Model 6 FWF Evolution

[Av8r3400]

Not wanting to hijack the January 2016 KFOTM, I'm starting a new discussion.

Patrick Hintz' Model 6 has a unique FWF and cowling setup.

A question to those in the know: Is the Model 6 a different FWF from the model IV and to that point where does the Model 5 fit into the evolution?

The smooth cowl IV FWF seems to be an after thought, with it's oil tank placement (scalloped/frenched into the firewall) and very short profile. It appears shorter than the 6 shown in the KFOTM feature. Maybe a way of getting a new look without completely redesigning the round cowl engine mount?

The model 7 (SS), with it's boot cowl and extended cowl looking much sleeker and faster, seems to have take this evolution to it's final profile.

Thoughts, comments, discussion?


Model 4 (Kitfox Gallery - DesertFox4's IV?)


Model 6 (Patrick Hintz' beauty)


Model 7SS (Kitfox Gallery)

[Pilot4Life]

What I see is evolution from the old "radial" look of the 1-4, to an O-200 look bringing the KF into a more modern GA look, then onto the newest cowling setup that somewhat replicates a Cessna Corvalis TTx. Thus being sleek and more aerodynamic, giving an increase in speed from the great redux in drag. I like all 3 styles respective to era and vintage. Just my two cents!

[jmodguy]

From what I have been able to determine the V was the re-design that the 6 and 7 were derived from. It is nothing like the IV and few if any parts are interchangeable between the 4 and V, 6, and 7 models.
Parts for the 6 and 7 can be retrofitted on the V including firewall forward kits, flaperon hinge upgrades etc. I would assume some V parts are interchangeable with the 6 and 7.
Some V models have 1400GW wing spars and the later ones have the 1550 spars. This happened somewhere mid 1995 from what I can tell.
Somewhere in there (5,6,7 development) Kitfox changed the Rotax 912 engine mount from the dynafocal to the ring mount. With the dynafocal I think the intakes have to be swapped left to right. With the newer ring mount they do not. This might be where the cowl change came in but I do not know for sure.

Regards,
Jeff

[HighWing]

I think Jeff pretty much got it all down. The V was at one time intentioned to be submitted for certification. The factory welding fixtures were very robust for that reason. It is my understanding that the 6 and 7 fuselage is produced from the original V tooling. Heavier weights in the empennage required a forward positioning of the engine.

A thought on your project. Have you determined how much weight the empennage mods added to the tail of the project. the reason I ask is that I did some and likely a little more and the addition was calculated to be just under 7 lbs. At an 11 foot arm it seriously impacted W/B. On my first IV, I did some of the same mods and the W/B calculation resulted in a placard on the baggage area limiting contents to 25lbs vs. the 40 in the design. to take care of that, I moved the engine 2-1/5" forward (About an inch too much I subsequently found), but the redesigned engine mount provided a lower location for the oil tank. I used the same cowl adding a couple inches to the aft edge of the main cowl and some more to the aft edge of the round cowl. You could do the same with the factory IV smooth cowl and perhaps a redesign of the top giving an approximation of the sleeker profile of the 7. Definitely a bit of work, though. The oil tank picture reminds me that I had to modify the tank a bit. I did that with a hammer and a bit of Featherfill (The reason for the paint). I have a quarter inch clearance now.