emag/pmag

[tshort]

Anyone ordering before the price increase?
I haven't thought in depth about the ignition system yet, but a 200$ price increase is pretty significant .... ?

Thomas

[cjensen]

I had a great piece of advice given to me this past weekend...

I am planning Emag/Pmag also, but here's an idea to save some dough, and get the most bang for your buck at the same time. All new engines are priced and sold with mags (usually Slicks). Keep those because they won't credit your order what they are worth. Buy one Emag or Pmag for now. Use one mag with the E or Pmag until the mag needs replacing or major $$ work is required of it. Toss it aside, put the other mag on in it's place (make sure you've preserved it while it's on the shelf for the years it will take to do this). Run it until it quits or needs work. THEN buy the other E or Pmag.

This way, the whole time you are running electronic ignition, and you get your money's worth. It's an idea I'm SERIOUSLY considering. 'Course you do need 4 expensive aircraft spark plugs for the mag bank...

[captain_john]

I am not sure about the pricing thing and I am really not that good at math, but buying 3 mags and keeping one on the shelf certainly costs MORE than buying 2.

Me? I am likely to go Dual P-Mags, but I may substitute one for an E?

Here's the deal that I heard...

Granted, THIS IS RUMOR... but sounds logical. I will verify it later.

The P-Mag's spark when it is operating under it's own permanent magnet is somewhat weak. As a result, you need to gap your plugs smaller. This is so that if you do lose ship power, you will be assured of a good spark to continue flight.

This is reason to substitute one for an E and gap it larger so that at least you will be getting ONE good, hot spark during normal operations.

Now, as far as combining an electronic ignition and a traditional mag... doing this would cancel out any benfit of having an electronic ignition in the first place.

Reason being, the Electronic Ignition has a very precise, ADVANCE-ABLE spark. It fires AFTER top dead center.

The Mag has a longer duration and is less precise.

If you combine the two, you negate any benefit of the precise EI spark.

NOW... I COULD be ALL WET on this one. Buuuut, I think I am pretty close to the mark.

Anyone???

CJ

[Spike]

The advanced timing moves the spark forward in relation to TDC. This is so you get the high compustion pressures earlier in the down stroke. It takes the charge x amount of time to burn. The faster the engine is spinning, the farther down on the power stroke it has gone before peak combustion pressure has occured. Thats a loss of power. Advancing the spark allows the charge to burn to its max energy output befor the piston is farther down its stroke.

[cjensen]

I am not sure about the pricing thing and I am really not that good at math, but buying 3 mags and keeping one on the shelf certainly costs MORE than buying 2. <snip>

Well, for some reason, it made sense when Bob Nuckolls said it. I may have missed a detail in there, but I think what he was saying is that the engine company's do not give you anywhere near the amount of credit as the mags are worth if you elect to ommit them. Since the engines are already priced WITH the mags, all you do is add one E or Pmag. If you ommit both mags (and take the little amount of credit), and add two E or Pmags, it costs more. I'm too tired to look up the numbers right now, so if I'm wrong, I'm wrong. Ill check later.

I DO agree about using one of each negating the electronic advantage.

As far as spark plugs go, I was under the impression that automotive plugs where used with E and Pmags.

[captain_john]

They are using auto plugs.

I am still unsure about that, but statistically it seems to be working fine!

I am willing to take a reasonable credit for the mags. I am sure that with competition between vendors, the trade will be equitable.

Right now, if I were to order and engine... it would definately have P-Mags.

CJ

[jim_geo]

I've heard that E&P mags are dead simple to install.

[captain_john]

Yah, you insall them, orient them into the desired (aesthetically pleasing) position and activate a switch and BOOM! They are timed!

CJ