I happen to be fortunate enough to have a technical manual for the Clerget engine written in 1918 as an teaching manual for the mechanic/pilot who plans to work on and use this engine.

Bold text110 H.P. CLERGET ENGINE

GENERAL DESCRIPTION. This engine is of the rotary air cooled type, with 9 cylinders, 120m.m by 160 jm.m, rated at 110 H.P., but capable of developing 130 H.P. at 1,200 R.P.M. It is fitten with a double thrust ball race, which enables it to be used either as a pusher or as a tractor. aThe engine works on the Otto, or 4 stroke cycle, 2 revolutions of the engine giving 1 cycle (4 strokes) in each cylinder. Its chief points of difference from other rotary engines are.

 (1). The pistons are of aluminium alloy. (2). The connecting rods are of tubular section. (3). The inlet and exhaust cams are mechanically operated by means of sparate cams, tappets and rocker arms. 

The direction of rotation is anti-clockwise as seen from the propeller end of the engine. Like all other rotary engines it is made chiefly of steel, for strength and lightness. The angle through which the engine turns between any 2 consecutive explosions is 80 degrees.

 (there are more pages and pictures) The book is "Air Board" Technical Notes issued by Controller Technical Department for persons holding an official position in His Majesty's Service dated 1918 

Approx oil consumption =2 galls. per hour.

 " petrol comsumption - 10 galls per hour. " weight of engine - 365 lbs,i.e. 3.3 lbs per rated H.P.