Engine with reduced noise

An engine comprising:

• a crankcase that has an opening portion in a lower portion;
• an oil pan connected to the lower portion of the crankcase so as to block the opening portion;
• and
• an oil strainer including a pipe member and a case member, wherein
• the crankcase includes a reinforcing plate portion formed integrally with the crankcase so as to span the opening portion,
• the reinforcing plate portion includes two bolt holes and a through hole between the two bolt holes,
• the case member has an inlet port and an outlet port, and fixed to an upper surface of the reinforcing plate portion such that the inlet port communicates with the through hole,
• the pipe member is fixed to a lower surface of the reinforcing plate portion so as to communicate with the through hole,
• the oil strainer and the reinforcing plate portion are attached by respective bolts inserted into the respective two bolt holes, and
• the crankcase includes a first rib portion extending from a first edge of the opening portion to the reinforcing plate portion, and a second rib portion extending from a second edge of the opening portion to the reinforcing plate portion.