 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
Terry Phillips
Joined: 11 Jan 2006
Posts: 346
Location: Corvallis, MT
|
 Posted: Sun Aug 16, 2009 5:43 am Post subject: ROP versus LOP...might be off-topic for some |
 |
|
Lynn
This is pretty exciting. I have been interested in LOP operation since I read John Deakin's series of articles--see
http://www.avweb.com/news/pelican/182179-1.html
and linked articles in the series.
Deakin's scenario was based on fuel injection, which did not appear to be an option for the Jabiru, so I had put LOP aside. I have some questions about the Rotec TBI.
It sounds like the Rotec is not true fuel injection, but rather is a throttle body injector. Is that correct? How is it different from the Ellison TBI's that I have seen advertised?
Deakin's articles suggest that very precise fuel injection is required for LOP operation to keep the fuel/air ratios consistent between the cylinders. What does the Rotec TBI do to achieve even distribution?
Have you seen any data for the Rotec TBI on the 3300?
If one can get the fuel savings that you have reported with the Rotec TBI, the payback is very attractive. I did a simple minded calculation using your data to produce the attached plot of payback miles and hours vs. fuel cost. This looks like great deal if there are no adverse effects on the engine. The numbers I calculated are here:
Gal/hr MPG TBI Cost
ROP 4.37 23.66 595
LOP 3.3 27.77
Payback
Fuel Price, $/gal Hours Miles
2.00 278 47559
3.00 185 31706
4.00 139 23780
5.00 111 19024
6.00 93 15853
7.00 79 13588
Terry
| Quote: | In a message dated 8/15/2009 1:21:33 P.M. Central Daylight Time,
lynnmatt(at)jps.net writes:
--> JabiruEngine-List message posted by: Lynn Matteson <lynnmatt(at)jps.net>
Over the last week, I've had some fun making some tests with my newly-
installed Rotec TBI-40 mixture-adjustable, carburetor-replacement
device on my Jabiru engine. I don't know whether two of these units
will work on a Rotax, so many of you might want to hit the delete key
right now.
For the most part, I was flying it LOP (lean-of-peak), but yesterday
I made a flight and decided that I would try ROP (rich-of-peak). In
flying LOP, the articles I've read say to keep the power requirements
low, and LOP will work and you won't burn the engine down. I was
amazed that this LOP thing even works at all, let alone work as well
as I've found that it seems too....I guess I'm still a bit of a
skeptic. After all, if going lean is a bad thing, how can going even
leaner be a good thing? I won't argue whether or not it's a good or
bad thing, and there are those of you that may not be able to do any
leaning at all, as I was until I got this unit.
Three days ago, I made two trips totaling 475 miles, using LOP
settings, and yesterday I made a 310-mile trip, using ROP settings. I
had flown the 475 miles leaning out the engine until peak EGT, then
leaning more until the engine was obviously low on power, and I
contentedly flew at this setting, watching the scenery crawl by.
Yesterday I decided to actually GO somewhere, and never mind the fuel
saving, I just wanted to get there, so I decided to try ROP.
Here are the average numbers from those trips:
LOP: 27.77 miles per gallon; 3.3 gallons per hour; 93.14
miles per hour
ROP: 23.66 miles per gallon; 4.37 gallons per hour; 103.3 miles per
hour
Altitudes on all of these flight were anywhere from 3000' MSL (with a
base of 1000') to 10,000 MSL, with throttle settings from 2600 rpm to
3050. Fuel flow as seen on the gauge, ranged from 2.5 gallons per
hour to 5.0 not including takeoffs, but including climbs.
So you can see from these figures (admittedly a low number of
samples) that it does pay to tweak the mixture, and even if flown
LOP, the speed is not too bad.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 737.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying |
Terry Phillips ZBAGer
ttp44~at~rkymtn.net
Corvallis MT
601XL/Jab 3300 s .. l .. o .. o .. w build kit - Tail, flaps, & ailerons are done; waiting on the wings
http://www.mykitlog.com/N47TP/
| | - The Matronics JabiruEngine-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?JabiruEngine-List |
|
| Description: |
|
Download |
| Filename: |
Payback_for_Rotec_TBI_running_LOP.pdf |
| Filesize: |
5.12 KB |
| Downloaded: |
407 Time(s) |
_________________
Terry Phillips
Corvallis, MT
ttp44<at>rkymtn.net
Zenith 601XL/Jab 3300 slow build kit - Tail feathers done; working on the wings. |
|
| Back to top |
|
 |
BobsV35B(at)AOL.COM
Guest
|
| Posted: Sun Aug 16, 2009 6:39 am Post subject: ROP versus LOP...might be off-topic for some |
|
|
Good Morning Terry,
Having the Continental style of intake injection to each cylinder makes it a lot easier to make corrections if bad distribution is found to exist, but some carbureted engines do have good distribution and can benefit from lean side operations.
A very simple way to check distribution is to lean the engine and observe it's response. It is best if you have an EGT and CHT on every cylinder combined with a good electronic fuel flow device, but a check can be made with none of the above.
Just set your normal cruise power at an altitude where your normally aspirated engine cannot exceed seventy percent power. (Ya gotta do this in smooth, stable air.) Then start to slowly lean the engine starting from full rich. You should note a small increase in RPM as the mixture approaches the best power point. When the RPM is the highest, that IS best power. Continue to lean and see what happens. If you can get a hundred or so drop in RPM before the engine gets rough, the distribution is pretty good. Richen back to best power (Highest RPM) then lean for a fifty RPM drop and you will be very close to best BSFC. As an aside, that is how Lindbergh did it on his flight from New York to Paris.
Back to the beginning. Let's suppose that the engine gets rough before you note much if any increase in RPM. -- That tells us that the distribution is abominable!
If the engine is equipped with EGT indications for every cylinder and if you have a good fuel flow unit, you can evaluate the distribution by doing the following.
Once again, start out at seven thousand feet. Lean until a drop in fuel flow is noted. Write down the fuel flow, the CHT and the EGT of each cylinder. Drop the fuel flow another tenth of a gallon (maybe two or three tenths for higher power engines) and write down the numbers shown. Continue doing so until the engine gets so rough you can't take it any more. Look at the data and note the point at which each cylinder's EGT peaks. If they all peak at about the same fuel flow, the distribution is great. That is what would happen for the engine I described earlier that had at least a one hundred drop in RPM before the onset of roughness.
If the peak EGTs occurred with a substantially different fuel flow between cylinders, the distribution stinks!
How much fuel flow difference is good and how much is bad? On an engine that cruises at fourteen GPH, three tenths of a gallon difference between the first to go and the last to go is considered excellent and a half gallon is good. A gallon and a half to two gallons is abominable.
For lower power engines, use lower equivalent differences.
My first example assumes the use of a fixed pitch propellor. If the airplane has a constant speed propellor (governor controlled) you can use airspeed increase and decrease instead of RPM to find peak power.
I stole this idea of using the all cylinder engine monitor from the GAMI folks at Ada Oklahoma. They are the manufacturers of the GAMIjectors that are used in many Continental and Lycoming fuel injected engines and call it the GAMI Lean Check.
Before GAMI came on the scene and devised the use of an all cylinder monitor to find out which cylinder needs adjustment, all we had to work with was the RPM or airspeed method and we just had to keep trying things to see what would make the distribution better. Very hit and miss. The ready availability of good engine instrumentation has made the quest for good distribution much easier.
Changing the angle of the inlet divider vanes can make a major change on our Jabiru engines. I am sure the participants of this list have many good thoughts on what sort of tweaking will be productive.
Once again, having the data on paper tells us where to start!
Any help at all?
Happy Skies,
Old Bob
In a message dated 8/16/2009 8:44:31 A.M. Central Daylight Time, ttp44(at)rkymtn.net writes:
| Quote: | Lynn
This is pretty exciting. I have been interested in LOP operation since I read John Deakin's series of articles--see
http://www.avweb.com/news/pelican/182179-1.html
and linked articles in the series.
Deakin's scenario was based on fuel injection, which did not appear to be an option for the Jabiru, so I had put LOP aside. I have some questions about the Rotec TBI.
It sounds like the Rotec is not true fuel injection, but rather is a throttle body injector. Is that correct? How is it different from the Ellison TBI's that I have seen advertised?
Deakin's articles suggest that very precise fuel injection is required for LOP operation to keep the fuel/air ratios consistent between the cylinders. What does the Rotec TBI do to achieve even distribution?
Have you seen any data for the Rotec TBI on the 3300?
If one can get the fuel savings that you have reported with the Rotec TBI, the payback is very attractive. I did a simple minded calculation using your data to produce the attached plot of payback miles and hours vs. fuel cost. This looks like great deal if there are no adverse effects on the engine. The numbers I calculated are here:
Gal/hr MPG TBI Cost
ROP 4.37 23.66 595
LOP 3.3 27.77
Payback
Fuel Price, $/gal Hours Miles
2.00 278 47559
3.00 185 31706
4.00 139 23780
5.00 111 19024
6.00 93 15853
7.00 79 13588
Terry
| Quote: | In a message dated 8/15/2009 1:21:33 P.M. Central Daylight Time,
lynnmatt(at)jps.net writes:
--> JabiruEngine-List message posted by: Lynn Matteson <lynnmatt(at)jps.net>
Over the last week, I've had some fun making some tests with my newly-
installed Rotec TBI-40 mixture-adjustable, carburetor-replacement
device on my Jabiru engine. I don't know whether two of these units
will work on a Rotax, so many of you might want to hit the delete key
right now.
For the most part, I was flying it LOP (lean-of-peak), but yesterday
I made a flight and decided that I would try ROP (rich-of-peak). In
flying LOP, the articles I've read say to keep the power requirements
low, and LOP will work and you won't burn the engine down. I was
amazed that this LOP thing even works at all, let alone work as well
as I've found that it seems too....I guess I'm still a bit of a
skeptic. After all, if going lean is a bad thing, how can going even
leaner be a good thing? I won't argue whether or not it's a good or
bad thing, and there are those of you that may not be able to do any
leaning at all, as I was until I got this unit.
Three days ago, I made two trips totaling 475 miles, using LOP
settings, and yesterday I made a 310-mile trip, using ROP settings. I
had flown the 475 miles leaning out the engine until peak EGT, then
leaning more until the engine was obviously low on power, and I
contentedly flew at this setting, watching the scenery crawl by.
Yesterday I decided to actually GO somewhere, and never mind the fuel
saving, I just wanted to get there, so I decided to try ROP.
Here are the average numbers from those trips:
LOP: 27.77 miles per gallon; 3.3 gallons per hour; 93.14
miles per hour
ROP: 23.66 miles per gallon; 4.37 gallons per hour; 103.3 miles per
hour
Altitudes on all of these flight were anywhere from 3000' MSL (with a
base of 1000') to 10,000 MSL, with throttle settings from 2600 rpm to
3050. Fuel flow as seen on the gauge, ranged from 2.5 gallons per
hour to 5.0 not including takeoffs, but including climbs.
So you can see from these figures (admittedly a low number of
samples) that it does pay to tweak the mixture, and even if flown
LOP, the speed is not too bad.
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 737.3 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying |
Terry Phillips ZBAGer
ttp44~at~rkymtn.net
Corvallis MT
601XL/Jab 3300 s .. l .. o .. o .. w build kit - Tail, flaps, & ailerons are done; waiting on the wings
http://www.mykitlog.com/N47TP/ |
| | - The Matronics JabiruEngine-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?JabiruEngine-List |
|
|
|
| Back to top |
|
|
Lynn Matteson
Joined: 10 Jan 2006
Posts: 2778
Location: Grass Lake, Michigan
|
| Posted: Sun Aug 16, 2009 8:34 am Post subject: ROP versus LOP...might be off-topic for some |
|
|
I've been reading the Deakin's articles just lately, and have a few
more to go....thanks for the address.
The Rotec is NOT true injection with nozzles at each intake tube, but
throttle body injection as you guessed. The Rotec representative
(he's way more than just a rep) that I bought mine from at Oshkosh
made no bones about virtually "stealing" the fuel discharge tube idea
from the Ellison. I think one main difference is price, but more than
that, the Ellison has...according to pictures I've seen....a
diaphragm or regulator built right into the body, whereas Rotec's
regulator is separate. Apart from that, they look pretty much
identical. Now before anybody climbs all over me for that statement,
I will say that I HAVE the Rotec TBI, and have not even SEEN the
Ellison other than in pictures, so my comparison is limited.
The Rotec TBI does not address even distribution per se, in probably
anything outside of their application with their engines. But I have
found that the distribution is pretty even, although the EGT numbers,
and the CHT numbers DO vary from cylinder to cylinder....different
loads, different rpm's, etc....but are pretty close together. I have
seen a CHT spread of 1 degree F., and EGT's within 34 degrees of one
another. I posted some numbers last week on one of the groups, can't
recall which, where the comparison between the Bing carb and the TBI
were made. The Bing's closest EGT spread averaged 89° F, and the
TBI's was 84. The Bing CHT average spread was 44, while the TBI was
21, and the fuel flow with the Bing averaged 4.27 gph, and the TBI
showed an average of 3.25. These figures were gathered over about 25
samples on each device.
I have all 4 cylinders monitored via my Grand Rapids EIS, for EGT and
CHT, and fuel flow with a Northstar F210. That's about as close as I
can get to doing anything about "even distribution".....monitor each
cylinder, and change a setting if it looks like I'm getting too hot
somewhere. So far this hasn't been a problem.
I haven't seen any data on the 3300, but a few folks (3300 drivers)
have emailed me personally, and have them on order....one guy was
even waiting on the porch for the Big Brown Truck to arrive with
his. : )
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 739.7 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Aug 16, 2009, at 9:29 AM, Terry Phillips wrote:
| Quote: | Lynn
This is pretty exciting. I have been interested in LOP operation
since I read John Deakin's series of articles--see
http://www.avweb.com/news/pelican/182179-1.html
and linked articles in the series.
Deakin's scenario was based on fuel injection, which did not appear
to be an option for the Jabiru, so I had put LOP aside. I have some
questions about the Rotec TBI.
It sounds like the Rotec is not true fuel injection, but rather is
a throttle body injector. Is that correct? How is it different from
the Ellison TBI's that I have seen advertised?
Deakin's articles suggest that very precise fuel injection is
required for LOP operation to keep the fuel/air ratios consistent
between the cylinders. What does the Rotec TBI do to achieve even
distribution?
Have you seen any data for the Rotec TBI on the 3300?
If one can get the fuel savings that you have reported with the
Rotec TBI, the payback is very attractive. I did a simple minded
calculation using your data to produce the attached plot of payback
miles and hours vs. fuel cost. This looks like great deal if there
are no adverse effects on the engine. The numbers I calculated are
here:
Gal/hr MPG TBI Cost
ROP 4.37 23.66 595
LOP 3.3 27.77
Payback
Fuel Price, $/gal Hours Miles
2.00 278 47559
3.00 185 31706
4.00 139 23780
5.00 111 19024
6.00 93 15853
7.00 79 13588
Terry
> In a message dated 8/15/2009 1:21:33 P.M. Central Daylight Time,
> lynnmatt(at)jps.net writes:
>
>
> <lynnmatt(at)jps.net>
>
> Over the last week, I've had some fun making some tests with my
> newly-
> installed Rotec TBI-40 mixture-adjustable, carburetor-replacement
> device on my Jabiru engine. I don't know whether two of these units
> will work on a Rotax, so many of you might want to hit the delete
> key
> right now.
>
> For the most part, I was flying it LOP (lean-of-peak), but yesterday
> I made a flight and decided that I would try ROP (rich-of-peak). In
> flying LOP, the articles I've read say to keep the power
> requirements
> low, and LOP will work and you won't burn the engine down. I was
> amazed that this LOP thing even works at all, let alone work as well
> as I've found that it seems too....I guess I'm still a bit of a
> skeptic. After all, if going lean is a bad thing, how can going even
> leaner be a good thing? I won't argue whether or not it's a good or
> bad thing, and there are those of you that may not be able to do any
> leaning at all, as I was until I got this unit.
> Three days ago, I made two trips totaling 475 miles, using LOP
> settings, and yesterday I made a 310-mile trip, using ROP
> settings. I
> had flown the 475 miles leaning out the engine until peak EGT, then
> leaning more until the engine was obviously low on power, and I
> contentedly flew at this setting, watching the scenery crawl by.
> Yesterday I decided to actually GO somewhere, and never mind the
> fuel
> saving, I just wanted to get there, so I decided to try ROP.
> Here are the average numbers from those trips:
>
> LOP: 27.77 miles per gallon; 3.3 gallons per hour; 93.14
> miles per hour
> ROP: 23.66 miles per gallon; 4.37 gallons per hour; 103.3
> miles per
>
> hour
>
> Altitudes on all of these flight were anywhere from 3000' MSL
> (with a
> base of 1000') to 10,000 MSL, with throttle settings from 2600
> rpm to
> 3050. Fuel flow as seen on the gauge, ranged from 2.5 gallons per
> hour to 5.0 not including takeoffs, but including climbs.
>
> So you can see from these figures (admittedly a low number of
> samples) that it does pay to tweak the mixture, and even if flown
> LOP, the speed is not too bad.
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 737.3 hrs
> Sensenich 62"x46" Wood prop
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying
Terry Phillips ZBAGer
ttp44~at~rkymtn.net
Corvallis MT
601XL/Jab 3300 s .. l .. o .. o .. w build kit - Tail, flaps, &
ailerons are done; waiting on the wings
http://www.mykitlog.com/N47TP/
<Payback for Rotec TBI running LOP.pdf>
|
| | - The Matronics JabiruEngine-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?JabiruEngine-List |
|
_________________
Lynn
Kitfox IV-Jabiru 2200
N369LM |
|
| Back to top |
|
|
BobsV35B(at)AOL.COM
Guest
|
| Posted: Sun Aug 16, 2009 9:09 am Post subject: ROP versus LOP...might be off-topic for some |
|
|
Good Morning Again Lynn,
Trust me, the actual numbers that you see on your EGTs are not particularly significant.
The main thing is how close to the same fuel flow that the PEAK EGT occurs on each cylinder.
Very small differences in the location of a probe can make major differences in the EGT temps, but running a GAMI Lean Check will tell you exactly how even your distribution really is. Well worth the time it takes to perform the check!
Happy Skies,
Old Bob
In a message dated 8/16/2009 11:35:00 A.M. Central Daylight Time, lynnmatt(at)jps.net writes:
| Quote: | --> JabiruEngine-List message posted by: Lynn Matteson <lynnmatt(at)jps.net>
I've been reading the Deakin's articles just lately, and have a few
more to go....thanks for the address.
The Rotec is NOT true injection with nozzles at each intake tube, but
throttle body injection as you guessed. The Rotec representative
(he's way more than just a rep) that I bought mine from at Oshkosh
made no bones about virtually "stealing" the fuel discharge tube idea
from the Ellison. I think one main difference is price, but more than
that, the Ellison has...according to pictures I've seen....a
diaphragm or regulator built right into the body, whereas Rotec's
regulator is separate. Apart from that, they look pretty much
identical. Now before anybody climbs all over me for that statement,
I will say that I HAVE the Rotec TBI, and have not even SEEN the
Ellison other than in pictures, so my comparison is limited.
The Rotec TBI does not address even distribution per se, in probably
anything outside of their application with their engines. But I have
found that the distribution is pretty even, although the EGT numbers,
and the CHT numbers DO vary from cylinder to cylinder....different
loads, different rpm's, etc....but are pretty close together. I have
seen a CHT spread of 1 degree F., and EGT's within 34 degrees of one
another. I posted some numbers last week on one of the groups, can't
recall which, where the comparison between the Bing carb and the TBI
were made. The Bing's closest EGT spread averaged 89° F, and the
TBI's was 84. The Bing CHT average spread was 44, while the TBI was
21, and the fuel flow with the Bing averaged 4.27 gph, and the TBI
showed an average of 3.25. These figures were gathered over about 25
samples on each device.
I have all 4 cylinders monitored via my Grand Rapids EIS, for EGT and
CHT, and fuel flow with a Northstar F210. That's about as close as I
can get to doing anything about "even distribution".....monitor each
cylinder, and change a setting if it looks like I'm getting too hot
somewhere. So far this hasn't been a problem.
I haven't seen any data on the 3300, but a few folks (3300 drivers)
have emailed me personally, and have them on order....one guy was
even waiting on the porch for the Big Brown Truck to arrive with
his. : )
Lynn Matteson
Kitfox IV Speedster, taildragger
Jabiru 2200, #2062, 739.7 hrs
Sensenich 62"x46" Wood prop
Electroair direct-fire ignition system
Rotec TBI-40 injection
Status: flying
On Aug 16, 2009, at 9:29 AM, Terry Phillips wrote:
| Quote: | Lynn
This is pretty exciting. I have been interested in LOP operation
since I read John Deakin's series of articles--see
http://www.avweb.com/news/pelican/182179-1.html
and linked articles in the series.
Deakin's scenario was based on fuel injection, which did not appear
to be an option for the Jabiru, so I had put LOP aside. I have some
questions about the Rotec TBI.
It sounds like the Rotec is not true fuel injection, but rather is
a throttle body injector. Is that correct? How is it different from
the Ellison TBI's that I have seen advertised?
Deakin's articles suggest that very precise fuel injection is
required for LOP operation to keep the fuel/air ratios consistent
between the cylinders. What does the Rotec TBI do to achieve even
distribution?
Have you seen any data for the Rotec TBI on the 3300?
If one can get the fuel savings that you have reported with the
Rotec TBI, the payback is very attractive. I did a simple minded
calculation using your data to produce the attached plot of payback
miles and hours vs. fuel cost. This looks like great deal if there
are no adverse effects on the engine. The numbers I calculated are
here:
Gal/hr MPG TBI Cost
ROP 4.37 23.66 595
LOP 3.3 27.77
Payback
Fuel Price, $/gal Hours Miles
2.00 278 47559
3.00 185 31706
4.00 139 23780
5.00 111 19024
6.00 93 15853
7.00 79 13588
Terry
> In a message dated 8/15/2009 1:21:33 P.M. Central Daylight Time,
> lynnmatt(at)jps.net writes:
>
> --> JabiruEngine-List message posted by: Lynn Matteson
> <lynnmatt(at)jps.net>
>
> Over the last week, I've had some fun making some tests with my
> newly-
> installed Rotec TBI-40 mixture-adjustable, carburetor-replacement
> device on my Jabiru engine. I don't know whether two of these units
> will work on a Rotax, so many of you might want to hit the delete
> key
> right now.
>
> For the most part, I was flying it LOP (lean-of-peak), but yesterday
> I made a flight and decided that I would try ROP (rich-of-peak). In
> flying LOP, the articles I've read say to keep the power
> requirements
> low, and LOP will work and you won't burn the engine down. I was
> amazed that this LOP thing even works at all, let alone work as well
> as I've found that it seems too....I guess I'm still a bit of a
> skeptic. After all, if going lean is a bad thing, how can going even
> leaner be a good thing? I won't argue whether or not it's a good or
> bad thing, and there are those of you that may not be able to do any
> leaning at all, as I was until I got this unit.
> Three days ago, I made two trips totaling 475 miles, using LOP
> settings, and yesterday I made a 310-mile trip, using ROP
> settings. I
> had flown the 475 miles leaning out the engine until peak EGT, then
> leaning more until the engine was obviously low on power, and I
> contentedly flew at this setting, watching the scenery crawl by.
> Yesterday I decided to actually GO somewhere, and never mind the
> fuel
> saving, I just wanted to get there, so I decided to try ROP.
> Here are the average numbers from those trips:
>
> LOP: 27.77 miles per gallon; 3.3 gallons per hour; 93.14
> miles per hour
> ROP: 23.66 miles per gallon; 4.37 gallons per hour; 103.3
> miles per
>
> hour
>
> Altitudes on all of these flight were anywhere from 3000' MSL
> (with a
> base of 1000') to 10,000 MSL, with throttle settings from 2600
> rpm to
> 3050. Fuel flow as seen on the gauge, ranged from 2.5 gallons per
> hour to 5.0 not including takeoffs, but including climbs.
>
> So you can see from these figures (admittedly a low number of
> samples) that it does pay to tweak the mixture, and even if flown
> LOP, the speed is not too bad.
>
> Lynn Matteson
> Kitfox IV Speedster, taildragger
> Jabiru 2200, #2062, 737.3 hrs
> Sensenich 62"x46" Wood prop
> Electroair direct-fire ignition system
> Rotec TBI-40 injection
> Status: flying
Terry Phillips ZBAGer
ttp44~at~rkymtn.net
Corvallis MT
601XL/Jab 3300 s .. l .. o .. o .. w build kit - Tail, flaps, &
ailerons are done; waiting on the wings
http://www.mykitlog.com/N47TP/
<Payback for Rotec TBI running ========================= = Use utilities Day ================================================ - MATRONICS WEB FORUMS ================================================ - List Contribution Web Site sp; ===================================================
|
|
[quote][b]
| | - The Matronics JabiruEngine-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?JabiruEngine-List |
|
|
|
| Back to top |
|
|
Terry Phillips
Joined: 11 Jan 2006
Posts: 346
Location: Corvallis, MT
|
| Posted: Tue Aug 18, 2009 5:18 am Post subject: Re: ROP versus LOP...might be off-topic for some |
|
|
Lynn & Bob
Thank you for the detailed resonses. The Rotec TBI sounds like a very promising development for the Jabiru. I think there is much to be gained (or fuel saved) by LOP operation. I will look forward to future reports.
Terry
do not archive
| | - The Matronics JabiruEngine-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?JabiruEngine-List |
|
_________________
Terry Phillips
Corvallis, MT
ttp44<at>rkymtn.net
Zenith 601XL/Jab 3300 slow build kit - Tail feathers done; working on the wings. |
|
| Back to top |
|
|
|
|
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 can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
