Ignition Shielding

[Guest]

Scott,

I attached some pictures.

BG 4B2s is about 5/16" shorter including the elbow.

The plug next to it is BG 919SR-5. 4B2s plugs use a smaller elbow.

I have a NOS set of plugs and elbows on the shelf. Elbows are very easy to swap out on the harness end.

There are some plugs on ebay => https://www.ebay.com/sch/i.html?_fro...+4b2s&_sacat=0

I got mine from Lou Liebee. Fresno Air parts should have plugs and elbows.

Dave R










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[M Towsley]

My cowl fit so tight I had to utilize four Ercoupe cups to accomplish having no cowl bumps. My first BC-12D had very small homemade metal bumps that hardly showed. Each cowl seems to be a bit different but some of the commercial bumps look like you have a radar dish under them they are so large.

Though not my pictures this was my first '46 BC-12D I owned about 14 years ago.

[Scott]

Thanks Marty and Dave.
I'm going to the hangar tomorrow so I'll take some measurements (assuming I can did through the foot+ of snow we just received)

I also found these; https://www.aircraftspruce.com/catal...testplugs8.php Which are supposed to be 1/2" shorter.

The smallest clearance is on the left side. The cylinders are about an inch further forward on the left which puts the plug under the flange of the nose bowl. I have about 1/4" clearance above the M41E.

[Scott]

SO I have just over 2.5" from the spark plug insert to the nose bowl flange. Appears the cup option is the only one that might work. Anyone have a dimension for the cup?

[woodmw]

Fresno Airparts lists them as 2 5/8"

[Scott]

Well that makes things tight!
hmmm