Being a big horsepower, small tail, LNC2 pilot, I'll offer my opinion.
From an alignment perspective, check your nose gear fork and how it attaches to the strut. Not sure if the 235 kit is like the 320/360, but if it is, the attachment holes on the strut are actually slots. This allows for a certain amount of play left or right to align your fork. Once aligned, the clamp on top maintains the position. Keep in mind, if your strut is self centering when extended, the only way to really see where it wants to point is with the strut fully extended. So, to check it, make sure the
strut is fully extended, line the airplane up on a taxi line, and pull it from the prop for a bit. See if it tracks on the line. Mine was a bit off actually and a small adjustment on the fork made taxing much more relaxing.
But.. I doubt that is your problem.
For new(er) pilots to this airframe, it takes some time to isolate the rudder movement from the brake application. It is very easy to add a foot full of rudder and apply a bit of brakes also.. One thing I advise is to not wear stiff boots and allow yourself a bit more dexterity in your feet. It makes it easier to feel the brakes and the very little travel they actually have.
Now, be aware of this: If attempting to raise the nose during a fast taxi in a small tail Lancair, it is very likely the airplane will take off. Part of the 'issue' I see is the wing is
flying before the tail is probably effective enough to rotate the nose. With my airplane, the rotation and liftoff happens pretty much all at once. As soon as the nose lifts, so does the airplane. So if you intend to raise the nose, I would prepare to do your first landing as well. Your runway may be a bit short for all of this to happen comfortably. The more I think about this, I suppose if you did not have takeoff flaps, it might be possible to carry the nose. But man, that is a fine margin in my opinion.
For me, I can slowly dial in takeoff power (well over 200hp)
without any major directional issues. I start with full right rudder, add power, use a touch of right brake as needed to keep it on centerline. Generally by the time I am rotating I am easing off some rudder as it is getting more and more effective. Applying left rudder is a rare event, unless wind is a factor. I have a stock rudder with no dorsal fin.
Tom McNerney
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This morning I made several fast-taxi runs in my Lanciar 235/O-290-D2. The first few runs were with empty wing tanks and it got real squirrely. The plane would veer from side-to-side with a period of about 3 seconds and it was all I could do to keep it on the runway. I got scared at about 50 KTs, pulled the power, and applied the brakes heavily to keep from going into the weeds. I never could get going fast enough to lift the nose wheel.
I taxied back to the hangar and added 5 gallons of 100LL in each wing tank and repeated the test. The results were much better but the side-to-side oscillation was still there and it was easy to get into a P.I.O.
Is this normal behavior for the small Lancairs? Could this be due to something in the oleo strut? (I don't have the centering mod)...Tire pressure?...Dragging MLG brake?...Any other ideas?
FWIW, I added a 5" ventral fin and extended the rudder 5" to avoid just this sort of thing with the larger engine. Apparently, those mods don't work at low speeds.
Help!