|
-
POSTING RULES

-
Donate yearly (please).
-
Advertise in here!
-
Today's Posts
|
Insert Pics
|

01-27-2016, 08:13 PM
|
 |
|
|
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
|
|
Magic
Here's what we're up against with typical vertical induction Lycomings:
Bad pairings, unequal shapes, small plenum volume and unequal runner lengths.
A recent test flight on a four cylinder with the fuel trim option had one cylinder at +2% and another at -9% to get all to peak at the same time. Was able to run at 200F LOP with uber smoothness.
Hopefully have more details soon.
|

01-29-2016, 01:31 PM
|
|
|
|
Join Date: Jun 2006
Posts: 316
|
|
Not magic, just facts
Of course that intake manifold was designed for a carburetor to be wet flowed. But even then, the most we see on most RV-10?s running that sump with our fuel injection (or Precision) is 1.5 to 2.5% total change in flow to get 0.2 GPH spread. On four cylinder up draft sumps it?s usually less than 1% to 1.5%. The Superior front sump is better. But the exhaust system plays a big role in the air distribution also. So if the engine you were working had an 11% (+2% to -9%) spread in airflow between cylinders then I would say that the engine was really screwed up. Or perhaps the fuel distribution was not equal, to begin with.
|

01-29-2016, 02:22 PM
|
 |
|
|
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
|
|
Quote:
Originally Posted by Don at Airflow
Of course that intake manifold was designed for a carburetor to be wet flowed. But even then, the most we see on most RV-10’s running that sump with our fuel injection (or Precision) is 1.5 to 2.5% total change in flow to get 0.2 GPH spread. On four cylinder up draft sumps it’s usually less than 1% to 1.5%. The Superior front sump is better. But the exhaust system plays a big role in the air distribution also. So if the engine you were working had an 11% (+2% to -9%) spread in airflow between cylinders then I would say that the engine was really screwed up. Or perhaps the fuel distribution was not equal, to begin with.
|
I'd use the word "designed" here loosely. Lycoming simply joined everything together so it fit. Huge GAMI spreads are not uncommon on Lycoming engines as delivered with a variety of sumps. I'd look towards the transverse, Sky Dynamics plenum for something that's designed properly. One client has that fitted along with Lycon flow matched heads and equal length exhaust. Will be interesting to see what the basic spread is on that one.
The owner can comment. As far as I know the engine is fresh, not sure what exhaust he has on it. He changed to a Superior sump and it changed nothing in his case. Swapped injectors to different holes and that changed nothing. Clearly he has a bad case of mixture distribution which is why he wanted it fixed. This technology brings the spread to 0 at any power setting/ rpm- from the cockpit, in 45 seconds. That's as close to magic as things get in the Lycoming world. Trying to bring these engines into the 21st century with modern electronic controls and features. I don't design manifolds for Lycomings, just provide the tools for our customers to fix any imbalances they have.
Last edited by rv6ejguy : 01-30-2016 at 07:57 PM.
|

01-29-2016, 06:46 PM
|
 |
|
|
Join Date: Oct 2005
Location: 08A
Posts: 9,500
|
|
The ability to trim individual injectors with a keyboard entry is an excellent feature. My compliments to Ross and the SDS team for getting the job done so quickly. Way to go!
__________________
Dan Horton
RV-8 SS
Barrett IO-390
|

01-30-2016, 09:45 AM
|
 |
|
|
Join Date: Mar 2005
Location: Calgary, Canada
Posts: 5,766
|
|
Quote:
Originally Posted by DanH
The ability to trim individual injectors with a keyboard entry is an excellent feature. My compliments to Ross and the SDS team for getting the job done so quickly. Way to go!
|
Thanks Dan. Appreciate the comment. My hardware/ software guy is amazing and worked hard on making this seamless and simple which is our trademark. Working on a couple more software releases to further improve the product for the aviation market- reducing mechanical devices and dependency.Will be testing and validating those this week.
There will also be some new fuel and ignition hardware for 540s released by weeks end.
Last edited by rv6ejguy : 07-04-2016 at 04:45 PM.
Reason: typo
|

01-30-2016, 01:46 PM
|
 |
|
|
Join Date: Jan 2012
Location: Friendswood, TX
Posts: 193
|
|
Quote:
Originally Posted by rv6ejguy
The owner can comment. As far as I know the engine is fresh, not sure what exhaust he has on it. He changed to a Superior sump and it changed nothing in his case. Swapped injectors to different holes and that changed nothing. Clearly he has a bad scenario case which is why he wanted it fixed. This technology brings the spread to 0 at any power setting/ rpm- from the cockpit, in 45 seconds. That's as close to magic as things get in the Lycoming world. Trying to bring these engines into the 21st century with modern electronic controls and features. I don't design manifolds for Lycomings, just provide the tools for our customers to fix any imbalances they have.
|
As Ross stated, yes I did swap the sump from Titan (ECI) to Superior with no noticeable changes, so the sump swap was a huge waste of time and money. As can be seen in my screen shots, the engine is a new Titan IOX370 (100 hours) running standard Vetterman crossover exhaust.
With the help from Rusty Crawford, this modification to my existing EFII setup only took a few hours and was relatively simple.
As the pics below show, after 45 seconds of tuning, I went from a GAMI spread of 1.3 to a GAMI spread of 0. Engine runs smooth all the way to about 200 deg LOP where as before I could only get to about 80 deg LOP since before when 80 LOP, cylinders 1/3 were at about 200 deg LOP.
Another benefit is now I have a clear picture of which cylinders I need to focus on for better cooling. Before I would have thought it was 1/3, but actually I need to work on 2/4 first.
Plus, now I am getting more average power with less wasted fuel since all of the cylinders are making optimum power.
Amazing work by the SDS team and Rusty Crawford. This has been many years in the making! I feel so lucky to have gotten to try this out for them!!!
Picture 1 - Leaning to LOP before the tuning - GAMI approx 1.3, notice large EGT spread, also notice 1/3 had highest CHT's when ROP, but coldest when LOP
Picture 2 - Leaning to LOP after the tuning - GAMI 0, notice how 2/4 always have hottest CHT's now.
Picture 3 - ROP climb before tuning - Large EGT spread
Picture 4 - ROP climb after tuning
Picture 1
Picture 2
Picture 3
Picture 4

__________________
RV-7 Flying Since March 2015
N412HC
Titan IOX-370
SDS Tunable Injectors
EFII Dual Ignition and Fuel Injection
Garmin G3X Touch
Whirl Wind 200RV Prop
7XS0 Polly Ranch Airpark, Friendswood, TX
|

01-30-2016, 02:15 PM
|
 |
|
|
Join Date: Jan 2012
Location: Friendswood, TX
Posts: 193
|
|
__________________
RV-7 Flying Since March 2015
N412HC
Titan IOX-370
SDS Tunable Injectors
EFII Dual Ignition and Fuel Injection
Garmin G3X Touch
Whirl Wind 200RV Prop
7XS0 Polly Ranch Airpark, Friendswood, TX
|

01-30-2016, 06:38 PM
|
 |
|
|
Join Date: Jul 2009
Location: Mojave
Posts: 4,652
|
|
Since the lack of plenum volume on the updraft sumps seems to be one of the issues, I wonder if instead of the typically seen 90 degree elbow adapter used to convert to a forward facing servo, if you could instead construct a large volume airbox and attach the servo to the front of that? Im thinking a 10 inch diameter, x 3 inch deep cylinder with a servo mount right in front - essentially a very large volume "elbow". Clearly, it would be a partial solution (if it worked at all), but it would be pretty easy to do.
__________________
WARNING! Incorrect design and/or fabrication of aircraft and/or components may result in injury or death. Information presented in this post is based on my own experience - Reader has sole responsibility for determining accuracy or suitability for use.
Michael Robinson
______________
Harmon Rocket II -SDS EFI
RV-8 - SDS CPI
1940 Taylorcraft BL-65
1984 L39C
|

01-30-2016, 08:10 PM
|
 |
|
|
Join Date: Dec 2012
Location: Brooksville, MS
Posts: 745
|
|
Quote:
Originally Posted by Toobuilder
Since the lack of plenum volume on the updraft sumps seems to be one of the issues, I wonder if instead of the typically seen 90 degree elbow adapter used to convert to a forward facing servo, if you could instead construct a large volume airbox and attach the servo to the front of that? Im thinking a 10 inch diameter, x 3 inch deep cylinder with a servo mount right in front - essentially a very large volume "elbow". Clearly, it would be a partial solution (if it worked at all), but it would be pretty easy to do.
|
Would you design the system with a filter after the servo?
__________________
Weasel
RV-4 715hr Sold 
RV-10 "School Bus" -   +1600hr counting
Fisher Classic Cassler Power VW sold
RV-10 N7631T 820hr Sold
RV-8 700+hrs
Carbon Cub 200 hr Sold
One-Off Super Cub 100 hr
SERFI AWARDS
http://weaselrv10.blogspot.com/
|

01-30-2016, 09:21 PM
|
 |
|
|
Join Date: Jan 2012
Location: Friendswood, TX
Posts: 193
|
|
Quote:
Originally Posted by Toobuilder
Since the lack of plenum volume on the updraft sumps seems to be one of the issues, I wonder if instead of the typically seen 90 degree elbow adapter used to convert to a forward facing servo, if you could instead construct a large volume airbox and attach the servo to the front of that? Im thinking a 10 inch diameter, x 3 inch deep cylinder with a servo mount right in front - essentially a very large volume "elbow". Clearly, it would be a partial solution (if it worked at all), but it would be pretty easy to do.
|
Interesting idea, but I don't think that would do anything to balance uneven airflow. It may increase the airflow overall, but the imbalance would still be there. By tuning the injectors, the imbalance is a moot point now.
__________________
RV-7 Flying Since March 2015
N412HC
Titan IOX-370
SDS Tunable Injectors
EFII Dual Ignition and Fuel Injection
Garmin G3X Touch
Whirl Wind 200RV Prop
7XS0 Polly Ranch Airpark, Friendswood, TX
|
| Thread Tools |
Search this Thread |
|
|
|
| Display Modes |
Linear Mode
|
Posting Rules
|
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
HTML code is Off
|
|
|
All times are GMT -6. The time now is 05:15 AM.
|