kifox IV 1050 with hirth 3703

[jwlt500]

I'm in the process of rebuilding a IV with a 582 that went on it's back and installing a 100 hp 3703. Would it be worth it to install larger tail feathers and go with larger wing struts with a solid tube between strut attach points? Any thoughts on the 3703?

[Dave F]

If you got to make a new tail - sure make it taller like the 1200
the other mods - not sure about them.
I have never heard of a IV 1050 break apart there yet or have a wing strut failure. I have seen 1050 flying at 1400 to 1500 lbs but never at high G's

The Hirth - no experience.
-used to be a saying that there are 2 kinds of Hirth engines.
The ones that blew up and the ones that just have not yet.

Rotax best bang for weight - 582- 912 ul or 912 S\

[HighWing]

...go with larger wing struts with a solid tube between strut attach points?

I have been told and again this is anecdotal, that the tube that spans the lift struts at the wing attachment end were placed there for ease of assembly - essentially giving a dimension betweent the struts when rigging the lift strut attach brackets and getting everything rigged to design specs. There was talk of removing them after rigging for weight saving. This info from a nearby friend who built a 604 lb. Model IV with 912. It was a spritely beast that flew tons of hours and one incident witnessed by me and others when he inadvertently flew through a dustless dust devil. No damage to the airplane, but some serious anxiety to all involved.
Lowell