R

Ron B.

Well Known Member
I have a new Lycoming IO-390 and I am exchanging the right magneto with a Lightspeed Plasma III. The Lightspeed manual recommends using the top side of the cylinders for the Plasma plugs and the bottom side for the Slick magneto. The right mag. fires up the bottom plugs on the right side and the top plugs on the left side as is. I doubt ,but will verify that the magneto will have issue with firing the bottom plugs but my leads are too short if I move from the top location to the bottom.
My Plasma leads are also to short to reach to the bottom position on the left side also. If the right mag. can indeed fire the bottom plugs can I exchange the two left leads with some of the correct length from the left mag. I removed?
Any help on this topic would greatly be appreciated as always.
Thanks Ron
 
I just did this on my Rocket when I added the CPI ignition and there was plenty of length to move from the upper plugs to the lower on the remaining magneto.
 
The leads will reach but I will not have enough to secure them properly. Any chance you have a photo of your install on the left side?
Thanks Ron
 
I don't have any pictures and the cowl is on at the moment, but if yours "reach", I'm not following how they can't be secured. Are they just "barely" making it to the plugs? Do YOU have a picture?
 
Short

I have a similar problem. I moved the slick harness to the bottom plugs on one side, and the wires are "tight". Existing attach points for bottom plug wires is using the bottom bolt/screw in valve cover. Needs just another inch and everything would be normal. Since I pulled the left slick and installed EI, I guess one could use two of the longer wires but I'm thinking they will be too long. I'm thinking about moving those massive plugs back to top on one side and stagger the EI plugs. Not too crazy about running automotive wires on the bottom plugs but short of buying two longer wires, not too many options. I'm all ears here too.
Cj
 
Same situation Grubbat describes and yes I do have a photo but have not been able to post. If you can provide me with an e-mail address (PM it to if you like) I'll send it to you.
Ron
 
Ron B. said:
I have a new Lycoming IO-390 and I am exchanging the right magneto with a Lightspeed Plasma III. The Lightspeed manual recommends using the top side of the cylinders for the Plasma plugs and the bottom side for the Slick magneto. The right mag. fires up the bottom plugs on the right side and the top plugs on the left side as is. I doubt ,but will verify that the magneto will have issue with firing the bottom plugs but my leads are too short if I move from the top location to the bottom.
My Plasma leads are also to short to reach to the bottom position on the left side also. If the right mag. can indeed fire the bottom plugs can I exchange the two left leads with some of the correct length from the left mag. I removed?
Any help on this topic would greatly be appreciated as always.
Thanks Ron
Click to expand...

I see no reason why you can't use any length magneto lead you find necessary.

That said, anyone know the reason behind the recommendation to keep the magneto-fired massive plugs on the bottom?
 
Can You explain how the end , and which end of the lead I remove in order to do the exchange?
Thanks Ron

DanH said:
I see no reason why you can't use any length magneto lead you find necessary.

That said, anyone know the reason behind the recommendation to keep the magneto-fired massive plugs on the bottom?
Click to expand...
 
Magneto leads on the bottom

Dan, to answer your question, it varies by provider. Klaus recommends the lightspeed plugs be on the top due to something like flame propagation nearer the injectors. In speaking with Electroair they recommend their system to be installed with the magneto plugs on top and their plugs on the bottom. Supposedly the hotter spark from the EI helps prevent lead fouling.

Having had a number of lightspeed systems on my airplanes, I am about ready to try the Elector air and see if it makes a difference with the fouling.

Vic
 
Bottom massive

One of the reasons I was thinking about using massive plugs on bottom was that the wires seem more secure with the plugs pointing down. I guess it just seems less likely that they will come off compared to automotive wires. However, I don't have any evidence that is a real risk. I ran automotive plug wires several years ago on another project and never had any issues..... just trying to minimizing risk on this build. Automotive on top just seems logical. Anybody have any info that auto wires on bottom is not good?
Cj
 
I'm running dual light speeds so I have auto plugs top and bottom never had any oroblem on the bottom. The terminal that klaus uses has a positive click when it seats, you can hear and feel it

Bob burns
RV 4 n82rb
 
All leads from the EI should go to either top or bottom plugs, not half top, half bottom as typical mag set-up. All cylinders therefore have the same flame-front and performance. Mags criss-cross to avoid different rpm drops when checking L and R because the burn is different between just bottom and just top with the weak mag spark.

With a single EI, I'd wire it to the bottom plugs. But I wouldn't have two types of ignitions, either, and that's a whole 'nuther thread in the never-ending debate column.

John Siebold
 
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