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  #1  
Old 06-05-2017, 12:24 PM
ALMARTON ALMARTON is offline
 
Join Date: Mar 2010
Location: BRAZIL
Posts: 110
Unhappy POOR PERFORMANCE SEEKING ADVICE

SEEKING ADVICE FROM RV COMMUNITY

I've got a RV7A in Brazil IO360 with Hartzell CS propeller only 140 hours from new Very well built but needing some adjusts I guess.

Guess that because currently it is doing only 151kts TAS (2400rpm) at 65% power at @ 8000 ft OR... 155 kts at 75% (2500 rpm -same altitude conditions). And it does that consuming a lot of gas... about 12 gals at 65% or 13,5 gals at 75% power! - best power ROP adjust -

I suspect the Fuel Injection System (AVSTAR) has to be regulated and the noozles clean because it is too rich and there is a difference in CHT and EGT to one cylinder, it also gets very rough on LEAN.

Another guess is that the Hartzell propeller may not be well set (angles of the blades not correct set in installation).

It does reach the 2700 rpm in take off run, and the correct MAP pressure (to be known - 1 psi maninfold less than static manifold of the day - QFE - )

I did purchase de aircraft ready , all NEW and tested, so I do not have knowledge of the assembling issues affecting speed and consumption neither adjusts I have to make to increase cruise speed and decrease fuel consumption.

Would you have any suggestions? Compression on all cylinders are OK (78/80 psi). I really suspect it is Fuel Injection adjusts (it may operate too rich choked as it is ) and something with the CS propeller.

Any help suggestions very welcome!
__________________
Alexandre "neck" Marton
Brazil
RV7A (8/2015 built by FLYER)
Lycoming 180 HP - YIO-360-M1B, Hartzell C2YR-1BFP/F7497 72, Garmin panel - G3X Touch, GTN650, GTS800, WX-500, BATT CONCORDE RG-25XC AEROBATIC SEALED.
-------------
Others: RV9A
Lycoming XIO320-D1A, Hartzell HC-C2YL-1BF/F7663-4 , CS GOVERNOR MTV-12-B, DYNON D180
AND GARMIN AVIONICS
(Sold with aprox 300hrs flown from Dec/2010 -- JUN/2014)
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  #2  
Old 06-05-2017, 12:46 PM
rv7charlie rv7charlie is offline
 
Join Date: May 2006
Location: Pocahontas MS
Posts: 1,901
Default need more info

Which io360; parallel valve or angle valve? (20 HP difference for stock lycs of either configuration)

Fuel flow does sound high for cruise power, and if you have major egt spreads, that obviously needs to be addressed. Don't forget to check ignition timing; if it's set late it will raise egt's and reduce power. To check power output, measure max climb rate near sea level at full throttle and 2700 rpm. Compare to Van's climb numbers for your engine/airframe. If you're close to Van's climb number, you're likely making full power.

Having said that, realize that 75% power at ~8000 feet altitude is: properly leaned, with the throttle wide open and the c/s prop adjusted for 2700 rpm; not 2500. Find a copy of a Lyc owner's manual & study the power charts.

Properly leaned, assuming a 'stock' engine, a 180 HP engine should burn ~10.125 gph at 75% power, and a 200 HP engine should burn ~11.25 gph. Both numbers assume BSFC of .45 lbs per HP per hour. A bit better numbers if you have properly tuned and functioning electronic ignition, but not a really big difference.

Make sure you have all fairings in place and aligned properly.
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  #3  
Old 06-06-2017, 01:49 PM
ALMARTON ALMARTON is offline
 
Join Date: Mar 2010
Location: BRAZIL
Posts: 110
Default

Quote:
Originally Posted by rv7charlie View Post
Which io360; parallel valve or angle valve? (20 HP difference for stock lycs of either configuration)
Parallel valve IO 360 180hp

Quote:
Originally Posted by rv7charlie View Post
Don't forget to check ignition timing; if it's set late it will raise egt's and reduce power.
How to check ignition timing? Mag drop is ok though... 80 rpm drop on each mag...

Quote:
Originally Posted by rv7charlie View Post
To check power output, measure max climb rate near sea level at full throttle and 2700 rpm. Compare to Van's climb numbers for your engine/airframe. If you're close to Van's climb number, you're likely making full power.
Ok, I will check max climb sea level... will take a while though (cause I live in the mountains, gonna have to take time to travel )



Quote:
Originally Posted by rv7charlie View Post
Having said that, realize that 75% power at ~8000 feet altitude is: properly leaned, with the throttle wide open and the c/s prop adjusted for 2700 rpm; not 2500. Find a copy of a Lyc owner's manual & study the power charts.
Yeah you are right , I got 75% power at 7500 ft 72 F with 21,6 MAP doing 13,6 gals... but speed is only 155 TAS

BUT I GOT SOME NEWS....

The aircraft is on the maintenance shop as now, they found out the fuel pump was damaged... rubber diaphragm was torn, there was gasoline in the oil sump , etc...

Very bad... although I did not notice anomaly on the operation temperatures or pressures... the oil was diluted by gasoline , and there was some internal and possibly (in flight) leakage of gasoline. That explains why my fuel flow when set to cruise (all settings done) were strangely fluctuating a lot ... it looks there were no permanent damages... and after replacing the fuel pump, cleaning the fuel system, filters , nozzles and regulating the fuel injector and divider I will have a totally different plane...can't wait to see.

At least will solve the fuel consumption will problems I hope, but I am wondering if I will get some extra HP's from this adjusts...

Many thanks for any previous and future inputs!
__________________
Alexandre "neck" Marton
Brazil
RV7A (8/2015 built by FLYER)
Lycoming 180 HP - YIO-360-M1B, Hartzell C2YR-1BFP/F7497 72, Garmin panel - G3X Touch, GTN650, GTS800, WX-500, BATT CONCORDE RG-25XC AEROBATIC SEALED.
-------------
Others: RV9A
Lycoming XIO320-D1A, Hartzell HC-C2YL-1BF/F7663-4 , CS GOVERNOR MTV-12-B, DYNON D180
AND GARMIN AVIONICS
(Sold with aprox 300hrs flown from Dec/2010 -- JUN/2014)
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  #4  
Old 06-06-2017, 02:12 PM
airguy's Avatar
airguy airguy is offline
 
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 3,683
Default

Are you running standard 100LL fuel or some type of pump gas or ethanol blend?
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Greg Niehues - VAF 2017 dues paid
Garden City, TX
N16GN flying! http://websites.expercraft.com/airguy/
Built an off-plan 9A with too much fuel and too much HP. Should drop dead any minute now.
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  #5  
Old 06-06-2017, 03:24 PM
rvbuilder2002 rvbuilder2002 is offline
 
Join Date: Jul 2005
Location: Hubbard Oregon
Posts: 6,507
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Quote:
Originally Posted by airguy View Post
Are you running standard 100LL fuel or some type of pump gas or ethanol blend?
An important question that needs to be answered.

I know that in large portions of Brazil their auto fuel is spec'ed at 25% ethanol, but in reality it is more like 30-32%. This would have a major impact on HP and performance (and fuel economy).
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Scott McDaniels
Hubbard, Oregon
RV-6A (aka "Junkyard Special ")
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  #6  
Old 06-06-2017, 03:24 PM
ALMARTON ALMARTON is offline
 
Join Date: Mar 2010
Location: BRAZIL
Posts: 110
Default

Quote:
Originally Posted by airguy View Post
Are you running standard 100LL fuel or some type of pump gas or ethanol blend?
Only AVGAS 100/130 LL ! But I do suspect from the dealers somehow adulterating it for profit...

Anyway the thing I cannot understand yet is HOW a failure on the mechanical fuel pump could pour gasoline into the engine oil sump...I thought the lines were very separated... Does anyone can explain me that?
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Alexandre "neck" Marton
Brazil
RV7A (8/2015 built by FLYER)
Lycoming 180 HP - YIO-360-M1B, Hartzell C2YR-1BFP/F7497 72, Garmin panel - G3X Touch, GTN650, GTS800, WX-500, BATT CONCORDE RG-25XC AEROBATIC SEALED.
-------------
Others: RV9A
Lycoming XIO320-D1A, Hartzell HC-C2YL-1BF/F7663-4 , CS GOVERNOR MTV-12-B, DYNON D180
AND GARMIN AVIONICS
(Sold with aprox 300hrs flown from Dec/2010 -- JUN/2014)
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  #7  
Old 06-06-2017, 03:50 PM
airguy's Avatar
airguy airguy is offline
 
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 3,683
Default

The mechanical fuel pump is driven by a cam and pushrod inside the engine crankcase. The internal mechanism on the fuel pump separates the fuel side from the crankcase side with a rubber diaphragm, which is what your mechanic found was torn. If that diaphragm tears then the fuel can pass through the diaphragm into the crankcase area and into the oil sump, diluting the oil. It is a common symptom of a torn diaphragm on a fuel pump.
__________________
Greg Niehues - VAF 2017 dues paid
Garden City, TX
N16GN flying! http://websites.expercraft.com/airguy/
Built an off-plan 9A with too much fuel and too much HP. Should drop dead any minute now.
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  #8  
Old 06-06-2017, 04:09 PM
ALMARTON ALMARTON is offline
 
Join Date: Mar 2010
Location: BRAZIL
Posts: 110
Default

Quote:
Originally Posted by airguy View Post
The mechanical fuel pump is driven by a cam and pushrod inside the engine crankcase. The internal mechanism on the fuel pump separates the fuel side from the crankcase side with a rubber diaphragm, which is what your mechanic found was torn. If that diaphragm tears then the fuel can pass through the diaphragm into the crankcase area and into the oil sump, diluting the oil. It is a common symptom of a torn diaphragm on a fuel pump.

Nice explanation "Airguy" ! Many thanks almost a lecture!


I'm spending a lot here , those fuel pump reach us after tax for $ 830 US$

But if I got my fuel burn rate (consumption) right and maybe gain some performance I'll be glad and with peace of mind. And I'm learning at cost but am...
__________________
Alexandre "neck" Marton
Brazil
RV7A (8/2015 built by FLYER)
Lycoming 180 HP - YIO-360-M1B, Hartzell C2YR-1BFP/F7497 72, Garmin panel - G3X Touch, GTN650, GTS800, WX-500, BATT CONCORDE RG-25XC AEROBATIC SEALED.
-------------
Others: RV9A
Lycoming XIO320-D1A, Hartzell HC-C2YL-1BF/F7663-4 , CS GOVERNOR MTV-12-B, DYNON D180
AND GARMIN AVIONICS
(Sold with aprox 300hrs flown from Dec/2010 -- JUN/2014)
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  #9  
Old 06-06-2017, 04:22 PM
rv7charlie rv7charlie is offline
 
Join Date: May 2006
Location: Pocahontas MS
Posts: 1,901
Default

Sounds like you've solved the excess fuel issue; now the speed issue:

Quote:
Originally Posted by ALMARTON View Post
Parallel valve IO 360 180hp
How to check ignition timing? Mag drop is ok though... 80 rpm drop on each mag...

Yeah you are right , I got 75% power at 7500 ft 72 F with 21,6 MAP doing 13,6 gals... but speed is only 155 TAS

Many thanks for any previous and future inputs!
If you haven't set the mag (ignition) timing before, get someone with experience to bring their mag timing 'buzz box' & work with you, or let your mechanic do it. It's not hard, if you know how to do it. If you don't, you could do some real damage.

In your 1st post, you said "Guess that because currently it is doing only 151kts TAS (2400rpm) at 65% power at @ 8000 ft OR... 155 kts at 75% (2500 rpm -same altitude conditions). And it does that consuming a lot of gas... about 12 gals at 65% or 13,5 gals at 75% power! - best power ROP adjust -"

Did you re-fly the test at wide open throttle, leaned for best power (not an EGT number, but actual best power, as observed on the airspeed indicator), and *2700* rpm? Until you do, you're not making 75% power at that altitude (unless you're running a turbo).

Hope that helps,

Charlie
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  #10  
Old 06-06-2017, 05:11 PM
rzbill's Avatar
rzbill rzbill is offline
 
Join Date: Nov 2005
Location: Asheville, NC
Posts: 2,370
Default

Alexandre,
For clarity to the group, please specify how you are determining % power.
Is it from a Lycoming chart or graph showing MP and RPM or from an EFIS display that was programmed by the original builder?
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Bill Pendergrass
RV-7A: Flying since April 15, 2012. 550hrs
YIO-360-M1B, mags, CS, GRT H1s & A/P, Navworx
Unpainted, polished....kinda'
My RV Construction Page
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