on another throw a conventional connecting rod 29 has its upper end journaled on wristpin 31 carried on piston 22 and its lower end journaled onto a crankpin 32 mounted on crank throws 33 and 34 the crankshaft throw 33 is here incorporated into and forms part of a lubrication splash gear 36 having peripheral teeth 37 an oil reservoir pan 38 is removably secured to the bottom of the cylinder block 19 by bolts 39 and is formed to provide a u shaped trough 41 through which the lower portion of gear 36 passes trough 41 confines and channels the action of gear teeth 37 to accomplish improved lubrication preferably cam 11 is secured to the side of splash gear 36 opposite to crank pin 32 in the manner best seen in fig1 and 3 of the drawings as cam 11 rotates with crankshaft 12 the cam lobe 42 urges upwardly the assembly consisting of cam follower roller 17 lifter rod 13 valve stem 14 and valve head 43 to admit air through passage 23 into the combustion chamber 24 and cylinder 21 as may best seen in fig5 cam lobe 42 is positioned so that valve 16 starts to open before piston 22 uncovers exhaust port 28 when the combustion takes place in chamber 24 the rapidly explanding gases.