Eduard 1/48 kit #8057 has instructions a bit fouled up. The one to use is C 10 but don't drill a hole in the cowling unless you are doing a LeRône powered version. The timing exhaust was different with that motor. Sopwith Camel F.1 B7270 was Capt Roy Brown's of course, RAF 209 Sqn, Bertangles, France, April 1918.
Several reviews here. "The straw that broke the camel's back"
Click here.". . .There is also a choice of two cowlings. One for a Clerget type rotary (PP C 9) with a small vent and one for the LeRhône type rotary (PP C 10) with out any vent. In scale drawings the Clerget adds about 1 3/4" to the overall length of the standard F.1 type. Later many of the LeRhône cowlings had additional vents added to their 4 and 5 O’clock positions due to the exhaust valve opening later in the cycle than the Clerget that had the single vent at the 7 O’clock position. Check your references. The instructions try to simplify the concern and show C 10 as one you can modify to a Clerget type if you drill your own hole. Also, the Clerget cowling fillet ( B 6) doesn’t fit well with out some sanding of its mating surfaces for the Clerget cowling (PP C 9.). . ."
