Bit the Bullet ... Cut hole in Cowling
Posted: Tue May 16, 2023 4:38 pm
So far the cowling and windscreen have been the 2nd most difficult portion of the build. A VERY close 2nd to the many problems posed by my split tire rims that pinched holes in my inner-tubes. It took replacement rubes from Walmart (the only place to find a tube that fit with a 980 degree filler neck) and 4 local tire shops.
The cowling and windscreen install have been giving me fits because of the configuration of the Polini 303. The electric starter motor protrudes below the gea-rcase on the port side. The beautiful bubble cowl from Chris jams against this so I (as documented) I had to find a 30mm prop extension for the Polini and modify it to fit the E-prop (Miniplane-USA, $65). This moves the cowl fwd so I'll need to add cowl cheek extensions (also documented earlier). So, I can now position the cowling fairly close to its final position, which only allows me to markup the cowling for the cout-outs for the exhaust pipe stack (lower stb side); the exhaust piping (port & stb sides); and the air-filter mounting to the carb.
I actually bit the bullet and drilled a 2.5" hole in the lower stb side for the exhaust stack ... COMMITTED! Note in the 2nd picture, on the inside (port) of the cowling I vave marked the location of the oblong cut-out that will have to be done to allow that part of the exhaust system to protrude.
With the cowling in a nice position, The windscreen work begins. Positioning the windscreen into the trailing-edge mounts (attached to the cabin/panel uprights via clecos) I noted that the channel edges and the lower curved portion of the polycarbonate (fitting into the top cowling curve) needed to be trimmed.
Note the location for the cut-out for the air-filter ... more trimming/fitting tomorrow.
The cowling and windscreen install have been giving me fits because of the configuration of the Polini 303. The electric starter motor protrudes below the gea-rcase on the port side. The beautiful bubble cowl from Chris jams against this so I (as documented) I had to find a 30mm prop extension for the Polini and modify it to fit the E-prop (Miniplane-USA, $65). This moves the cowl fwd so I'll need to add cowl cheek extensions (also documented earlier). So, I can now position the cowling fairly close to its final position, which only allows me to markup the cowling for the cout-outs for the exhaust pipe stack (lower stb side); the exhaust piping (port & stb sides); and the air-filter mounting to the carb.
I actually bit the bullet and drilled a 2.5" hole in the lower stb side for the exhaust stack ... COMMITTED! Note in the 2nd picture, on the inside (port) of the cowling I vave marked the location of the oblong cut-out that will have to be done to allow that part of the exhaust system to protrude.
With the cowling in a nice position, The windscreen work begins. Positioning the windscreen into the trailing-edge mounts (attached to the cabin/panel uprights via clecos) I noted that the channel edges and the lower curved portion of the polycarbonate (fitting into the top cowling curve) needed to be trimmed.
Note the location for the cut-out for the air-filter ... more trimming/fitting tomorrow.