Honda Engine Repackaging 2016

Our goal was to repackage a Honda CRF-150r into a two cylinder electric hybrid.'''

=Problem Statement=

To maintain a competitive advantage in the Formula Hybrid SAE competition, a new exotic and legendary engine design is needed for the University of Idaho race car. The solution is to reverse engineer a Honda CRF-150r one-cylinder engine with computerized micro measuring and laser scanning technology and turn it into a two-cylinder 250cc engine.

=Problem Definition=

Background

The Formula Hybrid team at the University of Idaho is in need of a new engine configuration to remain competitive for future competitions. To incorporate the electric motor and maximize engine displacement, a new engine must be designed that has separate engine cylinders. This will require research of an engine with comparable features and design.

Deliverables

One of the main goals of this project was to reverse engineer the Honda CRF-150R engine, while this process took place we documented any findings we made as well as how we took apart the engine. This project required more than just reverse engineering the engine but also required that we learn to use the metrology equipment and Solid Model the engine using the CAD program Solidworks. The Metrology equipment we used included calipers, CMM, laser scanning technology and scaled photographs.

The second goal of the project was to combine CRF-150r engines together and reduce their displacement to a total displacement of 250 cc. The original CRF-150r is a 150cc, so that meant altering the crankshaft of each engine. We designed a configuration with the engines parallel to each other and with the engines co linear. The configuration of the parallel engines is based of a gear box design from another project relating to a Yamaha engine.

=Specifications= Metrology

CAD Modeling

We had multiple methods for drawing complex parts in Solidworks.
 * (1) We used the metrology equipment to find shape sizes and scan the most difficult parts.
 * (2) We used scans and photographs to trace in Solidworks. Solidworks also has an auto trace function that is useful. We used this for doing the logo on the valve cover.
 * (3) To draw the shift drum we were able to roll its design on piece of paper and then turn that into a 3d model after tracing it.

=Matlab Simulation= The 150cc CRF-150r needs to be modified to a 125cc and fuel injected. We investigated building air fuel ratio (AFR) maps and optimizing spark timing. These images show theoretical power curves and brake specific fuel consumption (BSFC) for a 125 cc version of our engine. By reducing the engine size, a power loss of about 4 hp should be expected.

Following is the dimensions required to make our 150cc into a 125cc, these dimensions were used in the Matlab model: L = (36.5/1000) Stroke of Engine [m], B = (66/1000)   Bore of Engine [m], l = (75.4/1000)         Length of Engine Connecting Rod [m], C_r = 11.8       Compression Ratio, IVC = 0          Time [degrees] when Intake Valve Closes, EVO = 314       Time [degrees] when Exhaust Valve Opens

=Reconfiguration= After modeling was completed the next task was to reconfigure the motor for potential formula hybrid competitions. This configuration places the crankshafts parallel to each other. The power is then transmitted from each crankshaft and the electric motor to a ring gear on the flywheel. From there the power goes out to the wheels thru a differential. Some issues with this include creating enough room for an air intake and considering if a balance shaft is necessary.

We also considered a configuration where the crankshafts would be coaxial. In this case we would build a new crankshaft that served both pistons. In between the engines along the crankshaft there would be room for an electric motor.

=Notable Resources= Copies of all resources are located on the shared drive: S:\Engineering\SeniorDesign\- Senior Design\2016 Summer & Fall\DoublExotic\Research

We considered the effects of having to use an air restricter:
 * Singhal, Anshul, and Mallika Parveen. "Air Flow Optimization via a Venturi Type Air Restrictor." Proceedings of the World Congress on Engineering 2013. Web

Information on basic engine principles:
 * Soruşbay, Cem. "COMBUSTION in SI ENGINES - Internal Combustion Engines – MAK 493E." Istanbul Technical University. Web.

Information for changing the displacement of our engine and more:
 * Burgess, Dave. "Gasket Thickness Decisions." Garlock Sealing Technologies. 2003. Letter.


 * Becker, Stephan, Peter Farnum, Jacob Morissette, and Dwight Whitney. "University of Maine FSAE Engine Team - Preliminary Intake Design."


 * Pitsch, Heinz. "Laminar Premixed Flames: Kinematics and Burning Velocity." CEFRC Combustion Summer School 2014. Institut fur Technische Verbrennung.

We were concerned that the valve seats on our engine were worn, we consulted this resource:
 * "Valve Face Wear or Guttering and Valve Head Tuliping/Cupping." Service Engine Bulletin. Australia Engine Technical SB018.

=Team Members=

=Document Archive= Documents (Meeting Minutes, Agendas)

Our Solidworks files are located on the UofI shared drive: S:\Engineering\SeniorDesign\- Senior Design\2016 Summer & Fall\DoublExotic\CRF150R_HONDA\Modeling Package

The files are organized according to their Honda part numbers. Anyone can find a file by knowing the Honda part number or referencing the repair manual to obtain a part number.