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Drew Dalgleish
February 23rd 06, 04:27 PM
Just read the kitplanes article on electronic ignitions. Is anyone
here flying with an e-mag p-mag combo that would like to share their
experience. Does it really make more power and any service or
instalation problems. Thanks Drew

Peter Dohm
February 24th 06, 02:07 AM
"Drew Dalgleish" > wrote in message
...
> Just read the kitplanes article on electronic ignitions. Is anyone
> here flying with an e-mag p-mag combo that would like to share their
> experience. Does it really make more power and any service or
> instalation problems. Thanks Drew

Well, I probably shouldn't be the one to try an answer, since my experience
is limited to a quick look at the EMagAir web site a few minutes ago. But
since no one else has come forward, I'll try from a purely theoretical
perspective and a little knowledge of cars long ago...

At full power, there should be no change; because the timing should be the
same as on your old magnetos. And my presumption is that the purpose is a
system upgrade, rather than to repair a deficiency in the current ignition.

Assuming that you connect the MAP sensing, there will be a spark advance as
you reduce manifold pressure and, therefore, the engine should produce
slightly more torque for a given combination of RPM and reduced manifold
pressure.

Therefore, with a constant speed prop--where you manually adjust RPM and
manifold pressure according to a table and then lean by EGT--you should
receive a slightly faster cruise and possibly slightly lower fuel
consumption.

In the case of a fixed pitch propeller--where manifold pressure is rarely
even monitored and cruise power is set entirely by RPM--the improvement
should be entirely the result of reduced fuel consumption. In some
installations, you may be able to achieve a higher RPM at some altitudes
without exceeding the maximum--yielding a result similar to that expected
for a CS prop.

I have no opinion as to whether any resulting higher power output is harder
on the engine, about the same, or even slightly easier...

I hope this helps.

Peter

Drew Dalgleish
February 24th 06, 03:56 PM
On Thu, 23 Feb 2006 21:07:36 -0500, "Peter Dohm"
> wrote:

>"Drew Dalgleish" > wrote in message
...
>> Just read the kitplanes article on electronic ignitions. Is anyone
>> here flying with an e-mag p-mag combo that would like to share their
>> experience. Does it really make more power and any service or
>> instalation problems. Thanks Drew
>
>Well, I probably shouldn't be the one to try an answer, since my experience
>is limited to a quick look at the EMagAir web site a few minutes ago. But
>since no one else has come forward, I'll try from a purely theoretical
>perspective and a little knowledge of cars long ago...
>
>At full power, there should be no change; because the timing should be the
>same as on your old magnetos. And my presumption is that the purpose is a
>system upgrade, rather than to repair a deficiency in the current ignition.
>
>Assuming that you connect the MAP sensing, there will be a spark advance as
>you reduce manifold pressure and, therefore, the engine should produce
>slightly more torque for a given combination of RPM and reduced manifold
>pressure.
>
>Therefore, with a constant speed prop--where you manually adjust RPM and
>manifold pressure according to a table and then lean by EGT--you should
>receive a slightly faster cruise and possibly slightly lower fuel
>consumption.
>
>In the case of a fixed pitch propeller--where manifold pressure is rarely
>even monitored and cruise power is set entirely by RPM--the improvement
>should be entirely the result of reduced fuel consumption. In some
>installations, you may be able to achieve a higher RPM at some altitudes
>without exceeding the maximum--yielding a result similar to that expected
>for a CS prop.
>
>I have no opinion as to whether any resulting higher power output is harder
>on the engine, about the same, or even slightly easier...
>
>I hope this helps.
>
>Peter
>
I'm considering repowering my murphy rebel upgrading from an 0-290 to
a 0-320 clone. one of the options I'm considering is an electronic
ignition instead of new slicks. The cost isn't much but I'm not sure
if it would make much difference with my low and slow plane. The prop
will be fixed pitch probably a prince composite prop to keep the
weight down.

Morgans
February 24th 06, 10:50 PM
"Drew Dalgleish" > wrote

> I'm considering repowering my murphy rebel upgrading from an 0-290 to
> a 0-320 clone. one of the options I'm considering is an electronic
> ignition instead of new slicks. The cost isn't much but I'm not sure
> if it would make much difference with my low and slow plane. The prop
> will be fixed pitch probably a prince composite prop to keep the
> weight down.

Seems to me that you would gain:
A hotter spark. Less spark plug fouling?
Easy starts, in hot and cold, with engine hot or cold.
Smoother running, from more complete combustion, at differing mixture
settings.
Almost unlimited spark plug life, longer life and reliability from the
ignition, vs the mags.
A small improvement in fuel usage.
Less concern about detonation?

I'm sure I missed some things, but that comes off the top of my head.

Me? Price being close, it would be on my new engine.
--
Jim in NC

February 25th 06, 12:07 AM
On Thu, 23 Feb 2006 16:27:04 GMT, (Drew
Dalgleish) wrote:

>Just read the kitplanes article on electronic ignitions. Is anyone
>here flying with an e-mag p-mag combo that would like to share their
>experience. Does it really make more power and any service or
>instalation problems. Thanks Drew

Today I made my first flight using an E-Mag as the left mag. On the
right side I have the Lightspeed Engineering electronic ignition. The
E-Mag is desirable due to its simplicity and ease of installation when
compared to the LS ignition. With the E-Mag there is only one part and
that is the E-Mag itself. The LS has 4 major components with lots of
wiring. The LS works very well and I have used it in conjunction with
a Bendix impulse mag for about 8 months now and have a lot of
confidence in it. The E-Mag appears to work just as well but time will
tell. E-Mag costs less than the LS ignition. I have placed an order
for the P-Mag and will replace the LS when the P-Mag is ready (a
couple of months I hope).

BTW it took 6 months to receive the E-Mag after an order was placed.

Engine is a Lycoming IO320 B1A with constant speed prop in a 21 year
old Mustang II. I overhauled the engine myself about 3 years ago and
now have 210 hours ( Hobbs meter) on it. The money I spent on the
overhaul was almost as much as purchasing a new engine.

Peter Dohm
February 25th 06, 01:15 AM
-----------snip--------------

> I'm considering repowering my murphy rebel upgrading from an 0-290 to
> a 0-320 clone. one of the options I'm considering is an electronic
> ignition instead of new slicks. The cost isn't much but I'm not sure
> if it would make much difference with my low and slow plane. The prop
> will be fixed pitch probably a prince composite prop to keep the
> weight down.

Based again on theory only; I would expect little or no change in sea level
power, but a useful improvement in cruise economy with your fixed pitch prop
application. However, the same theory also suggests more torque, with
resultant increase in RPM, when you operate with the same prop from a
hot-and-high airfield--or in the later stages of any climb to cruising
altitude.

Personally, I really like the e-mag concept--presuming that you use 2 of
them and connect the MAP sensing feature. I would be inclined to check with
E-mag Ignitions, the "clone builder" and also with Murphy. At the very
least, there is a possibility that the recommended prop pitch may
change--any prop is a compromise, and a fixed or ground adjustable prop is
more so.

BTW, while I can't give any theoretical support to an improvement in maximum
power, and I steadfastly maintain that there should not be, I admit that it
is quite possible. Electronic ignitions certainly do well on cars: they
are easy starting, give excellent spark plug life, and have shown
outstanding reliability for at least the last 20 years.

Peter

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