Matronics Email Lists Forum Index Matronics Email Lists
BBS 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 

Another RV-10 flying! (with some performance questions)

 
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> RV10-List
View previous topic :: View next topic  
Author Message
TimRVator(at)comcast.net
Guest





PostPosted: Sun Jan 29, 2017 7:10 pm    Post subject: Another RV-10 flying! (with some performance questions) Reply with quote

Excellent fuel pump reference (how the pump works, expected pressure
output, what happens to engine fuel flow if pressure is too low, etc):
https://www.youtube.com/watch?v=_BfwuUjh_lA

Data point: My AFS logs show 22-24 psi at 8500 on a flight a couple of
years ago. I've recently had fuel pressure drop to 18psi occasionally
(at lower altitude), and am in the process of replacing the engine
driven pump to address that. No results to report yet.

--
Tim Lewis -- HEF (Manassas, VA)
A&P
RV-6A N47TD -- 1104 hrs - sold
RV-10 N31TD -- 850 hrs

Dan Charrois wrote on 1/29/2017 4:34 AM:
Quote:


Hi everyone.

I'm happy to say that after 11+ years of work, my RV-10 is finally in the air. As a testament to Van's incredible design (both in terms of the airframe performance and reliability, and perhaps equally importantly, in producing a kit that newcomers to the idea of homebuilding can build safely) , the first flight (and subsequent ones) have been pretty much uneventful. Everything "just works" - the plane handles like a dream and I'm looking forward to spending thousands of hours flying it. Still a ways to go yet - I'm currently at 9 hours of flight time in it Smile

But as nice as the plane seems to be, I'm in the phase right now of analyzing the heck out of everything to make sure it's operating as it should (fortunately, I have some AFS EFISes in there that log data for me to go over afterwards). And though the plane is operating 99% as well as I hoped for, there are a couple of things not operating quite as I expected - I'm after other people's advice to see if they've experienced something similar. Any help or insight anyone can give on any of these issues would be greatly appreciated!

My plane is a pretty standard build with a factory-new Lycoming IO-540 D4A5 and 3-bladed MT prop.

1. Fuel pressure drop climbing to higher altitudes: Today, I did an "informal" climb at 110 KIAS and 2500 RPM/full throttle/full rich to 10000' to see how it would handle it. At around 3200' MSL, I see a fuel pressure of about 21psi with the engine pump (boost pump off). But in the climb, the fuel pressure drops significantly. At 5000', it's at 18psi, at 7000' it was about 16psi, then it started dropping faster. At 8000' it was down to 13psi and by 8700' had dropped down to 11psi. I turned the boost pump back on and it promptly shot back up to 20psi, so I continued the climb to 10000' and then made my way back down. By the time I got back down to 4300' I turned the boost pump off and the engine pump maintained pressure at 22psi. I never did take the chance to level out and test pressure further - without knowing if it was a significant cause for concern, I got back down to the lower altitudes instead. I haven't seen any significant pressure fluctuations in flying a!
round under 5000'.

According to the Lycoming manual, the fuel pressure for the IO-540-D4A5 at the fuel injector is supposed to be between 14 and 45 psi. This is where the Van's stock fuel pressure sensor is measuring, isn't it? Though I've seen at least two other pilot's RV-10 POHs that use numbers for the acceptable pressure to be what Lycoming quotes as that for the inlet to the fuel pump of -2 to 35 psi, so it's got me wondering if I'm misinterpreting either the Lycoming documentation or the fuel plumbing. So the question I have - is that low fuel pressure the cause for concern I think it is? If so, what might be causing it, and how would I fix it? Or is it normal? What do other people see in climb to 10000'? Though I can use the boost pump for climbs to higher altitudes (and I've heard of some certified aircraft that suggest it), it doesn't strike me as an appropriate measure if the boost pump were to fail.

2. Rate of climb at high altitudes: I haven't constructed the wheel pants yet, so I know performance will improve when they're done. At low altitudes I certainly can't complain about rate of climb - with 450 pounds of fuel and me, I did a short field takeoff today climbing out at about 85 knots and saw a 2150 fpm climb rate. But when I got up near the 10000' point, at 110 KIAS, I was only getting around 500 fpm. I haven't done proper climb charts yet, but since I've heard of lots of people cruising in the RV-10 at 15000'-17000', how are they getting up there? My climb was at full rich, as I've been taught to do in lower performing planes - is it standard practice to lean out the mixture in climbs up at that altitude for more power? Or perhaps a slower climb speed/steeper angle than my 110 KIAS?

3. Performance in general: I did some airspeed indicator calibrations today at different power settings at 3200', and ended up with the following true airspeeds: 25"/2500RPM: 150 knots, 24"/2400 RPM: 147 knots, 23"/2300 RPM: 141 knots, 21"/2300 RPM: 134 knots, 18"/2300 RPM: 118 knots, 16"/2200 RPM: 103 knots. These numbers are without wheel pants, but with that in mind, do they seem reasonable? Vans' web site suggests cruise at 171 knots at 75% power at 8000'. I know that claims should be taken with a grain of salt, and I didn't run these tests at 8000', but if my calculations are correct, at 25"/2500 RPM I should have been producing about 80% power. Is it expected that the wheel pants and/or a higher altitude are going to make a significant enough improvement to get closer to Van's numbers?

4. CHT temps: To break in the engine, I've been running it pretty hard - usually around 25"/2500 most of the time (with some cycling to 25"/2600 or down to 24"/2400 to avoid building a ridge in the cylinder). In cruise with those power settings, my cylinders 3 and 4 run comparatively cool at around 375F. Cylinders 2, 5, and 6 are about 410F, but cylinder 1 is a bit of an anomaly. Usually it's the hottest of all, getting up to around 440 (5 degrees hotter than Lycoming's recommendation for maximum service life), though there have been a few times where it's dropped rather abruptly by 50-60 degrees (for no apparent reason I can see), making it surprisingly suddenly the coolest cylinder. But it doesn't stay there - after awhile, it climbs back up to step in line with what cylinders 2, 5, and 6 are doing... but usually stays 20-30 degrees hotter than the rest. Outside temperatures have been around 30-40 Fahrenheit during the flights so far.

Of course, at lower power settings, the CHTs all drop down to well under 400. And all power settings, the engine operation has been very smooth - no roughness at all.

I can reduce the height of the dam in front of cylinder 1, and I've heard of lots of people having to do that. But especially with the strange temperature fluctuations I'm still not sure if it's fully broken in yet, so I've been holding off until things settle. Has anyone else noticed a hot cylinder 1, and if so, how much of the front dam did you remove to cool it down? The good thing is my centre two cylinders seem plenty cool so I should be able to sacrifice some of their airflow to get #1 down.

5. Break in: I've flown the engine pretty hard now for 9 hours, but haven't seen any dramatic sign of CHTs reducing as is supposed to happen with a break in (with that said, the engine was run in at Lycoming for about an hour, and about 45 minutes on the ground under supervision of an aircraft engine shop for further break in before first flight). Other indications like "until the oil consumption has stabilized" haven't helped either - I put in about 3/4 quart of oil at about the 6 hour mark, but that's been it.... so far, it hasn't used excessive oil, and as I've only added oil once, I'm unsure of how to even define "stabilized". Now that I'm at the 9 hour mark for flight (11 hours on the engine overall), should I conclude that the engine is probably broken in about as good as it's going to get, or should I still be holding out for a noticeable drop in CHTs?

Sorry for the long email! But if anyone has any suggestions, advice, or comments on any of these or other issues, I'd certainly appreciate hearing from you!

I'm looking forward to meeting with some of you at fly ins, as soon as I finish flying off the 25 hours I need to do first!

Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213


- The Matronics RV10-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?RV10-List
Back to top
dan(at)syz.com
Guest





PostPosted: Tue Jan 31, 2017 2:33 am    Post subject: Another RV-10 flying! (with some performance questions) Reply with quote

Thanks for all the responses, everyone! And as it turns out, the timing is good for doing some adjustments and tweaks. Since the weather here is supposed to be not great for a little while, and since it was getting to be about time for the first oil filter inspection/oil change anyway, I think I'll be pulling a few more things apart for inspection while I'm at it. With 9 hours of initial flight time, I figure it might not be a bad time to give it the equivalent of an annual to make sure everything is working as it should.

With regards to my engine pump, it's somewhat encouraging that some people have also noticed a pressure drop while climbing. But not everyone seems to - a lot of people have reported very little if any loss of pressure. Along the way I've learned a lot about how engine fuel pumps work (thanks for the YouTube link, Tim!). Over the next few days, I'm going to be pulling apart my fuel filters and strainers to see if any contamination or blockages have made their way in (quite possible after construction - and now I certainly hope so, since that would be an easy fix!), and will certainly check for possible kinks or air leaks into the fuel lines too. I have an Andair fuel selector valve with an extension so the valve is towards the bottom of my tunnel, eliminating at least one potential issue.

Here in Canada, we need to have gascolators installed at the lowest point in the fuel system to pass inspection (bureaucracy, not science), so there's another point of potential failure in my fuel system that isn't in Van's plans. I have my gascolators in the wing roots, so there's another filter the pumps have to pull fuel through that potentially drops the pressure. You can bet those are going to go through some intense scrutiny too.

What I just don't understand though is why at low altitude and high power settings (25"/2500, and around 20 gph), I'm seeing an OK fuel pressure of around 22 psi.. but for some reason when I did my climb, the pressure went way down even though the flow stayed the same.. and then when I got back to a lower altitude, the pressure went right back up again. I'm not sure if it was related to altitude, high power for an extended period, or climb attitude. Once I finish going through the system for leakage, blockages, etc. and get the plane back in the air, if I'm still having trouble, my plan is to try a step climb to try and isolate whether altitude or attitude is more likely causing the issue in the first place.

With the rental planes I've flown in the past, the mantra was always just to go full rich for climb, but very few of those planes could easily get to 10000' anyway. Leaning for climb seems to definitely be the recommended practice for the RV-10, and thanks for the advice of keeping the hottest EGTs at a consistent temperature throughout the climb. In my full rich climb, they cooled by about 160 degrees throughout the climb, so there is certainly a fair bit of leaning I could have been doing to keep things efficient. Leaning will also reduce fuel flow, which should increase fuel pressure... though if I'm still having trouble maintaining pressure at richer mixtures I'm still going to be a bit concerned.

Regardless, I definitely have to get my CHTs down, especially if the plan is to climb with a leaner mixture. My baffling and sealing under the cowl is currently pretty minimal - nothing more than as per Van's instructions. The plan now is to use more RTV in all the nooks and crannies where air is undoubtedly leaking out pointlessly, as well as cap off the holes in the aft baffle where the engine mount protrudes. From what people say, that should improve cooling significantly. I'll also take off a good portion of the dam in front of cylinder 1 to try to bring it more inline with the rest.

And getting those wheel and gear leg fairings done certainly won't hurt with cooling or performance either. I'm going to move them off the back burner and get them done as soon as I can.

Despite my high CHTs, somehow my oil temperature behaves much nicer - so far, it's only gotten to about 180 and stays around there, regardless of power settings, altitude, etc.

I've been keeping the oil at about 8 quarts, and added a bit when it looked like it got down to around 7.5. The dipstick just has marks at 6 and 9 so both were guesttimates - I'll measure more precisely the oil level before each flight and when I add so I can get a more accurate idea of oil consumption... I'm not even altogether sure if I've just lost oil via the breather tube at 8 quarts. If it gets down to around 7.5 again, I might leave it there for awhile to see if it continues to drop further.

Thanks again, everyone, for all of the very helpful advice and insight! Despite the thrill of finally taking the plane up, it's time to buckle down and spend another couple of weeks working on it to try and improve what I've seen so far!

Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213


- The Matronics RV10-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?RV10-List
Back to top
flying-nut(at)cfl.rr.com
Guest





PostPosted: Tue Jan 31, 2017 5:59 am    Post subject: Another RV-10 flying! (with some performance questions) Reply with quote

I agree with Kelly ..... if the flow doesn't change then neither does the pressure ..... at the spider.  Again, your flow gauge is, in reality, a pressure gauge calibrated for known orifices in the injectors to read flow in gallons per hour.  They just measure at different points.  I'd look more closely at the fuel pressure sensor and fly ..... above the airport, of course just in case.  Now that you know what to look for ..... fuel pressure and fuel flow ..... it might be an opportunity to narrow down the culprit rather than indict 'something in the fuel system'.  Since it's early in the flight testing, I wonder if the high(er) angle of attack might break loose a little bubble of air trapped somewhere in the system.  Engine driven pumps do not handle vapor well at all.  Testing might cover climbing to see if you can duplicate the pressure loss, and if so climb with the boost pump on .... they operate differently ..... to see if there's a change.
There are so many variables present that you might be chasing a 'problem' that doesn't exist.  Having said that, your 'early annual' is good for safety (if there is a problem) and mental calm.  I live by the 'if it isn't broke, don't fix it' mantra ..... which puts the onus on determining if it's broke first.
Linn .... hoping to cover this ground this fall


On 1/31/2017 8:17 AM, Kelly McMullen wrote:

Quote:
I don't recall if it was suggested, but you might want to either Tee in a calibrated fuel pressure gauge, or just substitute one to see if your engine monitoring system is reporting fuel pressure accurately. The mechanical pump is used on a variety of engines, a lot of the fuel injected models using the same part number. Both the 4 cyl 200 hp engine on my Mooney and the IO-540 of my -10 use the same pump. They both produce indicated 25-27 psi and the boost pumps increase that by 1-2 psi. While I don't think gascolators on the suction side should create much restriction, who knows. One other thought...the fuel vent line is supposed to have 45 degree cut to slightly pressurize the tank. (section 44-7), . If the tank isn't at atmospheric pressure or better at higher altitude the pump has to work harder.

Easy way to check for air leaks between boost pump and mechanical is to simply turn on boost pump with mixture at cutoff until it reaches max pressure, turn it off, and see how long the system holds that pressure.
-sent from the I-droid implanted in my forearm







On Tue, Jan 31, 2017 at 3:32 AM, Dan Charrois <dan(at)syz.com (dan(at)syz.com)> wrote:
Quote:
--> RV10-List message posted by: Dan Charrois <dan(at)syz.com (dan(at)syz.com)>

Thanks for all the responses, everyone!  And as it turns out, the timing is good for doing some adjustments and tweaks.  Since the weather here is supposed to be not great for a little while, and since it was getting to be about time for the first oil filter inspection/oil change anyway, I think I'll be pulling a few more things apart for inspection while I'm at it.  With 9 hours of initial flight time, I figure it might not be a bad time to give it the equivalent of an annual to make sure everything is working as it should.

With regards to my engine pump, it's somewhat encouraging that some people have also noticed a pressure drop while climbing.  But not everyone seems to - a lot of people have reported very little if any loss of pressure.  Along the way I've learned a lot about how engine fuel pumps work (thanks for the YouTube link, Tim!).  Over the next few days, I'm going to be pulling apart my fuel filters and strainers to see if any contamination or blockages have made their way in (quite possible after construction - and now I certainly hope so, since that would be an easy fix!), and will certainly check for possible kinks or air leaks into the fuel lines too.  I have an Andair fuel selector valve with an extension so the valve is towards the bottom of my tunnel, eliminating at least one potential issue.
  
   








- The Matronics RV10-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?RV10-List
Back to top
Kellym



Joined: 10 Jan 2006
Posts: 1369
Location: Sun Lakes AZ

PostPosted: Tue Jan 31, 2017 6:14 am    Post subject: Another RV-10 flying! (with some performance questions) Reply with quote

The pressure at the flow divider is controlled by the fuel servo. The
pressure pick-off is at the servo, in the inlet area, and reflects the
fuel pump pressure. The servo will control output pressure to the flow
divider, which also determines the fuel flow. However, the fuel servo
needs a minimum input pressure of around 14-15 psi to have full control.
The fuel flow sensor that most systems use is a positive displacement
spinning wheel, and is insensitive to pressure. (red cube and similar
devices)

On 1/31/2017 6:58 AM, Linn Walters wrote:
Quote:
I agree with Kelly ..... if the flow doesn't change then neither does
the pressure ..... at the spider. Again, your flow gauge is, in
reality, a pressure gauge calibrated for known orifices in the injectors
to read flow in gallons per hour. They just measure at different
points. I'd look more closely at the fuel pressure sensor and fly .....
above the airport, of course just in case. Now that you know what to
look for ..... fuel pressure and fuel flow ..... it might be an
opportunity to narrow down the culprit rather than indict 'something in
the fuel system'. Since it's early in the flight testing, I wonder if
the high(er) angle of attack might break loose a little bubble of air
trapped somewhere in the system. Engine driven pumps do not handle
vapor well at all. Testing might cover climbing to see if you can
duplicate the pressure loss, and if so climb with the boost pump on ....
they operate differently ..... to see if there's a change.
There are so many variables present that you might be chasing a
'problem' that doesn't exist. Having said that, your 'early annual' is
good for safety (if there is a problem) and mental calm. I live by the
'if it isn't broke, don't fix it' mantra ..... which puts the onus on
determining if it's broke first.
Linn .... hoping to cover this ground this fall


- The Matronics RV10-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?RV10-List

_________________
Kelly McMullen
A&P/IA, EAA Tech Counselor # 5286
KCHD
Back to top
View user's profile Send private message
Tim Olson



Joined: 25 Jan 2007
Posts: 2608

PostPosted: Tue Jan 31, 2017 8:15 am    Post subject: Another RV-10 flying! (with some performance questions) Reply with quote

At higher altitudes the fuel will vaporize easier. Additionally, most
of the time while you're climbing the airflow thru the cowl isn't
as good. So, you have heat buildup causing vapor, and altitude making
vapor easier to form. With the fuel pump behind the
engine, it's in an area of higher heat. So, vapor can be a
problem. There are PLENTY of people who have noticed this
in their RV-10s. There are some who have not.
I certainly wouldn't replace a fuel pump over it, because it
is common enough that I don't believe it to be highly abnormal.
This has happened to me maybe 25 times or 30 times in
1200 hours...maybe more, but not every flight. Usually
it happens when I get over 8000'. Never has the pressure
actually dropped enough that the engine felt it.
I have seen as low as 12PSI. Leaning for climb helps,
because you reduce the flow which increases the pressure.
Climbing slower helps because you cool better.

I HAVE seen it happen where running the boost pump for 30 seconds
takes care of it and it doesn't re-occur. Other times it may
come back in a minute or two. Maybe it's a pocket of vapor
that gets blow thru with the boost pump. Either way, the
important thing is you know it's happening and most EFIS
systems will audibly alert you. When I get the alert I
just look at the gauge, turn on the pump, and the problem
is over.

I did buy a fuel pump cooling shroud from Aircraft Spruce at one
with the intent of adding blast cooling to my fuel pump.
I never bothered to install it because it's kind of a
pain to get into that area and install it, or even
replace the fuel pump in the first place. I decided that
it wasn't worth the effort for an occasional occurrence.

It's not bad that you're going to go thru all the inspection work,
but I wouldn't sweat it too much about the fuel pressure in
climb unless it happens to you all the time. Try climbing
at 120kts and try a few things before you spend too
much worry over it.

Tim

On 1/31/2017 4:32 AM, Dan Charrois wrote:
Quote:
What I just don't understand though is why at low altitude and high
power settings (25"/2500, and around 20 gph), I'm seeing an OK fuel
pressure of around 22 psi.. but for some reason when I did my climb,
the pressure went way down even though the flow stayed the same.. and
then when I got back to a lower altitude, the pressure went right
back up again. I'm not sure if it was related to altitude, high
power for an extended period, or climb attitude. Once I finish going
through the system for leakage, blockages, etc. and get the plane
back in the air, if I'm still having trouble, my plan is to try a
step climb to try and isolate whether altitude or attitude is more
likely causing the issue in the first place.


- The Matronics RV10-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?RV10-List
Back to top
View user's profile Send private message Send e-mail
dan(at)syz.com
Guest





PostPosted: Tue Jan 31, 2017 10:25 pm    Post subject: Another RV-10 flying! (with some performance questions) Reply with quote

Hi John. Thanks for sending your data along for comparison.

Quote:
I have just been looking at my numbers from the AFS 4500 System on my Rv10
with the IO-540 D4A5,
Your performance numbers are pretty much the same as mine so when you get
your wheel Pants and Spats sorted out I think you
Will have no trouble getting better than 170 KTAS. The best I have seen on
mine so far has been 173 at 9000 ft WOT.

That's encouraging! Good to hear that I'm not way out in left field.

Quote:

As for CHTs they seem a bit high from what I am seeing here. I have to
convert my numbers for you because here in VH we
use a Hybrid system where volume and Temp are metric.

In Canada we use a hybrid system too, but not so straightforward as you. We tend to use metric for most things too, except when it comes to people and buildings. Everyone knows their weight and height in pounds and feet - nobody has the slightest idea how many kg or metres they are. For buildings we tend to use how many feet high they are, how many feet high in area, etc. In rural areas, places are considered to be so many miles apart, but highway sign posts and "city people" think in kilometres. Outside temperatures are in degrees C, except for things like oven temperatures, which are in Fahrenheit. For flying, perhaps because we're right beside the US, nothing is done in metric... except outside temperature Smile
Quote:
You don't show Fuel
flow numbers for your figures but at Sea Level
We look for 96 litres /hour which if I convert for you is 25.4 gph.

I got about 22 gph on takeoff and initial climb to 1000' AGL, so that seems at least comparable to your numbers (our airport is 2200 feet MSL). On the climb I did to 10000', at full rich mixture, my fuel flow was between 20-22 gph (though my fuel flow transducer hasn't been calibrated yet against real world usage, so those readings may be off a bit). Just the pressure that went down.

Quote:

Climbing to 7500 ft and WOT the highest my CHTs got was around 198 deg C
which is 388 deg F.
This was when the engine had about 25 hours on it. The Delta from OAT of 25
deg (77 F ) was 173 deg C or (311 deg F).
Now that the engine has about 85 hours on it, it is running a little cooler
with the Hottest being 194 C (381 deg F) for a delta of
167 deg C (301 deg F).

So putting a few more hours on it have made the temps come down a bit, by a
around 10 deg F.

I'm going to be plugging up some of the gaps in baffles under the cowl to improve cooling over the next little while to try and get the CHTs down as much as I can. And of course, removing a large part of the dam in front of cylinder 1.

Quote:

As for your #1 Cylinder doing funny stuff, I had my number 2 doing a similar
thing. It would go high at full power
and then flip suddenly to under all the others when I leaned the engine. It
turned out it was a partially blocked
Injector. I couldn't work out what it was in there except that I could see a
very slight whisker of something in the
Orifice when I looked through it. We couldn't get it out with air or an
Ultrasonic Cleaner, so I resorted to a
Very fine piece (much finer than the drill size of the orifice) of copper
wire to poke it out. Problem fixed!

Interesting you should say this.

In looking at my data, I originally thought that the drops in temps for cylinder 1 seemed to happen randomly, but on closer investigation, it looks like it might have happened a few times where I leaned more aggressively. And I'd also recently read in one of the many CHT/EGT information sheets online that this could be due to a partially blocked injector as you experienced.

I'd definitely like to pull the injector and take a look, as in hearing from what happened to you, I'm thinking it even more likely that this may be a possibility for me. It's certainly something I need to check, if for no other reason than to rule it out. But I haven't touched the injectors yet - they were pre-installed on the factory Lycoming. Before I pull the injector for cylinder 1 to look at it, is there a gasket involved that I should have a replacement for? Or can the gasket (if any) on the injector be re-used?

Quote:
So after all of that check your Fuel flow is above 25 Gph at sea level on
takeoff just to be sure that the Servo
Is giving the Engine enough fuel.

According to my fuel flow transducer, it's slightly less (about 22 gph) at 2200'. But that's just off the factory "default" calibration of the transducer, so it may be a bit off. And I'm not sure if the 2200' elevation would have that much an effect on fuel flow either.

When I did a flow test with the fuel line disconnected to the servo, using the boost pump before my first flight, it was able to pump about 50 gph, so at least then, there didn't seem to be any major flow restrictions (or if there were, the boost pump was able to overcome them). But things may have settled or particles gotten trapped in my filters over the past few flights I've done. At any rate, over the next day or two I'm going to be pulling apart the filters to look for contamination, and checking the fuel lines carefully to see if any air might be leaking into the lines.

Thanks for your numbers and sharing your experiences!

Dan
---
Dan Charrois
President, Syzygy Research & Technology
Phone: 780-961-2213


- The Matronics RV10-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?RV10-List
Back to top
Display posts from previous:   
Post new topic   Reply to topic    Matronics Email Lists Forum Index -> RV10-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 can download files in this forum


Powered by phpBB © 2001, 2005 phpBB Group