Hi! Ken

Do you you cut on a taper, where does your taper start? or do you just skim 0.015" off each side for a total of 0.030". I just measured the two rotors that were in a "GOOD" running 92 13b NA & got a reading of 0.017 to 0.026mm, I guess they are toast.

 

 Georges Boucher

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

 

From: Rotary motors in aircraft

Date: 04/16/05 18:54:27

To: Rotary motors in aircraft

Subject: [FlyRotary] Re: New rotors, New housings

 

   That's off each side, Rob at Pineapple racing takes 20 thousandths off each side but I figured the 15 should do it.

    Ken

 

Ken,

Is that all off the one side - that much off each side - or half off each side !?

George ( down under)

 

I wouldn't think about putting an engine together without shaving the rotors, I cut 15 thousandths of an inch at the tip and tapper it off to zero where the blueing is.

  I have thought about running a RX-8 engine but I don't think the high compression would work well with the 100 hp increase of nitrous I require to lift a heavy load out of the water.

  Ken

Ed,

Ken's comments reminds me to say that I remeasured the width of the RX8 rotor for a more accurate measurement and it appears after a number of measurements that the RX8 rotor are only slightly wider, this being .04mm in the gear area and only .02mm at the apex.

 

This I believe won't be a problem at the RPM and power settings we generally use. However it would represent a small problem in Ken's application as he uses NOS at take-off and at that high power the E-shaft does flex a little - this causes the rotors to skew slightly, binding at the apex areas. Ken already has this problem with the RX7 rotors and skims them to eliminate this problem. This is a remedy that many in the racing game use as well.

 

 I don't believe there's a problem with the single rotor application and won't be skimming the rotor. 

 

Hope that helps!

George ( down under)

  I would look into getting 85-85 GSELE rotors with the 3 mm seals, you would also need the weights to match them, then machine out your rotors for a spare engine, you may need one to bale you out in the future, if you keep this up you may knock me off the seat as president of the dead stick club.

  I am now running rotors machined out to 3 mm seals and at about 400 hrs on them I can tell by checking through the exhaust port that the seal grooves are getting V'ed out and getting sloppy so I am now putting another engine together, on this one the rotors are in prime shape so I think I will run Tracy's 2mm seals.

 Also I think that the groves may be hardened and by machining the groves out makes them softer as they shouldn't have worn out in only 400 hrs.

  Ken

Well, the decision has been made.  Thanks in part to the wife's continued interest in my warm body on  cold winter nights, the decision has been made to purchase new rotors and rotor housings.  $$ but apparently I am worth it {:>)

 

I looked into milling out the slots to 3mm and that would have been the cheaper approach - but cheap approach is probably partly responsible for me being in this situation - so going to try a different approach this time.  Besides leery of using a rotor which clearly has been subjected to sufficient loads to scrape metal off its surface and peen over apex slot.

 

In the process of getting quotes.

 

Ed

 

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

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