Ignition modules

[mr bill]

Lowell:
Can you post pictures of your engine and oil tank mounting? Did you have to change the cowl?
Bill

[HighWing]

The short answer is yes, but it amounted to adding a couple of inches to the aft edges of the bump cowls.

Two pictures. The first is what prompted the modification of the firewall forward. I added ribs and gap seals to both horizontal and vertical surfaces and some fairings. It added about six or seven pounds back there. At 11 ft. aft of the datum it added about 65 foot-pounds aft. I did the same on the first IV and for weight and balance purposes, I was limited to 25 lbs. in baggage. To eliminate that restriction on the new IV, I moved the engine forward a couple of inches which provided room for the oil tank in a better location. And rather than putting a bubble on the cowl to accommodate the lower edge of the tank, I did some body work on it by hammering it to clear and then some micro and paint. The ignition module mount is a welded bracket attached to the aft section of the engine mount.

[mr bill]

Lowell:
Really well done! Too late for me now though. In July it will be 5 years on this project and all painting is done. I'll think some more on this.
Bill

[glasseye]

I'm wondering if I have a similar issue, 912 UL when running at 4200rpm on LH ignition unit it misses badly. Increase RPM slightly and it runs smooth. Decrease slightly from 4200 and also smooth.