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13B Rotary in an RV-9A??

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David Clifford

Well Known Member
Is anyone, or has anyone put a 13B rotary in the RV-9A? I sold my Cozy MKIV project and now have the engine I planned to install in it, a 13B Renesis. I still am undecided between the RV-9A or the RV-10 so i'm hanging on to the Renesis until I know for sure what my choice of power will be. Thanks for your thoughts. Dave
 
Bernie Kerr did, and in fact has the entire firewall forward for sale.

As I understand it, he's got it well debugged and running well, but is thinking about switching back ot a Lycoming for simplicity.
 
True, but with constant speed operation, there is no reason not to port and tune the (intake) manifolds for peak power. Most of the tuned engines are getting 180-200 HP w/o turbocharging.

The new Renesis version should also be considered- a little better design w/increased output. Im leaning towards the Renesis myself, because the parts are newer and should be available in the future, mostly because it is a bit more efficient.
 
Cobra,

That's true, but my point was, that a stock engine would pretty much take care of an RV-9x without doing any extra work, and you would not have to worry about limiting power. Of course, the Renisis is a different animal, and it probably does not make a lot of sense using an older 13B if you can find a Renisis (unless you are a cheap ******* and think you got a good deal on an older 13B). With the Renisis, you do need to worry about having too much power. Ouch, too much power, now that just doesn't sound right.

Cheers,
Tracy.
 
There is a fair amount of modification work involved with converting any rotary engine to av use- mostly maniflold weight reduction and installing critical system redundancy.

The power/torque curve with rotaries are nearly linear with rpm (make more power as the rpm increases; unlike piston motors, more like a turbine). The renesis has higher output mostly because it is tuned to run a little faster (peak power, 250HP @8500 rpm) in auto use during normal operation. Either version can spin up safely, if tuned to do so, but most av users keep the engine speed a lot slower than allowable limits anyway. It is nice to be able to change prop pitch and speed up the engine when more power is needed for climb out in hot/high conditions. The renesis is a bit lighter and has a slightly better port design that helps efficiency at idle/mid range speeds, but other than the air/fuel induction system, are NOT much different than the earlier versions of the motor.

Other nice perks are rotary RV users can use the in flight adjustable, light weight, and cheap IVO prop --save significant dollars over the expensive MT and other hydraulic C/S props, and of course, enjoy mogas savings during normal operation.
 
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David Clifford said:
Is anyone, or has anyone put a 13B rotary in the RV-9A? I sold my Cozy MKIV project and now have the engine I planned to install in it, a 13B Renesis. I still am undecided between the RV-9A or the RV-10 so i'm hanging on to the Renesis until I know for sure what my choice of power will be. Thanks for your thoughts. Dave
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Hi David,

Welcome to the "dark side" of metal airplanes and alternative engines. Resistance was obviously futile.

Renesis would be nice flat rated (seriously) on a 9A to 160hp, a tad on the low side for a 10 maybe. That would be some kinda sound at 9000 rpm though! :)
 
Well the Renesis is what I have sitting in my shop now. I'm just trying to find out if its a viable engine for the 9A, or even the 10. Mine was built by Bruce Turrentine for my Cozy MKIV. Minor porting was done along with ceramic coated rotors. Bruce publishes 225 hp normally aspirated. That would be in the lower end limits for the 10 which has/had the Continental IO-360 @210 hp. One advantage with the rotary is the ability to use a low cost C/S Ivo prop safely instead of the $11,000 MT.
 
Dave,
If you decide to go with the 10, I'd trade your Renesis in on an older 20B 3-rotor. They are easily capable of reliable 300 HP output and probably the ideal RV10 powerplant.

The option to turbocharge your renesis is always open, but there is not much positive experience yet posted with turbocharged Renesis w/ its high compression rotors.
 
You've got it, might as well use it. Bruce has a great rep and I'd love to see another rotary RV flying. Now you just have to decide, 2 or 4 seats? Welcome aboard!
 
cobra said:
Dave,
If you decide to go with the 10, I'd trade your Renesis in on an older 20B 3-rotor. They are easily capable of reliable 300 HP output and probably the ideal RV10 powerplant.

The option to turbocharge your renesis is always open, but there is not much positive experience yet posted with turbocharged Renesis w/ its high compression rotors.
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There actually are a few turbos flying with great success, The turbo needs to be properly sized for the application and care must be taken to not overboost. I do not plan on a turbo for the Renesis. Bruce recommends a supercharger for my Renesis so if I do anything in that direction,,,it will be a Vortec supercharger as he recommends.
 
rv6ejguy said:
You've got it, might as well use it. Bruce has a great rep and I'd love to see another rotary RV flying. Now you just have to decide, 2 or 4 seats? Welcome aboard!
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Thanks rv6ejguy! You have provided great info over at the canard forum and I suspect I will find the same here! 2 or 4,,,,thats my dilema. I know what I want,,,,,I just got to convince the wife its worth the double costs of the RV-10, so she will be able to fit all those treasures she will find in our travels.
 
Renesis Mods

I am installing a Renesis in my RV7. I have not actually installed an older style 13b, but it seems from the people I know that are doing so, the Renesis requires less mods to make it fit. EG, the water pump does not need to be cut and welded (or moved altogether) It is supposedly a little easier to control the sound. ETC... Not huge things, but little things take a lot of time. Trust me. I am nearing first engine start. Wiring the FWF right now, then will see if it makes noise!
 
N713R said:
I am installing a Renesis in my RV7. I have not actually installed an older style 13b, but it seems from the people I know that are doing so, the Renesis requires less mods to make it fit. EG, the water pump does not need to be cut and welded (or moved altogether) It is supposedly a little easier to control the sound. ETC... Not huge things, but little things take a lot of time. Trust me. I am nearing first engine start. Wiring the FWF right now, then will see if it makes noise!
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Great Ben! Keep us updated with posts of your progress.
Dave
 
David Clifford said:
Thanks rv6ejguy! You have provided great info over at the canard forum and I suspect I will find the same here! 2 or 4,,,,thats my dilema. I know what I want,,,,,I just got to convince the wife its worth the double costs of the RV-10, so she will be able to fit all those treasures she will find in our travels.
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I fly a 6A now and am building a -10 now just for these reasons. Needed more space to haul stuff like bikes, skis, kitchen sink etc. Take the rear seats out of the 10 for a 2 person trip and you have a ton of room and about 400-500 lbs. worth of payload over the 2 seat models. I remember telling my girlfriend at the time on one trip- you can take 42 lbs. worth of baggage. Her response was- WHAT!!! We had the 6A jammed to the canopy top with stuff.
 
There actually are a few turbos flying with great success, The turbo needs to be properly sized for the application and care must be taken to not overboost.

I do know of a bunch of successful turbocharged 13b's, no Renesis ones yet; in fact, the car guys have had problems getting tuning right with their turbocharged Renesis trials. No doubt they will find workable solutions in the near future.

I believe you got the turbocharger sizing suggestions wrong- the problems so far have been with overspeeding Mazda OEM turbos, not overboosting them. The automotive OEM units are too small for constant speed use @ 6000 rpm; larger turbochargers are needed.

Nothing wrong with superchargers, except they require belt drives that frequently slip, occasionally fail, and always rob power from your crankshaft.
The superchargers are notorious for excessive heat generation when used more than seconds at a time, unless you install a water coooed intercooler (heavy). Centrifugal types (like the Vortech) are the worst offenders, because their boost peaks quickly at high engine speeds. Id suggest you look at a roots or whipple style supercharger instead. IMHO, turbocharging is a much better solution.

Turbos convert waste exhaust heat as their power source so there is no crankshaft power lost when the turbos are not compressing air. The reduction in heat energy also reduces exhaust noise, another plus.
 
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