7000 rpm static - WoW!  sounds like not enough pitch in the prop to absorb the power - tough situation to be in - NOT!

 

Regarding your 17" manifold pressure at idle - here is a comparison  of port timing information from Paul Yaw

You can see that the total open time of the PP is considerable greater than the turbo 13B.  So for a given rpm, I would conclude that since average amount of time  the PP intake is open longer to the atmosphere for the same RPM as a turbo 13B,  that the intake manifold pressure would be higher for the same rpm.  So what you are seeing just may well be "normal" for a PP port.

 

But then I don't own and have no experience with a PP.

 

Ed

 

 

 

Second and Third Generation Turbo 13B

IO 32° ATDC
IC 50° ABDC
EO 71° BBDC
EC 48° ATDC

Mazda Factory Peripheral Port

IO 86° BTDC
IC 75° ABDC
EO 73° BBDC
EC 65° ATDC

 

 

A

 

ASThis site is meant to give information

From: Mark Steitle

Sent: Monday, November 15, 2010 9:09 AM

To: Rotary motors in aircraft

Subject: [FlyRotary] Re: Hey are those 304 Stainless staples...(from David)

OK, Doug, I'll post my weekend update. 

 

As some of you may know, I have had troubles getting my 20B to run as it should.  Problems started about 3 years back when I decided to convert from the stock CAS to the Renesis style CAS.  While I did have limited success, it was very sensitive to alignment and air gap of the CAS sensor, and possibly some other issues that I am not smart enough to figure out.  I had trouble getting it to run above 5800 rpm. 

 

About a month ago I decided that enough was enough and I called Tracy to say that I wanted my EC-2 converted back to the original configuration.  I sent it back to Tracy who made the mod and upgraded the software to the latest version.  I got it back on Friday and was anxious to see how it would perform.  I installed the upgraded EC-2 on Saturday.  Yea, it started on the third prop blade and ran quite well, although the Mixture knob was not at "12 O'clock", it ran very smooth.  Following the instructions in the manual, first thing I did was to adjust Mode 3 to compensate for my larger 60# injectors.  Now it was running really well in the upper rpm/map ranges.  A little adjusting of the lower addresses using Mode 1 & 9 and it was idling down around 1500 rpm.  (Keep in mind that this is a p-port motor.)  The exhaust tone at low idle is hard to describe...it is enough to send chills up your leg.  ;-0 

 

Sunday, after a some more tuning, I got it to where it would almost do 7000 rpm static.  (Keep in mind that Lockhart, TX is a small country town and this was Sunday morning.  You could probably hear me tuning my engine all over town.)  Confident that it would stay running, I decided it was time to fly.  It climbed out at 6700 rpm as smooth as could be.  There was a 5000' ceiling, so I couldn't climb too high, but the air was silky smooth.  I flew a couple of patterns, climbing as I circled.  At 3500 msl I headed east and did some tuning with Mode 9 at different MAP settings.  Up and down the scale, fine-tuning each address.  She was running like a fine Swiss watch, or to put it another way, like a rotary should.  

 

Issues: 

1)  MAP Readings - It appears that I may have a vacuum leak as the MAP at idle is reading 17.4".  Next trip to the airport I will double-check to make sure that I got both lines plugged into the EC-2 properly, and check for leaks elsewhere.  It is amazing that it idles as well as it does under these circumstances.  Note that rather than using a throttle body, I am using a slide-throttle which is located just a few inches from the intake ports.  So, the vacuum lines are plugged into the unused oil injection ports in the rotor housings (no oil injection pump).  Could this account for the unusual MAP readings?  I do have a plenum, but since it is open to the atmosphere, I can't measure MAP from there.  I think there are others that use this scheme with success. 

2) Performance - I seem to hit a speed wall at around 2000-2100 prop rpm.  I can set the prop higher and get a higher engine rpm, but the higher rpm doesn't translate into higher speeds.  The speed will gradually start bleeding off.  Not sure why this is happening.  Could be tuning, or intake/exhaust design, or just a characteristic of the M/T prop.  Or, maybe the engine isn't making enough horsepower to push the airframe through the air any faster.  It is annoying though, knowing that you have another 1500 rpm on tap but can't use it.

 

3) Alternator - the voltage reading on main alternator is low.  This is a new alternator which has been converted to external regulator.  I'll try adjusting the regulator (again). 

 

All in all, a very successful weekend.  As usual, more issues to sort out though. 

 

Mark S.

Lancair ES, N/A P-port 20B

Lockhart, TX

 

 

 

On Sun, Nov 14, 2010 at 11:20 PM, <hoursaway1@comcast.net> wrote:

Rodger that Doug, I just went through all the paperwork again to make sure all ducks in a row, then shot one of the ducks & had dinner, a sweet red wine marinade is the secret to good tender duck you know.  David.
----- Original Message -----
From: DLOMHEIM@aol.com
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Sunday, November 14, 2010 7:09:45 PM
Subject: [FlyRotary] Hey are those 304 Stainless staples...(from David)

Na...gotta be 321...don't you think David?!  I'm still hoping to read about some flying exploits from this weekend, from someone on the list!  Surely all our aviators weren't just sitting around watching football all day like us gimpy / DNIF guys!!!!   :)  

 

Mucho congrats on getting your project to the point of final inspection prior to first flight!  Take your time, be safe, and enjoy the moment!  Then post some pictures / data of the big event on the list!  :)    

 

Doug