cowling

[fuzzypilot]

I purchased a used bump cowl from a another Kitfox. Some of the holes in the cowl don't match my mounting tabs on the fuselage, but I half expected that. My question is when I mounted on the airplane the left side of the cowl is 1/2 inch longer on left side than the right. Is this to compensate for right thrust built into the mount or was it trimmed wrong? If I move the whole cowling assembly on the left aft 1/2 inch, it actually fits better. I don't want to cut this if it supposed to be offset to the right. Anyone have any insight?

[Delta Whisky]

Fuzzy - it might be a function of the engine choice. What are you using? My round cowl mounting instructions (SS7 with ULS) specified centering the cowl on the prop flange. HTH. Darrel

[fuzzypilot]

I plan on using a Rotax 582, because a 912 just isn't in the budget. I think the airplane this cowl was on used a 912. The mount appears to have right thrust built in.

[efwd]

Remember that these parts are all custom to each airframe. My cowl will certainly not fit anyone elses aircraft without modification.

[HighWing]

I plan on using a Rotax 582, because a 912 just isn't in the budget. I think the airplane this cowl was on used a 912. The mount appears to have right thrust built in.

I built my own engine mount for a 912UL and did some research that indicated that there is no thrust offset in the Model IV. My take on the variations of the positioning and the attachment point locations is due to the minor discrepancies in the assembly and welding process at the factory and also during the building process. Example: If the round cowl is installed with the spinner exactly in the center of the cowl opening, There will be a definite loss of forward view in three point and locating the oil cooler will be more of a challenge. Most builders compensate a bit for these and other reasons so no installation is exactly the same.

[fuzzypilot]

I realize the variation in tab locations, and I anticipated that when I bought this. My real question is the horizontal length of the rear upper and lower cowl sections measured at the joint. Measuring from the front door post to the front edge of the cowl, there is a 1/2 inch difference in length.

[HighWing]

I went out and measured mine and the lengths at the upper and lower joint is exactly the same. Then got and idea. On my IV, the front edge of the door opening is quite angled and dropping the tape measure about a half inch lengthened the measurement almost a half inch. My guess is that if the joints are not exactly level right to left, a quarter inch discrepancy - each side - might result in what you have. Then - I just measured the vertical distance at the door - I have a quarter inch variation top to bottom one side vs the other. Another note, when the kit arrives, the cowl parts are right off the mold - all over-sized. the final trim in all dimensions is to provide the proper alignment of the cowl to the prop/spinner location.

[fuzzypilot]

Highwing, thanks for your input. I guess I need to make some more measurements and fill some holes.