The purpose of this major qualifying project (MQP) is to design and manufacture an engine head that allows for the variation of the compression ratio for a lawnmower engine. This engine will be used as a classroom demonstration tool for the Worcester Polytechnic Institute (WPI) Mechanical Engineering Department. The engine must be able to run safely in a classroom setting and have the ability to adjust the compression ratio between 2:1 and 7:1 while the engine is running and able to withstand sub-optimal operating conditions. Other requirements include easy transportation to and from the classroom, and the ability to easily adjust the compression ratio. The design focuses on modifying a lawnmower engine and replacing the cylinder head with a movable piston mechanism that allows the user to vary the head volume, while the engine is running; thus, changing the compression ratio. The design of the engine head mechanism was completed, and the majority of the parts were manufactured almost entirely in WPI’s Washburn Shops out of cast iron with the exception of a few parts being purchased on McMaster-Carr. The mechanism consists of an outer housing, a plunger, and an Acme rod subassembly that allows the plunger to be raised and lowered. Moving the plunger up and down changes the volume above the engine piston and thus the compression ratio. The team was able to manufacture the entirety of the engine head mechanism except for the plunger which needs only one small modification to complete.

• This report represents the work of one or more WPI undergraduate students submitted to the faculty as evidence of completion of a degree requirement. WPI routinely publishes these reports on its website without editorial or peer review.

Creator

• Damle, Siddhant
• Turetsky, Dylan
• Riley, John
• Arbore, Michael

Publisher

• Worcester Polytechnic Institute

Identifier

• E-project-042722-214728
• 64781

Keyword

• Cast Iron
• CNC Machining
• Computer Aided Design
• Engine
• Compression Ratio

Advisor

• Daniello, Robert

Year

• 2022

Date created

• 2022-04-27

Resource type

• Major Qualifying Project

Major

• Mechanical Engineering

Rights statement

• In Copyright