Today's Message Index:
----------------------
1. 05:22 AM - Re: Airbox mod (rv10flyer)
2. 05:28 AM - FAB wars (Chris Hukill)
3. 05:55 AM - Re: FAB wars (Linn Walters)
4. 06:29 AM - Re: Re: Airbox mod (Kelly McMullen)
5. 06:57 AM - Re: FAB wars (Tim Olson)
6. 07:25 AM - Re: Re: Airbox mod (Carl Froehlich)
7. 07:59 AM - Re: Airbox mod (rv10flyer)
8. 08:55 AM - Re: Re: Airbox mod (Linn Walters)
9. 10:31 AM - Re: Re: Airbox mod (Kelly McMullen)
10. 11:33 AM - Re: FAB wars (Bob Turner)
11. 03:35 PM - Re: Re: FAB wars (Kelly McMullen)
12. 04:30 PM - Re: FAB wars (Bob Turner)
13. 06:16 PM - Pitot location (bob88)
14. 07:06 PM - Re: Pitot location (Ben Westfall)
15. 07:11 PM - Re: Re: FAB wars (Kelly McMullen)
16. 07:44 PM - Trim servo question (bob88)
17. 07:46 PM - Re: Pitot location (Linn Walters)
18. 10:00 PM - Re: Pitot location (Pascal)
19. 10:24 PM - Re: Airbox mod (rv10flyer)
20. 10:35 PM - Re: Re: Airbox mod (Kelly McMullen)
21. 11:07 PM - Re: Pitot location (Justin Jones)
22. 11:15 PM - Re: Airbox mod (rv10flyer)
23. 11:41 PM - Re: Airbox mod (Bob Turner)
Message 1
| INDEX | Back to Main INDEX |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Our factory provided air filter has barely enough surface area for a 540. I would
not want to remove 30% of its area for normal operations. Good luck with your
mod.
--------
Wayne G.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429341#429341
Message 2
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Glad I could help with the FAB wars. I appreciate the comments and would
to respond to few. The three holes in the back are mathematically the
same area as the intake throat of the injection servo, so if the reeds
are fully open, the airflow would be the same as a hole in the bottom of
the airbox with Vans system. I doubt that Vans did any engineering on
the size of the filter area, as it=99s the same filter they use
for all the engine sizes. Off the shelf stuff. The proof is in the
pudding. On my RV8, with a souped up AEIO 360, and the same filter, the
loss is 10%, determined by actual tests. I attributed that loss to the
loss of ram effect, not filter area. The same actual test will be done
in my first 25 hours, and I will post results. I thought about
indicating on the EFIS, the reed valves movement with a simple micro
switch or even a potentiometer, and have provisioned for that with an
extra EMS circuit run to the engine. Or a video camera can be
temporarily installed. It will be there for initial testing, but
probably taken off after as I feel the airbox doesn=99t need to be
monitored, other than the slight, but noticeable loss of power . Simply
looking into the scoop during preflight will alert to any solid
contamination your may have ingested on your previous flight. I fail to
see how heavy rain will get to the protected side of the filter. The
rain that gets thru the ram portion of the filter will go into the
engine. How will a much higher pressure area, essentially vented to the
warm air that =98s cooling the engine, attract rain, sleet or ice?
I would chuckle too at the ingested bird scenario, if it hadn=99t
happened to my brother in his C172, right at takeoff at Hayward CA.
About 50 feet in the air and WHOMP! Engine quit and he was able to land
in the remaining runway. The front the cowl was completely destroyed by
the seagull and the filter was blocked by the feathers and guts. I
myself have hit several birds during takeoff in jets over my career. If
it hasn=99t happened to you, don=99t rule out the
possibility that it can.
Now, any opinions on which primer is best for airboxes?
Chris Hukill
Message 3
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
On 8/26/2014 8:28 AM, Chris Hukill wrote:
snip
> Now, any opinions on which primer is best for airboxes?
I like CCI primers, though I don't know if they'll fit an airbox!!! :-)
Linn
> Chris Hukill
> *
>
>
> *
>
> No virus found in this message.
> Checked by AVG - www.avg.com <http://www.avg.com>
>
Message 4
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
I'm curious how you reach that conclusion. There are exactly two
limiting orifices to the engine. One is the size of the cowling openning
to the FAB, and the other is the fuel injection servo itself. If the alt
air openning equals the size of the cowling opening you don't have any
restriction. If it equals the servo opening the only loss of power would
be from the differing flow directions and loss of ram air. The surface
area of the filter is several multiples of either of the limiting
openings. I doubt there is very much difference in flow through the
factory filter and the one I had on a 370 hp Camaro Z-28 I used to drive
and maintain(back when leaded 98 octane was available at most street
corners) which at 7000 rpm flowed a heck of a lot more air than a 540 at
270 rpm will. Meaningful flow restriction by an opening only occurs when
the pressure drop is sufficient to reach transonic speeds.
Also, look at the filter size on many certified planes in the same power
range and I think you will find a number that are smaller than the Vans
supplied filter. I know the filter for my 200 hp Mooney is a whole lot
less, and the filter bypass ram air opening is about the same size as
the flange to the fuel servo.
On 8/26/2014 5:21 AM, rv10flyer wrote:
>
> Our factory provided air filter has barely enough surface area for a 540. I would
not want to remove 30% of its area for normal operations. Good luck with
your mod.
>
> --------
> Wayne G.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429341#429341
>
>
Message 5
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Chris,
You're definitely correct that on takeoff a bird strike to the cowl
is much more likely, so the chances are much higher at that point.
Still, even if you ingested a bird with a standard FAB, and used
the standard door on the bottom, that would still suffice for the
solution. I'm not saying your FAB design is bad, and I don't have
any data on filter sizes for the airflow required and all of that,
and I understand you do. If your design gives plenty of airflow
with no restrictions, and you feel better with it, then I say
go for it, as long as it has no airflow downside. But, I think
that for 99% of the builders, doing anything besides reinforcing
the FAB bottom with Aluminum and having a single-use-then-manual
reset slide door on the bottom really has no big down side.
It'll open airflow for a birdstrike, iced up filter, and provide
plenty of airflow when needed....doing anything more than that
is just going to slow the builder down. I think that too many
people take WAY too long to complete their project, which just
leads to frustration for the builder. There are endless mods
that a person can do, and every 5, 10, 20 hours, especially for
the infernal fiberglass mods, often adds little value for
the effort put in. The fact is, when you are flying your
RV-10, most of these tweaks and mods bring no added joy to
the flying experience, and things such as the FAB mod, I feel
are really no real benefit to safety. Your method is cool,
but it doesn't do anything significant for safety that the standard
FAB offers. (this is NOT an insult or attack on you or your
FAB, as it does look real nice)
It took me 25 months to finish my RV-10 enough to get it in
the air, including the paint. I spent countless wasted hours
in a few mods, especially in the Andair fuel valve. That particular
mod I really do like, but I wasted a LOT of time doing it. Had
I not skipped a couple months of building, and had more builders
in front of me to learn from (I was approx. the 24th flying), I could
have saved probably 3 or 4 months of build time. By the time you
get done with a build, especially doing things like gear leg
fairings, all this work is just tedious and frustrating. So
I personally believe people would be better off taking Van's
advice...."Just build the plane."
Tim
On 8/26/2014 7:28 AM, Chris Hukill wrote:
> Glad I could help with the FAB wars. I appreciate the comments and would
> to respond to few. The three holes in the back are mathematically the
> same area as the intake throat of the injection servo, so if the reeds
> are fully open, the airflow would be the same as a hole in the bottom of
> the airbox with Vans system. I doubt that Vans did any engineering on
> the size of the filter area, as its the same filter they use for all
> the engine sizes. Off the shelf stuff. The proof is in the pudding. On
> my RV8, with a souped up AEIO 360, and the same filter, the loss is 10%,
> determined by actual tests. I attributed that loss to the loss of ram
> effect, not filter area. The same actual test will be done in my first
> 25 hours, and I will post results. I thought about indicating on the
> EFIS, the reed valves movement with a simple micro switch or even a
> potentiometer, and have provisioned for that with an extra EMS circuit
> run to the engine. Or a video camera can be temporarily installed. It
> will be there for initial testing, but probably taken off after as I
> feel the airbox doesnt need to be monitored, other than the slight, but
> noticeable loss of power . Simply looking into the scoop during
> preflight will alert to any solid contamination your may have ingested
> on your previous flight. I fail to see how heavy rain will get to the
> protected side of the filter. The rain that gets thru the ram portion of
> the filter will go into the engine. How will a much higher pressure
> area, essentially vented to the warm air that s cooling the engine,
> attract rain, sleet or ice? I would chuckle too at the ingested bird
> scenario, if it hadnt happened to my brother in his C172, right at
> takeoff at Hayward CA. About 50 feet in the air and WHOMP! Engine quit
> and he was able to land in the remaining runway. The front the cowl was
> completely destroyed by the seagull and the filter was blocked by the
> feathers and guts. I myself have hit several birds during takeoff in
> jets over my career. If it hasnt happened to you, dont rule out the
> possibility that it can.
> Now, any opinions on which primer is best for airboxes?
> Chris Hukill
>
> *
Message 6
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
If you invert the top cover of the stock Van's air box it will now fit the
taller K&N E-1000 filter.
As previously stated, recommend adding an aluminum plate between the bottom
of the filter and the fiberglass air box bottom. From experience I know the
filter will ablate the fiberglass over time. Talking to Van's on this they
are now recommending the same for people who call them about the problem.
Hopefully they will update the plans to reflect.
Carl
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Kelly McMullen
Sent: Tuesday, August 26, 2014 9:28 AM
Subject: Re: RV10-List: Re: Airbox mod
I'm curious how you reach that conclusion. There are exactly two limiting
orifices to the engine. One is the size of the cowling openning to the FAB,
and the other is the fuel injection servo itself. If the alt air openning
equals the size of the cowling opening you don't have any restriction. If it
equals the servo opening the only loss of power would be from the differing
flow directions and loss of ram air. The surface area of the filter is
several multiples of either of the limiting openings. I doubt there is very
much difference in flow through the factory filter and the one I had on a
370 hp Camaro Z-28 I used to drive and maintain(back when leaded 98 octane
was available at most street
corners) which at 7000 rpm flowed a heck of a lot more air than a 540 at
270 rpm will. Meaningful flow restriction by an opening only occurs when the
pressure drop is sufficient to reach transonic speeds.
Also, look at the filter size on many certified planes in the same power
range and I think you will find a number that are smaller than the Vans
supplied filter. I know the filter for my 200 hp Mooney is a whole lot less,
and the filter bypass ram air opening is about the same size as the flange
to the fuel servo.
On 8/26/2014 5:21 AM, rv10flyer wrote:
> --> <wayne.gillispie@gmail.com>
>
> Our factory provided air filter has barely enough surface area for a 540.
I would not want to remove 30% of its area for normal operations. Good luck
with your mod.
>
> --------
> Wayne G.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429341#429341
>
>
Message 7
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
>From K & N website...
A = (C.I.D. x RPM) / 20,839
A= 540 X 2,700 / 20,839
A= 70 sq in.
I already measured mine and it is undersized. One of the reasons many complain
of "shrinking filters". Pressure differential, fuel, oil, rain, high heat also
contribute.
Measure your RV-10 filter ensuring you subtract the 3/4" rubber seals and see what
you come up with.
Kellym wrote:
> I'm curious how you reach that conclusion. There are exactly two
> limiting orifices to the engine. One is the size of the cowling openning
> to the FAB, and the other is the fuel injection servo itself. If the alt
> air openning equals the size of the cowling opening you don't have any
> restriction. If it equals the servo opening the only loss of power would
> be from the differing flow directions and loss of ram air. The surface
> area of the filter is several multiples of either of the limiting
> openings. I doubt there is very much difference in flow through the
> factory filter and the one I had on a 370 hp Camaro Z-28 I used to drive
> and maintain(back when leaded 98 octane was available at most street
> corners) which at 7000 rpm flowed a heck of a lot more air than a 540 at
> 270 rpm will. Meaningful flow restriction by an opening only occurs when
> the pressure drop is sufficient to reach transonic speeds.
> Also, look at the filter size on many certified planes in the same power
> range and I think you will find a number that are smaller than the Vans
> supplied filter. I know the filter for my 200 hp Mooney is a whole lot
> less, and the filter bypass ram air opening is about the same size as
> the flange to the fuel servo.
> On 8/26/2014 5:21 AM, rv10flyer wrote:
>
> >
> >
> > Our factory provided air filter has barely enough surface area for a 540.
I would not want to remove 30% of its area for normal operations. Good luck with
your mod.
> >
> > --------
> > Wayne G.
> >
> >
> >
> >
> > Read this topic online here:
> >
> > http://forums.matronics.com/viewtopic.php?p=429341#429341
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
--------
Wayne G.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429357#429357
Message 8
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Wayne,
Undersized? I don't think so, but I didn't take the time to measure
mine. It's still a virgin! Cut your old one apart and spread out the
pleats to really measure the surface area.
So, how did you measure yours and what did you come up with?
I really believe the shrinking filter is the rubber ring reacting to
100LL. How many have the drain hole? My drain hole drops down into my
alt air mod keeping the filter rubber relatively dry.
Linn
On 8/26/2014 10:58 AM, rv10flyer wrote:
>
> >From K & N website...
>
> A = (C.I.D. x RPM) / 20,839
>
> A= 540 X 2,700 / 20,839
>
> A= 70 sq in.
>
> I already measured mine and it is undersized. One of the reasons many complain
of "shrinking filters". Pressure differential, fuel, oil, rain, high heat also
contribute.
>
> Measure your RV-10 filter ensuring you subtract the 3/4" rubber seals and see
what you come up with.
>
>
> Kellym wrote:
>> I'm curious how you reach that conclusion. There are exactly two
>> limiting orifices to the engine. One is the size of the cowling openning
>> to the FAB, and the other is the fuel injection servo itself. If the alt
>> air openning equals the size of the cowling opening you don't have any
>> restriction. If it equals the servo opening the only loss of power would
>> be from the differing flow directions and loss of ram air. The surface
>> area of the filter is several multiples of either of the limiting
>> openings. I doubt there is very much difference in flow through the
>> factory filter and the one I had on a 370 hp Camaro Z-28 I used to drive
>> and maintain(back when leaded 98 octane was available at most street
>> corners) which at 7000 rpm flowed a heck of a lot more air than a 540 at
>> 270 rpm will. Meaningful flow restriction by an opening only occurs when
>> the pressure drop is sufficient to reach transonic speeds.
>> Also, look at the filter size on many certified planes in the same power
>> range and I think you will find a number that are smaller than the Vans
>> supplied filter. I know the filter for my 200 hp Mooney is a whole lot
>> less, and the filter bypass ram air opening is about the same size as
>> the flange to the fuel servo.
>> On 8/26/2014 5:21 AM, rv10flyer wrote:
>>
>>>
>>>
>>> Our factory provided air filter has barely enough surface area for a 540.
I would not want to remove 30% of its area for normal operations. Good luck with
your mod.
>>>
>>> --------
>>> Wayne G.
>>>
>>>
>>>
>>>
>>> Read this topic online here:
>>>
>>> http://forums.matronics.com/viewtopic.php?p=429341#429341
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>
> --------
> Wayne G.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429357#429357
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
>
>
Message 9
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
For that formula to be meaningful it has to be tied to horsepower and a few
other things. It has to account for pleats in the filter as being part of
the surface area. It really is a formula for the area of the filter media,
not the size of the opening.
IIRC the opening in the cowling is only about 2.25 by maybe 3.5, if that.
That calculates to less than 10 sq in, more like 8. So having 70 sq in of
filter area is meaningless for this discussion since the alt air usually is
designed to bypass the filter. An Alt air opening that equals the inlet
from the cowling is more than enough. 3X3 or equivalent. is going to
provide enough air. (unless you use the wrong primer on it)
On Tue, Aug 26, 2014 at 7:58 AM, rv10flyer <wayne.gillispie@gmail.com>
wrote:
>
> >From K & N website...
>
> A = (C.I.D. x RPM) / 20,839
>
> A= 540 X 2,700 / 20,839
>
> A= 70 sq in.
>
> I already measured mine and it is undersized. One of the reasons many
> complain of "shrinking filters". Pressure differential, fuel, oil, rain,
> high heat also contribute.
>
> Measure your RV-10 filter ensuring you subtract the 3/4" rubber seals and
> see what you come up with.
>
>
> Kellym wrote:
> > I'm curious how you reach that conclusion. There are exactly two
> > limiting orifices to the engine. One is the size of the cowling openning
> > to the FAB, and the other is the fuel injection servo itself. If the alt
> > air openning equals the size of the cowling opening you don't have any
> > restriction. If it equals the servo opening the only loss of power would
> > be from the differing flow directions and loss of ram air. The surface
> > area of the filter is several multiples of either of the limiting
> > openings. I doubt there is very much difference in flow through the
> > factory filter and the one I had on a 370 hp Camaro Z-28 I used to drive
> > and maintain(back when leaded 98 octane was available at most street
> > corners) which at 7000 rpm flowed a heck of a lot more air than a 540 at
> > 270 rpm will. Meaningful flow restriction by an opening only occurs when
> > the pressure drop is sufficient to reach transonic speeds.
> > Also, look at the filter size on many certified planes in the same power
> > range and I think you will find a number that are smaller than the Vans
> > supplied filter. I know the filter for my 200 hp Mooney is a whole lot
> > less, and the filter bypass ram air opening is about the same size as
> > the flange to the fuel servo.
> > On 8/26/2014 5:21 AM, rv10flyer wrote:
> >
> > >
> > >
> > > Our factory provided air filter has barely enough surface area for a
> 540. I would not want to remove 30% of its area for normal operations. Good
> luck with your mod.
> > >
> > > --------
> > > Wayne G.
> > >
> > >
> > >
> > >
> > > Read this topic online here:
> > >
> > > http://forums.matronics.com/viewtopic.php?p=429341#429341
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
>
>
> --------
> Wayne G.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429357#429357
>
>
Message 10
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Chris and others,
What I actually had in mind was a plane parked on a ramp in a driving rain storm,
with the wind blowing a lot of water into the filter;or maybe someone "helpful"
directing a washing hose directly at the filter(!); then taking off into
clearing but cold skies. But whatever unlikely scenario, the point is that alternate
air is meant to bypass a clogged filter, and I know of no alternate air
installation that includes a filter, the logic being that whatever unlikely event
clogged the main filter could also clog a second one. Or, a small air leak
could result in that second filter slowly getting blocked by dirt. You have
to balance that against the also unlikely happenstance of sucking in a stray screw.
As to airflow, remember that the same filter in the -10 has to pass 540/360 = 1.5x
more air than in the IO-360. Tests should tell. I would suggest using an 11
month old (dirty) filter in the test, to emulate the real world.
--------
Bob Turner
RV-10 QB
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429378#429378
Message 11
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
I would suggest that the airflow difference is not the difference in
displacement, but the difference in horsepower...260/200=1.3.
We know that LOP fuel flow * 15 equals horsepower, and we know that the
ratio in round numbers is 15 air to one fuel. Thus the ratio between air
flow and horsepower is one to one and only loosely related to
displacement. The 300 hp version of the IO-540 will clearly need more
air than the 260 hp version, yet displacement is identical.
As to airflow, remember that the same filter in the -10 has to pass
540/360 = 1.5x more air than in the IO-360. Tests should tell. I would
suggest using an 11 month old (dirty) filter in the test, to emulate the
real world. -------- Bob Turner
Message 12
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Kellym wrote:
> I would suggest that the airflow difference is not the difference in
> displacement, but the difference in horsepower...260/200=1.3.
> We know that LOP fuel flow * 15 equals horsepower, and we know that the
> ratio in round numbers is 15 air to one fuel. Thus the ratio between air
> flow and horsepower is one to one and only loosely related to
> displacement. The 300 hp version of the IO-540 will clearly need more
> air than the 260 hp version, yet displacement is identical.
>
Kelly, I respectfully disagree. The higher power engines with the same displacement
get most of their extra power by having better thermodynamic efficiency (higher
compression ratios) so they get the extra power on the same fuel and air
flow. You could turn the engine off, but let it windmill, with the throttle
wide open. Every two revolutions (4 stroke) it would attempt to pump 540 cubic
inches of air out the exhaust, regardless of whether it is a 250 HP version or
a 300 HP version.
--------
Bob Turner
RV-10 QB
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429396#429396
Message 13
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Where to install pitot mast? Vans has a hole in the forward bottom skin just in
front of the spar in line with the aileron actuator bracket. given a quickbuild
wing with this skin already riveted in place and planning to install a real
pitot tube on a standard mast mount, where is best location? I think it will
have to be somewhere on the outboard bottom skin? Also, the sequence seems to
be installation of the outboard bottom skin before the aileron actuator parts.
Is there a reason for this? Seems it would be easier to get that done before
closing up the skin.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429407#429407
Message 14
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
I'm pretty sure it depends on what primer you use on your airbox and where
it's alt air door is located! :-)
-Ben
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of bob88
Sent: Tuesday, August 26, 2014 6:16 PM
Subject: RV10-List: Pitot location
Where to install pitot mast? Vans has a hole in the forward bottom skin just
in front of the spar in line with the aileron actuator bracket. given a
quickbuild wing with this skin already riveted in place and planning to
install a real pitot tube on a standard mast mount, where is best location?
I think it will have to be somewhere on the outboard bottom skin? Also, the
sequence seems to be installation of the outboard bottom skin before the
aileron actuator parts. Is there a reason for this? Seems it would be easier
to get that done before closing up the skin.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429407#429407
Message 15
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
Bob,
Your assumption of more power on equal fuel and air is simply incorrect.
While there may be small improvements in efficiency the vast majority of
the horsepower change is by getting more air and fuel through the engine.
You aren't pumping an incompressible fluid through the engine. Compression
and manifold pressure have a lot to do with the power produced and the mass
of the air passing through the engine. That is why turbo motors make more
power..they push more air and fuel through the engine while the
displacement remains the same. Not to mention that primer in military
colors produces more power.
Kelly
On Tue, Aug 26, 2014 at 4:29 PM, Bob Turner <bobturner@alum.rpi.edu> wrote:
>
>
> Kelly, I respectfully disagree. The higher power engines with the same
> displacement get most of their extra power by having better thermodynamic
> efficiency (higher compression ratios) *so they get the extra power on the
> same fuel and air flow*. You could turn the engine off, but let it
> windmill, with the throttle wide open. Every two revolutions (4 stroke) it
> would attempt to pump 540 cubic inches of air out the exhaust, regardless
> of whether it is a 250 HP version or a 300 HP version.
>
> --------
> Bob Turner
> RV-10 QB
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429396#429396
>
>
Message 16
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Trim servo question |
Vans has the aileron trim servo (Ray Allen) in the left wing and Garmin has the
GSA28 autopilot servo in the right wing. The wiring from the Ray Allen has to
pass through the Garmin servo. Has anyone put both in the same wing, or is it
better to just run wire across the fuselage?
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429417#429417
Message 17
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Pitot location |
I put mine in the next bay outboard of the aileron bracket. Made my own
mast .... because I could. I haven't riveted the bottom panel yet but
you can work through the inspection panel. I used the Van's pitot (the
hole below the bracket) with a 45 fitting for my AOA.
Linn .... final sanding the windshield fairing
On 8/26/2014 9:15 PM, bob88 wrote:
>
> Where to install pitot mast? Vans has a hole in the forward bottom skin just
in front of the spar in line with the aileron actuator bracket. given a quickbuild
wing with this skin already riveted in place and planning to install a real
pitot tube on a standard mast mount, where is best location? I think it will
have to be somewhere on the outboard bottom skin? Also, the sequence seems to
be installation of the outboard bottom skin before the aileron actuator parts.
Is there a reason for this? Seems it would be easier to get that done before
closing up the skin.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429407#429407
>
>
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
>
>
Message 18
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Pitot location |
Pitot is about half way, pretty much where Linn has his, I didnt rivet the
bottom skins until the end, pretty much when the skins where riveted
everything in the wing was installed and bolted down.I did have it clecoed
for the pitot install and fitting of tubes.
Pascal
-----Original Message-----
From: bob88
Sent: Tuesday, August 26, 2014 6:15 PM
Subject: RV10-List: Pitot location
Where to install pitot mast? Vans has a hole in the forward bottom skin just
in front of the spar in line with the aileron actuator bracket. given a
quickbuild wing with this skin already riveted in place and planning to
install a real pitot tube on a standard mast mount, where is best location?
I think it will have to be somewhere on the outboard bottom skin? Also, the
sequence seems to be installation of the outboard bottom skin before the
aileron actuator parts. Is there a reason for this? Seems it would be easier
to get that done before closing up the skin.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429407#429407
Message 19
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
It has nothing to do with HP. It is all about moving a volume of air in a certain
amount of time through the air filter. Our 540 cubic-inch engine operating
at 2700 RPM flows about 380 CFM at 90% volumetric efficiency.
>From K&N website..."Use the formula below to compute the minimum size filter required
for your particular application. The usable portion of the filter is called
the EFFECTIVE FILTERING AREA which is determined by multiplying the diameter
of the filter times Pi (3.1416) times the height of the air filter in inches,
then subtracting .75-inch. We subtract .75-inch to compensate for the rubber
seals on each end of the element and the filter material near them since very
little air flows through this area."
No, you don't stretch the pleats out before measuring. I said nothing about his
inlet or alternate air opening area. I am seeing about 30% of his EFA(Effective
Filtering Area) blocked off. This from an already marginally sized filter.
[quote="Kelly McMullen"]For that formula to be meaningful it has to be tied to
horsepower and a few other things. It has to account for pleats in the filter
as being part of the surface area. It really is a formula for the area of the
filter media, not the size of the opening.
IIRC the opening in the cowling is only about 2.25 by maybe 3.5, if that. That
calculates to less than 10 sq in, more like 8. So having 70 sq in of filter area
is meaningless for this discussion since the alt air usually is designed to
bypass the filter. An Alt air opening that equals the inlet from the cowling
is more than enough. 3X3 or equivalent. is going to provide enough air. (unless
you use the wrong primer on it)
On Tue, Aug 26, 2014 at 7:58 AM, rv10flyer wrote:
>
> >From K & N website...
>
> A = (C.I.D. x RPM) / 20,839
>
> A= 540 X 2,700 / 20,839
>
> A= 70 sq in.
>
> I already measured mine and it is undersized. One of the reasons many complain
of "shrinking filters". Pressure differential, fuel, oil, rain, high heat also
contribute.
>
> Measure your RV-10 filter ensuring you subtract the 3/4" rubber seals and see
what you come up with.
>
>
> Kellym wrote:
> > I'm curious how you reach that conclusion. There are exactly two
> > limiting orifices to the engine. One is the size of the cowling openning
> > to the FAB, and the other is the fuel injection servo itself. If the alt
> > air openning equals the size of the cowling opening you don't have any
> > restriction. If it equals the servo opening the only loss of power would
> > be from the differing flow directions and loss of ram air. The surface
> > area of the filter is several multiples of either of the limiting
> > openings. I doubt there is very much difference in flow through the
> > factory filter and the one I had on a 370 hp Camaro Z-28 I used to drive
> > and maintain(back when leaded 98 octane was available at most street
> > corners) which at 7000 rpm flowed a heck of a lot more air than a 540 at
> > 270 rpm will. Meaningful flow restriction by an opening only occurs when
> > the pressure drop is sufficient to reach transonic speeds.
> > Also, look at the filter size on many certified planes in the same power
> > range and I think you will find a number that are smaller than the Vans
> > supplied filter. I know the filter for my 200 hp Mooney is a whole lot
> > less, and the filter bypass ram air opening is about the same size as
> > the flange to the fuel servo.
> > On 8/26/2014 5:21 AM, rv10flyer wrote:
> >
> > >
> > >
> > > Our factory provided air filter has barely enough surface area for a 540.
I would not want to remove 30% of its area for normal operations. Good luck
with your mod.
> > >
> > > --------
> > > Wayne G.
> > >
> > >
> > >
> > >
> > > Read this topic online here:
> > >
> > > http://forums.matronics.com/viewtopic.php?p=429341#429341 (http://forums.matronics.com/viewtopic.php?p=429341#429341)
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> >
>
>
> --------
> Wayne G.
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429357#429357 (http://forums.matronics.com/viewtopic.php?p=429357#429357)
>
>
>
>
>
>
>
> ==========
> target="_blank">http://www.matronics.com/Navigator?RV10-List
> ==========
> ">http://forums.matronics.com
> ==========
> le, List Admin.
> ="_blank">http://www.matronics.com/contribution
> ==========
>
>
>
> [b]
--------
Wayne G.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429427#429427
Message 20
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
You also are confusing the engine's air needs. Horsepower has everything
to do with how much air moves through the engine. Displacement is only
one factor. Air is compressible, it is not a liquid, so the amount going
through the engine and out the exhaust is much more closely related to
power produced than it is to displacement.
Filter area needs have more to do with removal of dirt. It is irrelevant
with any alternate air that bypasses the filter.
You only need to consider the size of the cowl opening to know the
maximum size needed to develop rated horsepower.
With alternate air, you don't expect to get full power, but something
more like 89 percent power, just as with a carburetor you don't get full
power with carb heat.
On 8/26/2014 10:22 PM, rv10flyer wrote:
>
> It has nothing to do with HP. It is all about moving a volume of air in a certain
amount of time through the air filter. Our 540 cubic-inch engine operating
at 2700 RPM flows about 380 CFM at 90% volumetric efficiency.
>
>
> >From K&N website..."Use the formula below to compute the minimum size filter
required for your particular application. The usable portion of the filter is
called the EFFECTIVE FILTERING AREA which is determined by multiplying the diameter
of the filter times Pi (3.1416) times the height of the air filter in inches,
then subtracting .75-inch. We subtract .75-inch to compensate for the rubber
seals on each end of the element and the filter material near them since
very little air flows through this area."
>
> No, you don't stretch the pleats out before measuring. I said nothing about his
inlet or alternate air opening area. I am seeing about 30% of his EFA(Effective
Filtering Area) blocked off. This from an already marginally sized filter.
>
> [quote="Kelly McMullen"]For that formula to be meaningful it has to be tied to
horsepower and a few other things. It has to account for pleats in the filter
as being part of the surface area. It really is a formula for the area of the
filter media, not the size of the opening.
> IIRC the opening in the cowling is only about 2.25 by maybe 3.5, if that. That
calculates to less than 10 sq in, more like 8. So having 70 sq in of filter
area is meaningless for this discussion since the alt air usually is designed
to bypass the filter. An Alt air opening that equals the inlet from the cowling
is more than enough. 3X3 or equivalent. is going to provide enough air. (unless
you use the wrong primer on it)
>
>
>
> On Tue, Aug 26, 2014 at 7:58 AM, rv10flyer wrote:
>
>>
>> >From K & N website...
>>
>> A = (C.I.D. x RPM) / 20,839
>>
>> A= 540 X 2,700 / 20,839
>>
>> A= 70 sq in.
>>
>> I already measured mine and it is undersized. One of the reasons many complain
of "shrinking filters". Pressure differential, fuel, oil, rain, high heat
also contribute.
>>
>> Measure your RV-10 filter ensuring you subtract the 3/4" rubber seals and
see what you come up with.
>>
>>
>> Kellym wrote:
>> > I'm curious how you reach that conclusion. There are exactly two
>> > limiting orifices to the engine. One is the size of the cowling openning
>> > to the FAB, and the other is the fuel injection servo itself. If the alt
>> > air openning equals the size of the cowling opening you don't have any
>> > restriction. If it equals the servo opening the only loss of power would
>> > be from the differing flow directions and loss of ram air. The surface
>> > area of the filter is several multiples of either of the limiting
>> > openings. I doubt there is very much difference in flow through the
>> > factory filter and the one I had on a 370 hp Camaro Z-28 I used to drive
>> > and maintain(back when leaded 98 octane was available at most street
>> > corners) which at 7000 rpm flowed a heck of a lot more air than a 540 at
>> > 270 rpm will. Meaningful flow restriction by an opening only occurs when
>> > the pressure drop is sufficient to reach transonic speeds.
>> > Also, look at the filter size on many certified planes in the same power
>> > range and I think you will find a number that are smaller than the Vans
>> > supplied filter. I know the filter for my 200 hp Mooney is a whole lot
>> > less, and the filter bypass ram air opening is about the same size as
>> > the flange to the fuel servo.
>> > On 8/26/2014 5:21 AM, rv10flyer wrote:
>> >
>> > >
>> > >
>> > > Our factory provided air filter has barely enough surface area for a 540.
I would not want to remove 30% of its area for normal operations. Good luck
with your mod.
>> > >
>> > > --------
>> > > Wayne G.
>> > >
>> > >
>> > >
>> > >
>> > > Read this topic online here:
>> > >
>> > > http://forums.matronics.com/viewtopic.php?p=429341#429341 (http://forums.matronics.com/viewtopic.php?p=429341#429341)
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> > >
>> >
>>
>>
>> --------
>> Wayne G.
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=429357#429357 (http://forums.matronics.com/viewtopic.php?p=429357#429357)
>>
>>
>>
>>
>>
>>
>>
>> ==========
>> target="_blank">http://www.matronics.com/Navigator?RV10-List
>> ==========
>> ">http://forums.matronics.com
>> ==========
>> le, List Admin.
>> ="_blank">http://www.matronics.com/contribution
>> ==========
>>
>>
>>
>> [b]
>
> --------
> Wayne G.
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429427#429427
>
>
Message 21
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
| Subject: | Re: Pitot location |
The most important thing to keep in mind in pitot location is to keep it outside
of the propeller arc. You don't want to be measuring the speed of the air the
propeller pushes.
On Aug 26, 2014, at 21:00, "Pascal" <rv10flyer@live.com> wrote:
>
> Pitot is about half way, pretty much where Linn has his, I didnt rivet the bottom
skins until the end, pretty much when the skins where riveted everything
in the wing was installed and bolted down.I did have it clecoed for the pitot
install and fitting of tubes.
> Pascal
>
> -----Original Message----- From: bob88
> Sent: Tuesday, August 26, 2014 6:15 PM
> To: rv10-list@matronics.com
> Subject: RV10-List: Pitot location
>
>
> Where to install pitot mast? Vans has a hole in the forward bottom skin just
in front of the spar in line with the aileron actuator bracket. given a quickbuild
wing with this skin already riveted in place and planning to install a real
pitot tube on a standard mast mount, where is best location? I think it will
have to be somewhere on the outboard bottom skin? Also, the sequence seems to
be installation of the outboard bottom skin before the aileron actuator parts.
Is there a reason for this? Seems it would be easier to get that done before
closing up the skin.
>
>
>
>
> Read this topic online here:
>
> http://forums.matronics.com/viewtopic.php?p=429407#429407
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Message 22
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
The simple formula that K&N provides gives us a MINIMUM filter area for our simple
engine. Our filter is undersized according to their formula. Undersized filters
equal higher air velocities, greater pressure drop and less efficient filtering.
I am not an engineer and it is his airplane.
[quote="Kellym"]You also are confusing the engine's air needs. Horsepower has everything
to do with how much air moves through the engine. Displacement is only
one factor. Air is compressible, it is not a liquid, so the amount going
through the engine and out the exhaust is much more closely related to
power produced than it is to displacement.
Filter area needs have more to do with removal of dirt. It is irrelevant
with any alternate air that bypasses the filter.
You only need to consider the size of the cowl opening to know the
maximum size needed to develop rated horsepower.
With alternate air, you don't expect to get full power, but something
more like 89 percent power, just as with a carburetor you don't get full
power with carb heat.
On 8/26/2014 10:22 PM, rv10flyer wrote:
>
>
> It has nothing to do with HP. It is all about moving a volume of air in a certain
amount of time through the air filter. Our 540 cubic-inch engine operating
at 2700 RPM flows about 380 CFM at 90% volumetric efficiency.
>
>
> >From K&N website..."Use the formula below to compute the minimum size filter
required for your particular application. The usable portion of the filter is
called the EFFECTIVE FILTERING AREA which is determined by multiplying the diameter
of the filter times Pi (3.1416) times the height of the air filter in
inches, then subtracting .75-inch. We subtract .75-inch to compensate for the
rubber seals on each end of the element and the filter material near them since
very little air flows through this area."
>
> No, you don't stretch the pleats out before measuring. I said nothing about
his inlet or alternate air opening area. I am seeing about 30% of his EFA(Effective
Filtering Area) blocked off. This from an already marginally sized filter.
>
>
> Kelly McMullen wrote:
> > For that formula to be meaningful it has to be tied to horsepower and a few
other things. It has to account for pleats in the filter as being part of the
surface area. It really is a formula for the area of the filter media, not the
size of the opening.
> > IIRC the opening in the cowling is only about 2.25 by maybe 3.5, if that.
That calculates to less than 10 sq in, more like 8. So having 70 sq in of filter
area is meaningless for this discussion since the alt air usually is designed
to bypass the filter. An Alt air opening that equals the inlet from the cowling
is more than enough. 3X3 or equivalent. is going to provide enough air.
(unless you use the wrong primer on it)
> >
> >
> >
> >
> > On Tue, Aug 26, 2014 at 7:58 AM, rv10flyer wrote:
> >
> > >
> > >
> > > >From K & N website...
> > >
> > > A = (C.I.D. x RPM) / 20,839
> > >
> > > A= 540 X 2,700 / 20,839
> > >
> > > A= 70 sq in.
> > >
> > > I already measured mine and it is undersized. One of the reasons many complain
of "shrinking filters". Pressure differential, fuel, oil, rain, high heat
also contribute.
> > >
> > > Measure your RV-10 filter ensuring you subtract the 3/4" rubber seals and
see what you come up with.
> > >
> > >
> > > Kellym wrote:
> > > > I'm curious how you reach that conclusion. There are exactly two
> > > > limiting orifices to the engine. One is the size of the cowling openning
> > > > to the FAB, and the other is the fuel injection servo itself. If the
alt
> > > > air openning equals the size of the cowling opening you don't have any
> > > > restriction. If it equals the servo opening the only loss of power would
> > > > be from the differing flow directions and loss of ram air. The surface
> > > > area of the filter is several multiples of either of the limiting
> > > > openings. I doubt there is very much difference in flow through the
> > > > factory filter and the one I had on a 370 hp Camaro Z-28 I used to drive
> > > > and maintain(back when leaded 98 octane was available at most street
> > > > corners) which at 7000 rpm flowed a heck of a lot more air than a 540
at
> > > > 270 rpm will. Meaningful flow restriction by an opening only occurs when
> > > > the pressure drop is sufficient to reach transonic speeds.
> > > > Also, look at the filter size on many certified planes in the same power
> > > > range and I think you will find a number that are smaller than the Vans
> > > > supplied filter. I know the filter for my 200 hp Mooney is a whole lot
> > > > less, and the filter bypass ram air opening is about the same size as
> > > > the flange to the fuel servo.
> > > > On 8/26/2014 5:21 AM, rv10flyer wrote:
> > > >
> > > > >
> > > > >
> > > > > Our factory provided air filter has barely enough surface area for
a 540. I would not want to remove 30% of its area for normal operations. Good
luck with your mod.
> > > > >
> > > > > --------
> > > > > Wayne G.
> > > > >
> > > > >
> > > > >
> > > > >
> > > > > Read this topic online here:
> > > > >
> > > > > http://forums.matronics.com/viewtopic.php?p=429341#429341 (http://forums.matronics.com/viewtopic.php?p=429341#429341)
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > > >
> > > >
> > >
> > >
> > > --------
> > > Wayne G.
> > >
> > >
> > >
> > >
> > > Read this topic online here:
> > >
> > > http://forums.matronics.com/viewtopic.php?p=429357#429357 (http://forums.matronics.com/viewtopic.php?p=429357#429357)
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > ==========
> > > target="_blank">http://www.matronics.com/Navigator?RV10-List
> > > ==========
> > > ">http://forums.matronics.com
> > > ==========
> > > le, List Admin.
> > > ="_blank">http://www.matronics.com/contribution
> > > ==========
> > >
> > >
> > >
> > > [b]
> >
> > --------
> > Wayne G.
> >
> >
> >
> >
> > Read this topic online here:
> >
> > http://forums.matronics.com/viewtopic.php?p=429427#429427
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
>
--------
Wayne G.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429431#429431
Message 23
| INDEX | Back to Main INDEX |
| PREVIOUS | Skip to PREVIOUS Message |
| NEXT | Skip to NEXT Message |
| LIST | Reply to LIST Regarding this Message |
| SENDER | Reply to SENDER Regarding this Message |
|
So let's all agree that knowing the exact answer is hard; getting an approximate
answer can be had in various ways.
For a slow turning engine it's just displacement times RPM.
For a real engine, the efficiency of the intake valves can be a 10 - 20% factor,
so maybe we should use power. But timing and compression ratios can affect power
without changing the air flow, so that's not perfect either.
But either method should get you close.
--------
Bob Turner
RV-10 QB
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=429432#429432
Other Matronics Email List Services
These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.
-- Please support this service by making your Contribution today! --
|