the first time that thing acted wonky. :roll:

*

daleandee wrote:Might I suggest a nice Corvair conversion? Gobs of power, cooling is not an issue, can build it yourself or buy it built, and gross weight is not a problem. My gross is 1250 and she handles that very well as others have noted. Took the wife with me yesterday to a Corvair College to show my aircraft to other Sonex/Waiex builders that are using the Corvair engine.

Your decision but I thought I would remind you of the best option currently available for the Sonex. 8~)

Dale Williams
N319WF @ 6J2
Myunn - "daughter of Cleanex"
120 HP - 3.0 Corvair
Tail Wheel - Center Stick
51.2 hours / Status - Flying
http://www.youtube.com/channel/UC49h6Qijc17_Ebfz0CbRFtg
http://websites.expercraft.com/daleandee/
http://groups.yahoo.com/group/carolinasportflyers/

You're actually not the first to recommend a Corvair to me...could I inquire as to the average cost of a new Corvair engine? Also, what's the fuel consumption like, and what type of fuel does it use? Can it use auto gas?

Hello Chris,

Great questions and responses you're getting here. I don't really know much about the Revmaster 2300 but it seems like a nice engine. It looks like it can deliver up to 85 h.p. for a limited amount of time (takeoff), and then for continuous power it will be very close to the AeroVee. In terms of VW engines for aircraft use, generally you're looking at three options: Revmaster, AeroVee, and Great Plains. Personally I know of a whole bunch of Sonexes using AeroVees, as few using Great Plains, but I don't know of anyone first hand using a Revmaster. It seems that each has their own little plus and minuses, as I'm sure you've discovered.

You could also look into a Jabiru 2200 (same horsepower, around 80) or the Jabiru 3300 (120 h.p.) as options. Some are looking into the UL engines but that's still a new development.

I'm sure Dale can tell you more about the Corvair, but there is a lot of information found at http://www.fly5thbearing.com on the Corvair. People who have them love them! Dale has a very nice example on his Sonex. Officially, the factory says that it's too heavy so you'll sacrifice some factory support, but there's plenty of support in the customers with completed examples.

I'm not trying to convince you on anything; I'm sure you have your likes and dislikes. Like Mark, I've also flown my AeroVee powered Waiex up to 1150 lbs before and while it's no F-15, performance was fine. In the summertime I need to watch cylinder head temps at gross weight, but in the winter everything is fine. I generally get around 800-900 feet per minute climb at 900-950 lbs, and it tapers off to around 500 feet per minute climb at 1150. Plenty for me, especially since 98% of my flying is solo! :mrgreen:

Good luck in your decision!!

Hey Mike, thanks for the informative reply. Looks like I'm gonna choose between either the R2300, or the Corvair.

I think my main question with the Corvair is fuel efficiency. It's got a lot of power, so the main thing I'm wondering is if it will pull the Sonex fast enough to make up for the fact that it seems to gulp fuel. The R2300 won't get you to your destination as fast, but it won't drink as much gas. The Corvair drinks more gas, but will it get you to your destination in the Sonex fast enough to make things equal out?

Daleandee, what's your typical cruise speed in your Sonex with the 120hp Corvair?

What do you think your normal mission profile will be Chris? Do you see yourself doing a lot of cross countries, or flying around locally?

Using the AeroVee (close to the same engine as the Revmaster) as well as the information from the Corvair website, I would estimate the following (these are just my guess):

Revmaster:

Low altitude cruise: 130 mph, 4.5 gph = 3.5 hour endurance until empty, 450 mile range
High atltitude cruise: 145 mph, 4.0 gph = 4 hour endurance until empty, 550 mile range

Corvair:

Low altitude cruise: 150 mph, 6.0 gph = 2.75 hour endurance until empty, 400 mile range
High altitude cruise: 170 mph, 5.0 gph = 3.25 hour endurance until empty, 550 mile range

Bear in mind that after around 2 hours I'm more than ready to get out and stretch. I've done several 2.5ish hour legs in my Waiex (Oshkosh, Crossville) without issue, but try to keep leg lengths shorter if possible. Of course, most of my flying is within 50 miles of my home base, so fast cruise speed isn't that big of a deal to me. Regardless of which engine you choose, you'll love the airplane!

My mission is gonna be probably 10% cross country at max gross with my wife, and 90% solo local stuff. I'm leaning heavily toward the R2300 now I think. The Corvair looks really nice, but it's a few grand more than the R2300 (R2300 is $8,000, Corvair 120hp is $11,500) and the R2300 is also compatible with the engine mount provided by Sonex for the AeroVee and the AeroVee baffling kit as well. Also I'm just a lot more familiar with the VW conversions in general.

Great replies...thank you.