cowling fit

[plumbflyer]

I am having fit problems with the van's cowling to the prop hub. I have an ECI titon IO-360 with a Whirlwind 200rv prop. The top cowling when centered properly has a 5/32" gap on the pilot side and a 8/32" gap on the co-pilot side. Wondering if anyone has had this problem and what they did with it.
Plumbflyer

 

[BigglesRV7A]

Cowling fwd fit

I am assuming you mean the gap either side of the WW200RV spinner? If so this is pretty normal with first fitment. After allowing for desired engine sag (I allowed 1/8") on the top cowl I then cut a circle from thin plastic the same size as the rear of the WW spinner. I used this to make sure when both cowls were trimmed together at the front they made a perfect circle. Once this had all been completed, with cowls together you can set about aligning the gap to be even all around between the front of the cowl and the rear of the WW200RV spinner. I had the prop and spinner on to measure this initially. I then removed the Prop/spinner, and using a larger than rear spinner dimension (~20"x20") piece of 1/2" MDF board I covered with packing tape. I then Made a mixture of Micro Balloon/Flox, placing this to equalise the gap as previously measured. I then Squeezed the board to the front of the cowls and secured until Mico Balloon set. Removed board, sanded back accordingly with piece of 2"x4" board with long piece (25") sandpaper attached. I then placed 3-4 pieces of fine Fibre glass cloth over the filled areas for additional support. This was a painstaking process though well worth the effort in terms of result.

Hope this all makes sense,

Greg

 

[plumbflyer]

prop gap

Greg, thanks that does make sense. It looks like you have to set the closest side to the proper gap and then fill the rest to match. The top to bottom gap is good; same as left side, it just opens up at the right and doesn't look good to me.
Phil

 

[BigglesRV7A]

Got it!

Youv'e got the idea right. To separate the two cowl section (top/bottom) I used a small fine file to score the appropriate line and then lightly tapped the area until it cracked along this line. Doing this all together will give you a perfect gap all round the rear of your spinner which looks like it is nearly there already given your initial dimentions. If you look at the engine inside the bottom cowl it is offset to account for torque/Pfactor hence the cowl gaps are slightly different. I wondered about this at the time given all the cowls should account for this though was assured everything was in order and to proceed as described above.

Happy building,

Greg (RV-7A, IOF-360, WW200RV, Final 99%, AUSTRALIA)