Matronics Email Lists Forum Index Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
 
 Get Email Distribution Too!Get Email Distribution Too!    FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups   RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 

Rotec test flight

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Lightning-List
View previous topic :: View next topic  
Author Message
Bill Strahan



Joined: 20 Aug 2008
Posts: 145

PostPosted: Tue Feb 16, 2010 5:29 pm    Post subject: Rotec test flight Reply with quote

I am editing this post as it was pointed out to me that my frustration could be interpreted as an indictment of the Rotec TBI rather than a longer term frustration in getting the Jabiru to run the way I want it to, specifically with good fuel distribution at full power at all altitudes at which I fly.

I have one more fight on the Rotec now, and did so with the normal induction system disconnected and a K&N air filter in place instead. This allowed me to remove the scat tubing and induction system as a possible problem area and focus on the Rotec.

Results were better, and it mid-power settings I am getting the same speed/rpm I got with the Bing on slightly lower fuel burns. I already had the Hacman installed on the Bing, so for the same 120 knot cruise I was down a nother couple of tenths of a gallon.

That was encouraging.

Full power settings are suspiciously similar to the Bing, and I expect that I'll get to keep playing to find out where to go next.

With the K&N RU-0620 filter in place directly on the Rotec I don't have carb heat so I am somewhat limited in the weather conditions I will attempt to fly in to gather data. If that is not a concern for you, and you are having any induction issues, google that K&N part number and see if it might work for you as well. At least you can verify the induction system up to the carb, one way or the other.

I'll keep you guys updated. The Rotec guys are emailing with me to help me start the fine tuning process so I hope to have more news within the week.


- The Matronics Lightning-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Lightning-List


Last edited by Bill Strahan on Mon Mar 01, 2010 11:36 am; edited 1 time in total
Back to top
View user's profile Send private message
N1BZRich(at)aol.com
Guest





PostPosted: Tue Feb 16, 2010 7:54 pm    Post subject: Rotec test flight Reply with quote

Bill,
Thanks for the run down. Although the initial flight with the Rotec didn't result in all the total improvements you were aiming for, at least you got a successful data gathering flight. And that's what it is all about at this early stage of experimenting. Thank goodness "experimental" allows us to do that. Heck, if it was easy, everybody would be doing it.  Keep up the good work and thanks for keeping all of us in the loop.
Blue Skies,
Buz

In a message dated 2/16/2010 8:33:11 P.M. Eastern Standard Time, bill(at)gdsx.com writes:
Quote:
--> Lightning-List message posted by: "Bill Strahan" <bill(at)gdsx.com>

Hmmm. Well, I had high expectations and truly poor outcome. Hard not to be a bit frustrated.

Engine fired right up and idled well, if a little high at about 950 rpm. Everything warmed up and the runup went well. On takeoff, it felt okay, but it's hard to really feel the engine smoothness (or lack thereof) when the tires are rolling.

Once airborne, it was apparent that the engine was shaking a bit. But by then I was far enough along that I decided to continue climbing and see what transpired.

Sure enough, the EGTs were pretty uneven, but once I throttled back a bit the engine smoothed out. That was good enough for me to continue climbing, so I took it up to 5500' to check things out.

At full throttle, the EGTs spread out by more than 200 degrees and the engine runs very rough. As I pull the throttle back some, the spread decreases some and the engine smooths out and RPMs increase. I would get rough running and 2800 rpm and then smooth and 2850-2900 at a slightly LOWER power setting.

Sigh. It's similar to what the Bing did, but different. It's also not the same cylinders that run too lean and too rich. Double sigh.

I took it on up to 14,500 to see how it ran there and I was getting about 140 MPH on 4.0 gph. Leaning worked well, but the lean cylinders would peak and drop long before the other cylinders.

Similar to the bing, the EGT temps were closest at very low throttle setting, like 3.5-4.0 gph.

Having all that altitude to play with, I explored the speed a bit on the way back.  I very slowly increased speed in 5 mph increments up to 195 knots true, and 165 indicated. That at least was the enjoyable part.

Next I called the tower and when I hit the PTT I got this very loud squeal in my headset. Thought that was strange, it's worked perfectly since I had the plane, but suddenly the radio has a problem.

The tower could hear me over the squeal, but it was incredibly annoying and made communication difficult.

So with the engine running overall WORSE than it had with the Bing, and the radio now giving me problems, when the engine quit on final I just figured it was par for the course.

Triple sigh.

As usual, I was setup to make the runway regardless, touching down about 500' down. I felt bad for the big twin turboprop that had to go around because I couldn't get it started soon enough to get past the hold short line. He probably burned more fuel in going around than I had in my 1.3 hour flight.

So, nothing good to report yet. I have some ideas as to what might cause the uneven distribution of fuel, but it will have to wait until next week to play around with it. As to the radio, I have no idea. I'm hoping the avionics fairies come and fix it while I'm out.


Read this topic online here:

http://forums.matronics.com/viewtopic.php?p=286702#286702===============================================
_-= Use the ties Day ================================================ - MATRONICS WEB FORUMS ================================================ - List Contribution Web Site sp;   ===================================================


[quote][b]


- The Matronics Lightning-List Email Forum -
 

Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:

http://www.matronics.com/Navigator?Lightning-List
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> Lightning-List All times are GMT - 8 Hours
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You cannot download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group