KIND REGARDS

Thomas Giddings

n360tg@earthlink.net

727 858 1772

On Jan 4, 2013, at 2:48 PM, Bill Bradburry wrote:

Bobby,

Thanks for this info.  I had originally decided that I would stay away from a turbo on the Renesis, but I have come to realize that I will not be happy with the current power output.  My plane is heavier than the RVs that most are using and as a result, I just need a little more punch.  Actually, I would rather go with a 20b, but the expense and the size of the job kind of get in the way.  I think I could add a turbo a little easier and cheaper than changing to a 20B.  But, having never considered a turbo, I am starting from scratch on what and how to do it.

So, oil feed, I suppose I could either put in a “T” fitting at the oil pressure sender, or I could use the original oil pressure tap under the filter stand with an elbow to feed the turbo.

Then, oil drain, I don’t see how a turbo could be mounted high enough on the rotary to provide a gravity drain into the oil pan.  I have installed the older 13B pan under the mount plate, and my engine holds about 8 qts of oil up to just below the bottom of the mount plate.  Even if I somehow modified the oil pan and lowered the oil level, it seems that it would still not gravity feed from the turbo because of how low it seems that the turbo would have to be mounted.  I would really like to see some pictures of how the turbo was mounted.

Then, water cooling of the turbo,  I have a heater hose set up that I am not currently using that I suppose I could run thru the turbo to cool it.  I have read that it may not be necessary to do this.  What are people doing about the water cooling?  Use it or not?

Then some questions about your chart.  I have not seen 7125 rpm on my engine, but I am pretty certain that I am not getting 175 HP at 5700 rpm.  In fact, I doubt that I am getting much more than that at 6500 rpm.  Where did you get your numbers and do you think that these hp numbers are what you are really getting while NA and while boosted?  It may just be that my plane is about 500 lbs heavier than the RVs, but back when I was trying to turn the same prop that Ed has, I could only get about 5300 static where he was getting 6000 with that prop.

I don’t understand how you are cooling the intake charge if you don’t have an intercooler??  What are you putting the water injection on?  Radiator??  You are not spraying it into the intake???

Please direct me to some info on the “surge line”.  I have heard of it, but don’t understand it or really know what it is.

If I could get the HP numbers that you show below a sea level under boost, I would be a happy camper!!

Bill B

Bill,

The rear iron housing feed is not drilled but can be. Mine was tapped and plugged during assembly. You could also feed from the oil galley at or below the filter pad. Might be able to use the stock oil pressure sender port. Not sure about the return with a stock oil pan. I have a deep pan and can keep 4.5 quarts below the oil return fitting in both climb and decent attitudes. I added and plugged an oil return last year in case I decide to swap out the super charger for a turbo. I think you can safely boost the renesis 10:1 rotors with 3-4 pounds as long as your intake charge is cooled and you don’t have a lean fuel condition. I run 38-40” MP for takeoff and initial climb. No intercooler but I do use water injection for a safety margin.

The table below may contain errors and is a work in progress. I believe an effective turbo system would need to be capable of producing 6-7 pounds to provide enough exhaust flow at altitudes up to 18K. The turbo surge line becomes a problem with cruise rpm and higher pressure ratios. An intercooler appears to be necessary. I used a Texas summer OAT of 100F as a starting point for calculating the intake temperature.

Bobby

Am I wrong?  I don’t think that there is a stock turbo oil source and return on the Renesis?  It is not factory turboed. 

Bill B

How are the folks with turbos handling the plumbing?  Where are you picking up the pressurized oil and where/how do you return the oil to the crankcase?  I read in the install instructions that the oil drain line should be one inch in diameter, return above oil level in the crankcase, and have no traps in it.  That doesn’t seem possible with the rotary?? How are you doing it?

 

How far would it be safe to boost the Renesis with the compression at 10:1?

 

Where are you picking up the water for the water cooling of the turbo?

 

Does anyone have any good pictures of the installation that shows these things?

 

B2

 

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From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Steven W. Boese
Sent: Thursday, January 03, 2013 5:53 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: turbo manifold

 

Rich,

 

A load cell was installed on one side of the engine mount to measure torque.  HP was calculated from the torque and the RPM.  Most installations with a Renesis engine appear to be using a higher gear ratio than the 2.18:1 ratio of the reduction drives that I have.  This lowers the limit the of engine RPM that I am able to achieve with a prop suitable for flight.

 

The HP required to turn the prop at a given static RPM does not change if the atmospheric conditions haven't changed.  At the highest MAP of 21.5" shown on the chart for the NA 13B, the 13B HP is very close to the HP of the Renesis at that same MAP.  The test data on the chart was generated as a first pass at assessing the suitability of turbocharging the Renesis compared to the 13B engine.  None of the configurations should be considered to be optimized. 

 

Steve Boese

RV6A, 1986 13B NA, RD1A, EC2

     

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From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of argoldman@aol.com [argoldman@aol.com]
Sent: Thursday, January 03, 2013 2:43 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: turbo manifold

I had assumed that these were dynamometer results. By what method did you ascertain the HP listed?

Interesting results. If the blades stalled (overpowered) at such a low RPM would it be correct to assume that at that RPM the engine was producing more power than the non Renesis engines at the same RPM with the same prop???

I am so confused... interested also in perhaps turboing the renesis in the future??

Please help

Rich

 

 

 

-----Original Message-----
From: Steven W. Boese <SBoese@uwyo.edu>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Thu, Jan 3, 2013 2:55 pm
Subject: [FlyRotary] Re: turbo manifold

Bobby,

 

I honestly don't know what the exhaust sound was like.  The control panel for the test stand is on the opposite side from the exhaust outlet.  Also, at RPM above 5200, the 3 blade Warp Drive prop was stalled and the prop noise was just deafening.  I could feel what seemed to be ground vibrations in my feet so testing higher power levels was disconcerting.  At RPM below 5200, the noise was similar to having the GM diesel truck muffler on the NA 13B.

 

Steve

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From: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Bobby J. Hughes [bhughes@qnsi.net]
Sent: Thursday, January 03, 2013 1:33 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: turbo manifold

Steve,

 

How did it sound without a muffler? I removed my belly muffler for a speed run and it was not tolerable in the cockpit. Only picked up 1-2 mph so the muffler is back on.

 

Bobby