Today's Message Index:
----------------------
1. 05:03 AM - Re: Dual Lightspeed? (Marcus Cooper)
2. 05:55 AM - Re: Re: Dual Lightspeed? ()
3. 06:39 AM - Re: Vne and flutter (was engines) (ivo welch)
4. 07:22 AM - Re: Dual Lightspeed? (Stewart, Michael (ISS Atlanta))
5. 07:22 AM - Re: Re: engines (Nikolaos Napoli)
6. 08:11 AM - Mags vs electronic ignition (Chris Hukill)
7. 10:06 AM - Re: Dual Lightspeed? (Bill DeRouchey)
8. 10:58 AM - Re: Dual Lightspeed? (Tim Olson)
9. 11:33 AM - Re: Dual Lightspeed? (LessDragProd@aol.com)
10. 11:36 AM - Re: Dual Lightspeed? (Chris Johnston)
11. 12:35 PM - Re: engines (Billy)
12. 12:51 PM - Re: Mags vs electronic ignition (John Hasbrouck)
13. 01:30 PM - O-540-A1D5 (Phillips, Jack)
14. 05:03 PM - Re: Dual Lightspeed? (John W. Cox)
15. 08:37 PM - Re: Re: engines ()
Message 1
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| Subject: | Dual Lightspeed? |
One last (probably not) consideration for you aside from the redundancy
issues. When I was looking at the Lightspeed options, I talked to Klaus and
he indicated about 90% of the performance advantages are obtained with the
first system and there is a limited performance increase by using dual
electronic ignition systems. Since I had not already put in the dual
alternator/battery setup I opted for a Lightspeed/standard mag setup. My
only backup battery is in the Dynon EFIS I use as the standby instrument.
Marcus
40286
60 hours and loving it
_____
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Chris Johnston
Sent: Thursday, October 19, 2006 1:38 PM
Subject: RV10-List: Dual Lightspeed?
Hey all -
Sorry if this has been discussed already, but I combed the archives and
couldn't really find what I was looking for. I've got a couple opinions
privately, but thought I'd pose the question to the list. I'm getting ready
to order an engine, and originally I thought I'd go dual lightspeed
ignition, but as I get closer, I'm starting to chicken out and am thinking
of going single lightspeed / slick mag. The aircraft is all electric, dual
battery, and 2 alternators ( main, and SD-8 as standby). Can I get a few
people to weigh in?
Thanks
cj
#40410
fuse
www.perfectlygoodairplane.net <http://www.perfectlygoodairplane.net/>
(updated!!)
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of GRANSCOTT@aol.com
Sent: Thursday, October 19, 2006 7:38 AM
Subject: Re: RV10-List: Re: engines
Thanks, Kelly...enjoy the rest of your trip...
P
- The RV10-List Email Forum -
--> http://www.matronics.com/Navigator?RV10-List
- NEW MATRONICS WEB FORUMS -
-->
- NEW MATRONICS LIST WIKI -
-->
- List Contribution Web Site -
Thank you for your generous support!
-Matt Dralle, List Admin.
-->
Message 2
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| Subject: | Re: Dual Lightspeed? |
--> RV10-List message posted by: <gorejr@bellsouth.net>
Talk to Rhonda at Barrett. I think you might consider changing your mind about
using these systems. These folks are in the experience loop! They deal with
these issues daily. Jim
>
> From: "John W. Cox" <johnwcox@pacificnw.com>
> Date: 2006/10/19 Thu PM 11:10:22 EDT
> To: <rv10-list@matronics.com>
> Subject: RE: RV10-List: Dual Lightspeed?
>
> Chris, this is an excellent discussion point but be sure and evaluate
> all the characteristics. By reading today's posts, most of the
> decisions were a "I follow the leader" mentality. "I don't know why but
> the crowd is moving towards the noise. So I guess I should follow" A
> responsible solution is to study the characteristics, ask experienced
> operators, weigh the pluses and minuses. That means make a list.
>
>
>
> At this time the six cylinder P Mag is not yet an alternative. It
> merits review. The GAMI supplenator and PRISM are not yet to market.
> The magneto and electronic ignition systems are. Do not limit your
> knowledge input.
>
>
>
> Which performs better at idle?
>
> Which assists in resisting Lead Fowling of your plugs?
>
> Which makes use of automotive plugs rather than aviation?
>
> Which is more reliable?
>
> Which is more cost effective over its entire life?
>
> Which is easier to maintain on the road when traveling distances from
> your maintenance base?
>
> Which produces more horsepower and performance in the range requests by
> the pilot?
>
> Which works better at altitude?
>
> Which does not change spark advance over the range of load, F/A
> temperature and rpm?
>
> What is Flame Front Propagation and why does it require a change in
> spark advance to maintain BMP?
>
> Which system will respond better to an alternative fuel to 100LL?
>
> Which one is less prone to failure and ensuing safety concerns?
>
>
>
> Your work is not done. Before you reach a conclusion, ask the pros. You
> will likely get a choir of similar answers here which might not qualify
> the value of the answer enough. This input has not yet been
> comprehensively tabulated. In the lack of a conclusion on the subject.
> My source is Barrett. The dyno says HP drop with dual electronics.
> Research the why and the negatives before throwing out the baby with the
> bath water.
>
>
>
> John W. Cox
>
> #40600
>
> Do not Archive until all of the meaningful input is recorded.
>
>
>
> ________________________________
>
> From: owner-rv10-list-server@matronics.com
> [mailto:owner-rv10-list-server@matronics.com] On Behalf Of Chris
> Johnston
> Sent: Thursday, October 19, 2006 10:38 AM
> To: rv10-list@matronics.com
> Subject: RV10-List: Dual Lightspeed?
>
>
>
> Hey all -
>
>
>
> Sorry if this has been discussed already, but I combed the archives and
> couldn't really find what I was looking for. I've got a couple opinions
> privately, but thought I'd pose the question to the list. I'm getting
> ready to order an engine, and originally I thought I'd go dual
> lightspeed ignition, but as I get closer, I'm starting to chicken out
> and am thinking of going single lightspeed / slick mag. The aircraft
> is all electric, dual battery, and 2 alternators ( main, and SD-8 as
> standby). Can I get a few people to weigh in?
>
>
>
> Thanks
>
> cj
>
> #40410
>
> fuse
>
> www.perfectlygoodairplane.net <http://www.perfectlygoodairplane.net/>
> (updated!!)
>
>
>
> -----Original Message-----
> From: owner-rv10-list-server@matronics.com
> [mailto:owner-rv10-list-server@matronics.com] On Behalf Of
> GRANSCOTT@aol.com
> Sent: Thursday, October 19, 2006 7:38 AM
> To: rv10-list@matronics.com
> Subject: Re: RV10-List: Re: engines
>
>
>
> Thanks, Kelly...enjoy the rest of your trip...
>
>
>
> P
>
>
>
>
> - The RV10-List Email Forum -
> --> http://www.matronics.com/Navigator?RV10-List
>
> - NEW MATRONICS WEB FORUMS -
> -->
>
> - NEW MATRONICS LIST WIKI -
> -->
>
> - List Contribution Web Site -
> Thank you for your generous support!
> -Matt Dralle, List Admin.
> -->
>
>
>
>
>
>
>
Message 3
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| Subject: | Re: Vne and flutter (was engines) |
--> RV10-List message posted by: ivo welch <ivowel@gmail.com>
I am not an expert, but Vans seems to be very conservative when it comes
to such issues as specifications, Vne, etc. It would not surprise me if
there is some wiggle room. Alas, I would feel more comfortable with a
ballistic parachute if I were to try to exceed Vne on a semi-regular
basis. An airplane, even an RV-10, is replaceable---you are not.
I have a 325hp engine of in my aircraft, which is really only the 260hp
engine fine-tuned a little bit better. I have not flown the 260hp
engine, but from what I have observed in flight, the difference in
performance seems to be very small. A turbo at high altitude, however,
might make a real difference. of course, you then need oxygen, too. It
becomes a much more complex (and potentially pilot-exhausting)
exercise. with a parachute, this could be a nice thing to do, so.
PS: n325hp is still for sale, now at the reduced price of $209,000.
regards,
/iaw
Message 4
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| Subject: | Dual Lightspeed? |
--> RV10-List message posted by: "Stewart, Michael (ISS Atlanta)" <mstewart@iss.net>
I had dual hall effects in my 6.
Have Direct crank in my 8.
Mike
Do not archive.
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Tim Olson
Sent: Thursday, October 19, 2006 3:39 PM
Subject: Re: RV10-List: Dual Lightspeed?
--> RV10-List message posted by: Tim Olson <Tim@MyRV10.com>
I see Mike Stewart also replied that he sees no problems.
One thing to be aware of is that Mike probably has the
rear mounted hall effect sensors (or am I wrong, Mike?),
so it isn't the same as the IO-540 crank sensor mount.
Bob's got a good idea of separate routing. I was also
*slightly* personally worried about the fragility of
the electronics up under that hub...and about the
what-if's during bad weather, or even lightning/static
discharge. Again, I'm not saying "don't do it"...just
giving my rationalization. I'm just as swayed to go
dual electronic some day...I just don't quite yet have
the nads required. At least it runs great with just
one, or I'd be just diving right into it.
Tim Olson - RV-10 N104CD - Flying
do not archive
Condrey, Bob (US SSA) wrote:
> Chris,
>
>
>
> I opted for dual LSE Plasma IIIs and have dual alternators and
> electrical busses. The point that Tim makes is a valid one - the
wiring
> from the crank sensor must be very well routed/secured. With the dual
> system there's a pair of cables but they are running together. I
> suppose one could route one down each side of the engine to provide
> isolation in case of some sort of mechanical event that damage them.
>
>
>
> Bob
>
>
Message 5
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|
Hi John=0A=0AI do in general agree with you thats why I made the statement
=0A "I think part of the problem with the many of the academic articles is
that they are trying to calculate maximum range irregardless of what powe
r an engine can operate at."=0A=0AAn engine has to operate at probably the
20% to 40% power range at low altitude to get equivalent range, which I bel
ieve is not advisable with our current crop of engines. Partly due too low
engine temperatures and partly due to there not being enough fuel to get a
good even fuel./ air mixture for efficient combustion. So from a practica
l point of view, for maximum range, you set the minimum power thats advisab
le to operate the engine at which in turn sets your fuel burn. So in the R
V10 case I believe that for max range your power setting turns out to be th
e same for all altitudes which is say around 45 to 50%. At that point you
have to climb to get better range.=0A=0AThe article in the link is interest
ing and I have read several similar articles in the past as this question h
ad preplexed me for a while. They all reached the same conclusion because
they are not accounting for the specific operating requirements of the engi
nes.=0A=0ABest regards and thanks for your input as I don't fully understa
nd all this.=0A =0ANiko=0A=0A=0A=0A----- Original Message ----=0AFrom: John
Ackerman <johnag5b@cableone.net>=0ATo: rv10-list@matronics.com=0ASent: Thu
rsday, October 19, 2006 10:55:34 PM=0ASubject: Re: RV10-List: Re: engines
=0A=0A=0A--> RV10-List message posted by: John Ackerman <johnag5b@cableone.
net>=0A=0ANiko, here's the deal as I see it:=0A=0A For maximum range, th
e airplane must be flown at the airspeed/AOA for =0Aminimum drag. That spee
d increases with altitude, although the minimum =0Adrag remains pretty much
constant. The minimum power required increases =0Adirectly with the speed,
i.e. power equals speed times drag. The speed =0Avs. altitude data you pre
sent below are at _constant_power_, and for =0Athat condition, you are cert
ainly correct. The reason for the speed =0Aincrease is that at the higher a
ltitudes, the speed more closely =0Aapproximates the speed for minimum drag
.=0A=0A Constant power is not the maximum range condition, though. For m
aximum =0Arange, the power is really low for most prop/recip aircraft ' w
ell =0Abelow 50% at lower altitudes ' and it increases with altitude at t
he =0Asame rate that the speed does - hence constant max range with altitud
e. =0AAgain, the range numbers presented below reflect the fact that at =0A
higher altitude the plane is being operated closer to the ideal =0AAOA/airs
peed for minimum drag.=0A=0A Yep, it takes energy (fuel) to climb to alt
itude, but if you fly =0Aright, you get it back when you descend.=0A=0A
There's a really good reason for flying higher if you want range - =0Amany
of us are range limited by our physiological needs, and at =0Aaltitude you
get the same miles/gallon and range, but at a higher =0Aspeed, so you can g
o farther before your body (or your passenger's =0Abody) dictates a landing
.=0A=0AAll this stuff assumes constant engine efficiency. That approximatio
n =0Ais way better than the errors induced by my stick skills - maybe even
=0Amost folks' skills. It also assumes still air, but that's another story
=0Aentirely.=0A=0ABest wishes,=0AJohn Ackerman=0A=0A=0AOn Oct 19, 2006, at
2:58 PM, Nikolaos Napoli wrote:=0A=0A> Well I just looked at the Cessna 172
S POH=0A> for standard day=0A> =0A> at 2000 ft 73% BHP 9.9 gph 115 KTA
S=0A> at 4000 ft 73% BHP 9.9 gph 117 KTAS=0A> at 6000 ft 73% BHP 9.9 gp
h 119 KTAS=0A> =0A> For the same fuel flow at higher altitude you get a
higher speed thus =0A> a longer range.=0A> =0A> This is clearly depicted i
n the range curve of the 172s POH (Figure =0A> 5-9).=0A> =0A> at 55% power
=0A> at sea level 585 miles 101 KTAS=0A> at 120000 ft 605 miles 110 KT
AS=0A> =0A> I think part of the problem with the many of the academic arti
cles is =0A> that they are trying to calculate maximum range irregardless o
f what =0A> power an engine can operate at. If you set power to a certain
level =0A> as 70% than the higher altitude will get you a better =0A> range
. Obviously this does not acount for fuel burn to clim.=0A> =0A> Niko=0A>
=0A>=0A> ----- Original Message ----=0A> From: John Ackerman <johnag5b@cabl
eone.net>=0A> To: Nikolaos Napoli <owl40188@yahoo.com>=0A> Sent: Thursday,
October 19, 2006 12:08:17 PM=0A> Subject: Re: RV10-List: Re: engines=0A>=0A
> Niko '=0A> Here's another take on it.=0A>=0A> http://selair.selkirk.b
c.ca/aerodynamics1/Performance/Page7.html=0A>=0A> Counterintuitive, ain't i
t?=0A> John=0A>=0A> On Oct 18, 2006, at 2:23 PM, Nikolaos Napoli wrote:=0A>
=0A> > John,=0A> > =0A> > I think Jesse is correct. You get a longer rang
e at altitude. Look=0A> > at it this way, if your true speed increases wit
h altitude the only=0A> > way your range could stay the same is if you are
burning more fuel =0A> for=0A> > the same power setting. I don't think tha
ts the case. Range and=0A> > speed both increase because the total drag is
a bit less due to the=0A> > less dense air.=0A> > =0A> >=0A> > Niko=0A> >
=0A> > 40188=0A> >=0A> >=0A> > ----- Original Message ----=0A> > From: Jess
e Saint <jesse@itecusa.org>=0A> > To: rv10-list@matronics.com=0A> > Sent: W
ednesday, October 18, 2006 1:44:59 PM=0A> > Subject: RE: RV10-List: Re: eng
ines=0A> >=0A> > --> RV10-List message posted by: "Jesse Saint" <jesse@itec
usa.org>=0A> >=0A> > I don't know about thermodynamic analysis and all that
, but when we =0A> go=0A> > high,=0A> > we go further on a tank of gas. Ma
ybe it is just the issue of being=0A> > able to=0A> > more safely go LOP on
the mixture, which obviously makes some=0A> > difference,=0A> > which you
can't/shouldn't do at high power settings. I would have to=0A> > stank=0A>
> with whoever you quoted on this one, based on experience. But, I=0A> >
don't use=0A> > experience to establish truth, just to illustrate it, so I
could=0A> > certainly=0A> > be wrong based on my experience.=0A> >=0A> > Do
not archive.=0A> >=0A> > Jesse Saint=0A> > I-TEC, Inc.=0A> > jesse@itecusa
.org=0A> > www.itecusa.org=0A> > W: 352-465-4545=0A> > C: 352-427-0285=0A>
>=0A> > -----Original Message-----=0A> > From: owner-rv10-list-server@matro
nics.com=0A> > [mailto:owner-rv10-list-server@matronics.com] On Behalf Of J
ohn=0A> > Ackerman=0A> > Sent: Wednesday, October 18, 2006 1:18 PM=0A> > To
: rv10-list@matronics.com=0A> > Subject: Re: RV10-List: Re: engines=0A> >
=0A> > --> RV10-List message posted by: John Ackerman =0A> <johnag5b@cableo
ne.net>=0A> >=0A> >=0A> >=0A> > > The easiest way to get economy is to fly
higher (to a point), and=0A> > > go LOP on the mixture.=0A> >=0A> > OK =97
flamesuit on =97=0A> > Respectfully disagree. Somebody from Embry-Riddle F
lorida once (4-5=0A> > years ago?) posted a cogent argument that still air
range is pretty=0A> > much independent of altitude and dependent only on po
wer setting. =0A> I've=0A> > lost the reference, but I did a crude thermody
namic analysis and sure=0A> > enough, got the same result. I'm way too lazy
to repeat the analysis=0A> > unless forced.=0A> >=0A> > What altitude gets
you is more speed at the same range.=0A> >=0A> > John Ackerman=0A> >=0A> >
=0A> >=0A> >=0A> >=0A> >=0A> > --=0A> >=0A> >=0A> > -- - The RV10-L
ist Email Forumavigator?RV10-List"=0A> > target=_blank>http://www.matroni
cs.com/Navigator?RV10sp; -=0A> > NEW MATRON/" "http://wiki.matroni
cs.com/";;=0A> > target=_blank>http://wiki.matronics.com< - List C
ontribution=0A> > Web Site nbsp; - The RV10-List A =0A> href="htt
p://www.matronics.com/Navigator?RV10-List"; target=_blank =0A> relp;
- NEW MATRONICS WEB FORUMtarget=_blank p; - NEW =0A> MATRONICS LI
=========
Message 6
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| Subject: | Mags vs electronic ignition |
Please allow me to chime in on this issue.
Last week while preparing for takeoff in a friends Cirrus SR22, we began
to see and smell smoke in the cockpit. Within only a couple of seconds,
we had a face full of electrical smoke. We quickly shut off both the
batteries and alternators and opened the doors and began coughing. It
turned out the culprit was a "number two battery control relay circuit
board" which is located in the cockpit that fried.
Guess what....
the engine kept running
Although my 10 will have a dual electrical system, with dual
alternators, it certainly will have at least one mag!
You just don't have enough time to troubleshoot and isolate electrical
problems when the smoke starts, especially when you can't see or breath.
Chris Hukill
Message 7
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| Subject: | Dual Lightspeed? |
I have a question for those familiar with Lightspeed (etc) ignition systems that
I have been pondering for some time. Purchased a 25 SFOH engine with new mags
and saw no good reason to upgrade. One mag was equipped with dual points "flash
of sparks" and added a SlickStart in place of the old Bendix vibrator. It
starts easily.
If you configure a system with Lightspeed and a Slick mag I would assume that
the Lightspeed is firing at 25 degrees advanced up to 45 degrees while the Slick
mag is always firing at 25 degrees. So what is happening to the force of the
gas explosion?
I cannot imagine that the Slick is contributing to the ignition if the Lightspeed
is advanced beyond 25 degrees. Therefore, does the single, hotter Lightspeed
spark create more explosive force than two mags firing at 25 degrees? Is this
the root of the cruising performance gain?
From Lycoming, setting the mags at 25 degrees, I would assume this is optimum.
What is gained when advanced beyond this point? How would the cockpit controlled
variable timing be used strategically? Do we have firm evidence that a Lightspeed/mag
configuration produces more horsepower than two mags?
I understand the ease of starting argument but need more facts to understand
the claim of higher cruise performance.
Thanks,
Bill DeRouchey
billderou@yahoo.com
flying
do not archive
"Stewart, Michael (ISS Atlanta)" <mstewart@iss.net> wrote:
--> RV10-List message posted by: "Stewart, Michael (ISS Atlanta)"
I had dual hall effects in my 6.
Have Direct crank in my 8.
Mike
Do not archive.
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Tim Olson
Sent: Thursday, October 19, 2006 3:39 PM
Subject: Re: RV10-List: Dual Lightspeed?
--> RV10-List message posted by: Tim Olson
I see Mike Stewart also replied that he sees no problems.
One thing to be aware of is that Mike probably has the
rear mounted hall effect sensors (or am I wrong, Mike?),
so it isn't the same as the IO-540 crank sensor mount.
Bob's got a good idea of separate routing. I was also
*slightly* personally worried about the fragility of
the electronics up under that hub...and about the
what-if's during bad weather, or even lightning/static
discharge. Again, I'm not saying "don't do it"...just
giving my rationalization. I'm just as swayed to go
dual electronic some day...I just don't quite yet have
the nads required. At least it runs great with just
one, or I'd be just diving right into it.
Tim Olson - RV-10 N104CD - Flying
do not archive
Condrey, Bob (US SSA) wrote:
> Chris,
>
>
>
> I opted for dual LSE Plasma IIIs and have dual alternators and
> electrical busses. The point that Tim makes is a valid one - the
wiring
> from the crank sensor must be very well routed/secured. With the dual
> system there's a pair of cables but they are running together. I
> suppose one could route one down each side of the engine to provide
> isolation in case of some sort of mechanical event that damage them.
>
>
>
> Bob
>
>
Message 8
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| Subject: | Re: Dual Lightspeed? |
--> RV10-List message posted by: Tim Olson <Tim@MyRV10.com>
Bill DeRouchey wrote:
> I have a question for those familiar with Lightspeed (etc) ignition
> systems that I have been pondering for some time. Purchased a 25 SFOH
> engine with new mags and saw no good reason to upgrade. One mag
> was equipped with dual points "flash of sparks" and added a SlickStart
> in place of the old Bendix vibrator. It starts easily.
>
> If you configure a system with Lightspeed and a Slick mag I would assume
> that the Lightspeed is firing at 25 degrees advanced up to 45 degrees
> while the Slick mag is always firing at 25 degrees. So what is happening
> to the force of the gas explosion?
>
I'm not sure of the lowest lightspeed advance setting, but it may be
well below 25. Remember that mags are set at 25 for the best
cruise setting. The lightspeed can very depending on the
power setting, both MP and RPM.
> I cannot imagine that the Slick is contributing to the ignition if the
> Lightspeed is advanced beyond 25 degrees. Therefore, does the single,
> hotter Lightspeed spark create more explosive force than two mags firing
> at 25 degrees? Is this the root of the cruising performance gain?
>
I'm sure it's still contributing, just not as much. You still get
the burn from the other side of the cylinder somewhat. I don't think
there's any change in explosive force, just a hotter spark that ignites
quicker. I think you will find there is an argument as to whether or
not there is a performance gain, or a loss...there are arguments on
both sides.
> From Lycoming, setting the mags at 25 degrees, I would assume this is
> optimum. What is gained when advanced beyond this point? How would the
> cockpit controlled variable timing be used strategically? Do we have
> firm evidence that a Lightspeed/mag configuration produces more
> horsepower than two mags?
I think you can gain some fuel efficiency. I would not recommend
the cockpit controlled variable timing. I don't know that there is
any firm evidence of power increase with Lightspeed/mag. I
do know that the Lightspeed equipped engines I've heard are
considerably smoother sounding than engines with only mags.
It's the fuel economy and smoothness that lead me to them.
Keep in mind that one of the other huge benefits is the lightspeed
will keep your plugs cleaner and let you use cheaper auto plugs.
In my previous plane, I was FORCED to clean the plugs...actually
remove them and pick out the lead and scale, every 25-50 hours,
even though I leaned aggressively. On my new engine, it ran
smooth so I didn't pull the plugs until 70 hours...and then after
checking the front 4, I stuck them back in because they were
perfect, and skipped the rest. Now, at 170 hours, it still
runs great, and soon I'll pull them again just to see how
it's looking.
>
> I understand the ease of starting argument but need more facts to
> understand the claim of higher cruise performance.
>
I wouldn't bet on the performance aspect.
Tim
> Thanks,
> Bill DeRouchey
> billderou@yahoo.com <mailto:billderou@yahoo.com>
> flying
> do not archive
>
>
> */"Stewart, Michael (ISS Atlanta)" <mstewart@iss.net>/* wrote:
>
> --> RV10-List message posted by: "Stewart, Michael (ISS Atlanta)"
>
> I had dual hall effects in my 6.
> Have Direct crank in my 8.
> Mike
> Do not archive.
>
>
> -----Original Message-----
> From: owner-rv10-list-server@matronics.com
> [mailto:owner-rv10-list-server@matronics.com] On Behalf Of Tim Olson
> Sent: Thursday, October 19, 2006 3:39 PM
> To: rv10-list@matronics.com
> Subject: Re: RV10-List: Dual Lightspeed?
>
> --> RV10-List message posted by: Tim Olson
>
> I see Mike Stewart also replied that he sees no problems.
> One thing to be aware of is that Mike probably has the
> rear mounted hall effect sensors (or am I wrong, Mike?),
> so it isn't the same as the IO-540 crank sensor mount.
> Bob's got a good idea of separate routing. I was also
> *slightly* personally worried about the fragility of
> the electronics up under that hub...and about the
> what-if's during bad weather, or even lightning/static
> discharge. Again, I'm not saying "don't do it"...just
> giving my rationalization. I'm just as swayed to go
> dual electronic some
>
> *
>
>
> *
Message 9
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| Subject: | Re: Dual Lightspeed? |
Just my opinion:
The hotter Lightspeed spark fires five (5) times during each combustion
stroke.
The magneto "25 degree" spark advance is a single point setting that is
"always safe" for the harshest power setting. It is NOT optimized for a normal
cruise power setting.
Regards,
Jim Ayers
In a message dated 10/20/2006 10:08:16 AM Pacific Daylight Time,
billderou@yahoo.com writes:
(Stuff Cut)
Therefore, does the single, hotter Lightspeed spark create more explosive
force than two mags firing at 25 degrees? Is this the root of the cruising
performance gain?
>From Lycoming, setting the mags at 25 degrees, I would assume this is
optimum. (Stuff Cut)
Thanks,
Bill DeRouchey
_billderou@yahoo.com_ (mailto:billderou@yahoo.com)
flying
do not archive
Message 10
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| Subject: | Dual Lightspeed? |
So since I'm the guy that started this and I've been reading everything
I can about it all, I'll chime in a bit...but I'll qualify my input
thusly - I've never built an aircraft before this one, and I've never
owned one either. I've also never worked on an aircraft engine in my
life. All of my info comes from my previous life of building drag
racing engines of various flavors for fun. and sometimes blowing them
up.
I too wondered about the effect of having 2 sparks happen at different
times - and from what I can gather, the second (25 degrees BTDC)spark
doesn't do much of anything when the first spark is firing at full
advance (around 45 degrees BTDC). When the firing of both sparks is
closer, I would suspect that (and I have no data to support this - just
a guess) the first spark initiates the combustion at a more optimal
time, and the second just contributes to the ignition of the remaining
gas charge, and depending on the speed of the flame front, may not do
much still. According to lightspeed's site, the spark is an
uninterrupted 20 degrees in duration. I don't know what the duration of
the magneto's spark is (maybe someone else does?), but I imagine that at
most RPMs and MPs, the lightspeed spark would happen at a more optimal
time, and the magneto spark would sort of "chime in" upon reaching 25
deg BTDC while the lightspeed is still firing. At least conceptually
this seems fine to me.
In theory, I suppose that you could also run much leaner without
roughness, because you can advance the timing to a point that you will
still achieve a complete burn (or more complete I should say) of the
fuel charge. Again, in theory, you could lean and lean and lean, and
advance (with manual control) and advance and advance, and get a very
low fuel burn.
To answer your question about advance, the 25 degree setting of a
magneto doesn't seem optimal. I sort of look at it as a middle of the
range value that works everywhere (at all altitudes - within reason of
course) but isn't really optimal everywhere. In a race car, you're
tuning so that everything is optimal at WOT and nowhere else. As long
as the car will idle on the starting line without choking itself out,
you're good. Of course you're pouring unburned fuel into the exhaust
pipes and the car wants to shake itself to pieces, but that's ok. I'd
basically run mechanical advance only (no vacuum advance), and have it
all in at something like 2500 rpms, if the redline was around 6500 or
7000. If I remember right, fully advanced, it'd be somewhere in the
neighborhood of 45 or 50 degrees at full advance, and somewhere around
25 to 30 degrees at idle. Advanced timing and long spark duration is
what you need if the rpms are up and the cylinder pressures are high.
Add nitrous, and everything changes (see the above note about things
blowing up). In an aircraft where the air pressure changes, the mixture
can be controlled from the cockpit, and WOT equals 2600 or 2700 rpms, 25
degrees of advance seems ok, but it seems to be a compromise that costs
the engine efficiency as rpm and mixture changes.
Again - I'M NO EXPERT. Mostly, I'd get under the hood wind the engine
up to full throttle, and turn the distributor back and forth til the
thing ran right, then look at the number with the timing light and say
"oh. I guess that's the number." I realize that a bit more finesse is
required when your life depends on the thing running right... :-)
cj
#40410
fuse
www.perfectlygoodairplane.net
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Bill
DeRouchey
Sent: Friday, October 20, 2006 10:06 AM
Subject: RE: RV10-List: Dual Lightspeed?
I have a question for those familiar with Lightspeed (etc) ignition
systems that I have been pondering for some time. Purchased a 25 SFOH
engine with new mags and saw no good reason to upgrade. One mag was
equipped with dual points "flash of sparks" and added a SlickStart in
place of the old Bendix vibrator. It starts easily.
If you configure a system with Lightspeed and a Slick mag I would assume
that the Lightspeed is firing at 25 degrees advanced up to 45 degrees
while the Slick mag is always firing at 25 degrees. So what is happening
to the force of the gas explosion?
I cannot imagine that the Slick is contributing to the ignition if the
Lightspeed is advanced beyond 25 degrees. Therefore, does the single,
hotter Lightspeed spark create more explosive force than two mags firing
at 25 degrees? Is this the root of the cruising performance gain?
>From Lycoming, setting the mags at 25 degrees, I would assume this is
optimum. What is gained when advanced beyond this point? How would the
cockpit controlled variable timing be used strategically? Do we have
firm evidence that a Lightspeed/mag configuration produces more
horsepower than two mags?
I understand the ease of starting argument but need more facts to
understand the claim of higher cruise performance.
Thanks,
Bill DeRouchey
billderou@yahoo.com
flying
do not archive
"Stewart, Michael (ISS Atlanta)" <mstewart@iss.net> wrote:
--> RV10-List message posted by: "Stewart, Michael (ISS
Atlanta)"
I had dual hall effects in my 6.
Have Direct crank in my 8.
Mike
Do not archive.
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Tim
Olson
Sent: Thursday, October 19, 2006 3:39 PM
To: rv10-list@matronics.com
Subject: Re: RV10-List: Dual Lightspeed?
--> RV10-List message posted by: Tim Olson
I see Mike Stewart also replied that he sees no problems.
One thing to be aware of is that Mike probably has the
rear mounted hall effect sensors (or am I wrong, Mike?),
so it isn't the same as the IO-540 crank sensor mount.
Bob's got a good idea of separate routing. I was also
*slightly* personally worried about the fragility of
the electronics up under that hub...and about the
what-if's during bad weather, or even lightning/static
discharge. Again, I'm not saying "don't do it"...just
giving my rationalization. I'm just as swayed to go
dual electronic some
Message 11
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|
--> RV10-List message posted by: "Billy" <billykay1@aol.com>
Hello again,
I am the guy who started this subject about a week ago. Thank you all for participating.
I am still undecided at this point about the engine but your comments
have been helpful.
I trained as an A&P in the early 80s, worked for the airlines a while as a mechanic
(which does little for you O540 knowledge or generally sheet metal as well).
I currently fly for a small cargo airline using the 747-400s, which gets a
bit boring on 14 hour flights.
I did overhaul a cont. O300 and a lyc O235 back when I was learning to fly. They
seemed to run pretty much the same before and after overhaul.....Have previously
owned two older 172s one with the O300 and one with the O320. I cant remember
the O300 being that much smoother (could very well just be my memory) Also
a 150 a 152 a 210A and a 1976 182
Would like to connect with other 10 builders in the chicago area. I have a tail
kit and am pretty much done with section 9 and hope to start on section 10
before the end of the year.
One of the posted that struck a cord with me was from Scott Schmidt:
"Here is the truth with all of this, none of it really matters a lot.
They all seem like big decisions when you are planning and building but
when you are flying all you really care about is that the engine runs
great, you have good communication, and the weather is good. I spent
days and days (maybe months or a year) planning my panel, paint, wiring
and interior. When you take off it is nice to have some of the features
but really you are looking outside and having a great time."
Thanks Scott.
But thanks to all that have posted.
Billy Kehmeier
kit #574
starting on tail cone
Chicago
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=69165#69165
Message 12
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| Subject: | Re: Mags vs electronic ignition |
Chris,
Interesting! Taking a little different tack, will your panel be
all electric? I still think a vacuum backup is a good idea when the
smoke starts to escape from the boxes. As you say, there's no time to
troubleshoot when you can't see or breath. No mattter how much
electrical redundancy you have, your only choice is to shut it all down
when you suspect fire of electrical origin. This may be heresy to this
group. Luckily, you weren't in the air.
Message 13
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--> RV10-List message posted by: "Phillips, Jack" <Jack.Phillips@cardinal.com>
Here is the other engine off the Aztec that I bought my engine from:
http://cgi.ebay.com/ebaymotors/Lycoming-0-540-A1D5_W0QQitemZ110045101117
QQihZ001QQcategoryZ26439QQrdZ1QQcmdZViewItem
Good price for a core, even better price for a running engine. I
received my engine from this guy last week and it is exactly as he
described and appears to be in good shape. Mine had less time than this
one - you might want to just use this one as a core.
Jack Phillips
_________________________________________________
Message 14
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| Subject: | Dual Lightspeed? |
Flame front propagation is a fascinating topic. F/A mixture is hotter
near the exhaust valve that a comparatively cooler intake valve. Heat is
a catalyst for combustion. If it is a charged carbon deposit and
ignites a mixture at other than the required timing it gets its own name
- Detonation. If the event happens before the piston is ready to
provide the power-stroke and it is before the exalted event, it is
called PRE - ignition. Read the GAMI site. The theory is they both
meet in the middle in perfect harmony. Distributor, Mag timing and
Electronic timing and all things spark related need to change with the
change of engine load and rpm. A finite setting does not enhance this
phenomena.
The phrase Optimum is a mis-leader in that it is the better of a poor
trade off. PRISM will address this need for a changing advanced spark
curve. One of the vulnerabilities of Mags is they are Primeval - Brain
Dead simple and reliable at a single setting throughout a range of
performance requirements.
Everyone building should make their personal decision based on research
rather than popularity of the moment.
John Cox
________________________________
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Bill
DeRouchey
Sent: Friday, October 20, 2006 10:06 AM
Subject: RE: RV10-List: Dual Lightspeed?
I have a question for those familiar with Lightspeed (etc) ignition
systems that I have been pondering for some time. Purchased a 25 SFOH
engine with new mags and saw no good reason to upgrade. One mag was
equipped with dual points "flash of sparks" and added a SlickStart in
place of the old Bendix vibrator. It starts easily.
If you configure a system with Lightspeed and a Slick mag I would assume
that the Lightspeed is firing at 25 degrees advanced up to 45 degrees
while the Slick mag is always firing at 25 degrees. So what is happening
to the force of the gas explosion?
I cannot imagine that the Slick is contributing to the ignition if the
Lightspeed is advanced beyond 25 degrees. Therefore, does the single,
hotter Lightspeed spark create more explosive force than two mags firing
at 25 degrees? Is this the root of the cruising performance gain?
>From Lycoming, setting the mags at 25 degrees, I would assume this is
optimum. What is gained when advanced beyond this point? How would the
cockpit controlled variable timing be used strategically? Do we have
firm evidence that a Lightspeed/mag configuration produces more
horsepower than two mags?
I understand the ease of starting argument but need more facts to
understand the claim of higher cruise performance.
Thanks,
Bill DeRouchey
billderou@yahoo.com
flying
do not archive
"Stewart, Michael (ISS Atlanta)" <mstewart@iss.net> wrote:
--> RV10-List message posted by: "Stewart, Michael (ISS
Atlanta)"
I had dual hall effects in my 6.
Have Direct crank in my 8.
Mike
Do not archive.
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com] On Behalf Of Tim
Olson
Sent: Thursday, October 19, 2006 3:39 PM
To: rv10-list@matronics.com
Subject: Re: RV10-List: Dual Lightspeed?
--> RV10-List message posted by: Tim Olson
I see Mike Stewart also replied that he sees no problems.
One thing to be aware of is that Mike probably has the
rear mounted hall effect sensors (or am I wrong, Mike?),
so it isn't the same as the IO-540 crank sensor mount.
Bob's got a good idea of separate routing. I was also
*slightly* personally worried about the fragility of
the electronics up under that hub...and about the
what-if's during bad weather, or even lightning/static
discharge. Again, I'm not saying "don't do it"...just
giving my rationalization. I'm just as swayed to go
dual electronic some
Message 15
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|
--> RV10-List message posted by: <millstees@ameritech.net>
Billy:
I am building a -10 in Naperville. I am using an Eggenfellner Subaru H-6
engine. Give me a call (630) 308-7476 cell
Steve Mills
RV-10 40486 Slow-build
Naperville, Illinois
finishing fuselage
-----Original Message-----
From: owner-rv10-list-server@matronics.com
[mailto:owner-rv10-list-server@matronics.com]On Behalf Of Billy
Sent: Friday, October 20, 2006 2:32 PM
Subject: RV10-List: Re: engines
--> RV10-List message posted by: "Billy" <billykay1@aol.com>
Hello again,
I am the guy who started this subject about a week ago. Thank you all for
participating. I am still undecided at this point about the engine but your
comments have been helpful.
I trained as an A&P in the early 80s, worked for the airlines a while as a
mechanic (which does little for you O540 knowledge or generally sheet metal
as well). I currently fly for a small cargo airline using the 747-400s,
which gets a bit boring on 14 hour flights.
I did overhaul a cont. O300 and a lyc O235 back when I was learning to fly.
They seemed to run pretty much the same before and after overhaul.....Have
previously owned two older 172s one with the O300 and one with the O320. I
cant remember the O300 being that much smoother (could very well just be my
memory) Also a 150 a 152 a 210A and a 1976 182
Would like to connect with other 10 builders in the chicago area. I have a
tail kit and am pretty much done with section 9 and hope to start on section
10 before the end of the year.
One of the posted that struck a cord with me was from Scott Schmidt:
"Here is the truth with all of this, none of it really matters a lot.
They all seem like big decisions when you are planning and building but
when you are flying all you really care about is that the engine runs
great, you have good communication, and the weather is good. I spent
days and days (maybe months or a year) planning my panel, paint, wiring
and interior. When you take off it is nice to have some of the features
but really you are looking outside and having a great time."
Thanks Scott.
But thanks to all that have posted.
Billy Kehmeier
kit #574
starting on tail cone
Chicago
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=69165#69165
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