LSE coil placement

Gonzo24 · #1 03-23-2012, 09:02 AM

currently planning my coil placement for dual lightspeeds and was curious what the field recommendation is for these options:

-on top of engine case.
-on engine mount with adel clamps
-on firewall.

the LSE manual states all are ok. I have FI with the AFP purge so its a little crowded on top with 4 coils. any cooling issues on the mount or FW. seems as though engine case would be better cooling for an apparent weak link in the system given previous posts. would think that auto installs would be similar in heat under the hood during summer driving.

Pmags, EFII and Eagle coils are aft of the baffles as well. ah the choices.

thanks,

gereed75 · #2 03-23-2012, 09:12 AM

I originally mounted my single set of LSE coils under my plenum (above engine "inside" baffles) as shown in the LSE literature.

I had a coil breakdown after about 100 hours. I think it was heat related.

I moved the mounting to the engine mount cross tube immediately behind the baffles. This required a fabbed bracket and some slightly longer spark plug leads (made up for me by Klaus) but made attachment of hign tension leads easier (I used 90 degree Spay terminals).

I like this much better. I'm sure it is cooler (no coil problem since moving) and I can reach in and check the security of the high tension connections via the oil filler door during pre-flight.

I recommend this spot, worked well for me. Might be a bit cramped with two sets of coils though. Good luck

DocThrock · #3 03-23-2012, 09:18 AM

I have fuel injection with the AP purge valve on my TMX-IO-540. Mattituck put my dual coils on nifty little brackets along the top spine of the engine. Yeah, they are shoehorned in between the injector lines in some places, but they fit up there nicely. Slightly elevated and up in the breeze. No plenum. Sorry, I don't have a very good picture of the setup. And I don't know where Mattituck got the brackets.... 180+ hours and still going strong.

Gonzo24 · #4 03-23-2012, 12:43 PM

Gary, Doc: thanks for taking the time to respond. I like the idea of checking the leads on the mount during preflight. I think I will give that a shot first go round.

Gary - if you get a sec, I would really like to see your mount. PM if you want.

thanks,

Lars · #5 03-23-2012, 01:52 PM

I wanted mine above the engine, so in flight the coils are cooled by incoming air rather than air that's already passed across the cylinders. There weren't too many options due to the fuel injection hardware. I wound up with them just ahead of the back baffle wall, on a composite bracket I made from pieces of 4130 and aluminum.

gereed75 · #6 03-23-2012, 02:15 PM

Quote:

Originally Posted by Gonzo24

Gary, Doc: thanks for taking the time to respond. I like the idea of checking the leads on the mount during preflight. I think I will give that a shot first go round.

Gary - if you get a sec, I would really like to see your mount. PM if you want.

thanks,

Trying to find some pictures, check your PM's. Gary

jay.pearlman · #7 03-23-2012, 07:01 PM

The placement depends if you have a plenum over the engine. If you do, the coils will stay/become hot after shutdown because the plenum will contain the heat. Klaus suggested not on top of the engine if there is a plenum. I put the single coil on the firewall (one mag and one LSE on my engine) and Klaus provided the new cables.

molson309 · #8 03-24-2012, 05:33 PM

How is a plenum any different than the top of the cowling in this regard? Both will trap heat after shutdown. In both cases incoming air, during operation, will tend to cool the coils and dissipate any heat build up due to energy released by the operation of the coils. Since there is no internal heat being generated after shutdown, I maintain that heat soak at that point is less damaging than running the coils in a hot location when the engine is running.

This being said, my RV-7A engine has a plenum and two LSE coils mounted on top of the engine. After 7 years, it has about 700 hours on it now and the coils are still going strong.