----- Original Message -----

From: JJ JOHNSON

To: Rotary motors in aircraft

Sent: Wednesday, November 19, 2003 12:28 PM

Subject: [FlyRotary] Re: Renisis

Ed, and List

 

    Thanks for your great replies. I'm curious as to what it would take to turbo the Renisis engine or if that's even a possibility. From where I stand right now I'm just trying to balance my choices. Which come down to 20B or Renisis. I would like to be able to get 275-300 ponies continuously so that pretty much op's out the Renisis, unless a person can turbo it? I'm not totally excited about the extra weight [w/ the 20B] but sometimes that's the price to pay. I'm wondering if some of you flying rotary people can tell me your personal rpm red lines for your a/c. I'm wondering if anyone has ever taken the time to graphically extrapolate the life of the apex seals vs. rpm. [I'm sure its not a linear graph] Can a guy go and do the nesc. engine upgrades to enable it to run 7500 continuously? Would the TBO go from 1500 hrs to 500? or.. or..or..? I know some of these questions are just kinda .. out there.. and there is no defined answer but I'd like to hear your opinions. I wouldn't feel bad if I knew that w/ the Renisis engine I could run it turbo'd at 7500-8000 rpm and know that as long as I did the apex seals[or whatever time limited part] every 500 hrs I was ok. I'm sure some of the racing crowd has had some experience is this regard, slightly different use's but.. 

 

I'm also sure most of you are shaking your head going... this nut case............   ;-)

 

Thanks again for the help

 

Jarrett

----- Original Message -----

From: Ed Anderson

To: Rotary motors in aircraft

Sent: Tuesday, November 18, 2003 7:30 PM

Subject: [FlyRotary] Re: Renisis

Jarrett,

 

    I'll take a stab at your questions.  First, the HP rating of the Renesis is in a bit of flux.  It was orginally listed as approx 250HP at somewhere around 9000 rpm.  However, once folks got their hands on some and put the on dynos, it became apparently that the engine did not produce 250HP at least in its stock state.  The latest figure I recall was in the vicinity of 230 HP - still not bad.  However, if you do a search on the web on Renesis you may find some more recent figures.

 

I don't think you will find any maximum continous ratings for any of the rotaries.  Clearly the higher RPM you run the engine the more stress and wear.   I personally have no quams about running the older 13B at 6000 rpm the entire flight, although I normally fly it between 5200-5800 due to the lower fuel burn.

 

The literature indicates that the Renesis gets apporx 20% better fuel economy - thats the good news, the bad knews is I understand that is only gain occurs only at the lower rpms and that at the rpms we would normally run it at - the 20% gain decreases considerably.   No free lunch - you want power, you burn fuel.

 

Tracy's 2.85:1 and EC2 EFI should work with no problem. The weight of the engine might be a few pounds less than a 13B but nothing significant.  The rotors are a pound lighter each and so the counterweights are probably lighter as well, so maybe a 5 -10lb reduction in weight over the 13B block - nothing significant in weight savings  like aluminum side housing would provide.  I think it uses direction ignition (one coil per plug) so that might save a few pounds over the heavy 13B ignition system. 

 

My personal opinion is that you can probably gain the same power out of a 13B if you have the rotors lightened, heavy duty bearings/harden gears and the entire rotating assembly dynamically balanced so you can wind to higher rpms.  Would also need the right induction and exhaust system.  I mean the racing guys can get over 250 HP with the NA 13B - however, their reliability might be less than you would entertain for an aircraft application.

 

Lynn could probably address what you can get out af a 13B better than anybody on the list

 

Lynn??

 

JJJ here are a couple of URLs on the Renesis that might help

 

http://www.rx8.co.nz/Rotary/renesis.aspx

 

 

http://asmic.com/collect/rotary1999/rotary_e.pdf  36 page PDF on the rotary engine with some stuff on the Renesis

 

Hope it helps

 

Ed

 

Ed Anderson
RV-6A N494BW Rotary Powered
Matthews, NC
eanderson@carolina.rr.com

----- Original Message -----

From: JJ JOHNSON

To: Rotary motors in aircraft

Sent: Tuesday, November 18, 2003 12:19 PM

Subject: [FlyRotary] Re: Renisis

Question for the list. I've seen lots of numbers thrown out there as to how much power this engine is 'supposed' to produce. I'm wondering if anyone has some concrete numbers as to how much 'continuous' hp's one can expect at what rpm [what is the max continuous RPM recommended?]and at what specific fuel burn? Also can this engine be turbo'd? I understand from the Factory [in the Rx8] its NA.  Tracy's 2.85:1 unit should work on this engine??  As well as his electronic gizmo's? How far is this engine as far as weights [installed] from the 13B?  I've got lots more but lets start there. [Or maybe someone has a web link they can pass on that helps w/ these questions] I apologize if some are these [ I suspect they probably are] redundant.

 

Thanks

Jarrett Johnson