Momentum - February 2021 - 11

Student Generation

NOx emissions data collected from various cam phasing
positions. Refer to Table for legend.

Cutaway of modified cylinder head with engineered valve cover, custom camshaft, and cam
phaser.

The 2020 competition brought many challenges to the team. One
major challenge was the ambition to do what no other CSC team has done:
implement a prototype VVT system into a powersports engine for better
engine control. The specific type of variable valve timing the team worked on
is called variable cam timing (VCT) and was developed by the team with the
help of BorgWarner. The basic idea of a VCT system is to alter when the
valves open and close relative to the crankshaft. This is achieved by phasing
the camshaft to advance or retard the valve timing in real-time using a cam
phaser.

Due to the complexities of such an ambitious project, the team
decided to only apply the VCT system to the intake camshaft. Gamma
Technologies' GT Suite was utilized to determine which camshaft would
better control engine emissions, efficiency, and rideability. This 1D full engine
simulation was a major project for the UMD Clean Snowmobile Team and was
used for turbo selection as well as intake and exhaust designs. It showed that
phasing the intake camshaft in this application would better suit the team's
goals in emissions, efficiency, and rideability. On top of the complex and indepth simulations, the team also was able to manually phase both camshafts
to measure the difference in emissions on their engine dynamometer and
Horiba 5 Gas Analyzer. This testing helped to confirm the results of the
simulations by correlating the emissions data gathered to the simulated
data. It also further helped prove the case for phasing only the intake
camshaft. It also provided a starting point for where in the RPM and load
range to phase the camshaft, and in which direction.

The cam phaser selected was Cam Torque Actuated (CTA) phaser
from BorgWarner and was modified to work with the sprocket and valvetrain
of the ProStar 1000. This style of phaser utilizes the rotational inertia of the
camshaft to aid phasing, resulting in a responsive actuation rate and low oil
consumption, both of which are critical for an engine in a powersports

MOMENTUM

CO emissions data collected from various cam phasing
positions. Refer to Table for legend.

HC emissions data collected from various cam phasing
positions. Refer to Table for legend.
OEM intake and exhaust cam timing
Advanced one tooth intake and OEM exhaust
OEM intake and one tooth retard exhaust
OEM intake and two teeth retard exhaust
Advanced one tooth intake and retard one tooth exhaust
Advanced one tooth intake and retard two teeth exhaust

February 2021 11

Momentum - February 2021

Table of Contents for the Digital Edition of Momentum - February 2021

Momentum - February 2021 - Cover1
Momentum - February 2021 - Cover2
Momentum - February 2021 - 1
Momentum - February 2021 - 2
Momentum - February 2021 - 3
Momentum - February 2021 - 4
Momentum - February 2021 - 5
Momentum - February 2021 - 6
Momentum - February 2021 - 7
Momentum - February 2021 - 8
Momentum - February 2021 - 9
Momentum - February 2021 - 10
Momentum - February 2021 - 11
Momentum - February 2021 - 12
Momentum - February 2021 - 13
Momentum - February 2021 - 14
Momentum - February 2021 - 15
Momentum - February 2021 - 16
Momentum - February 2021 - 17
Momentum - February 2021 - 18
Momentum - February 2021 - 19
Momentum - February 2021 - 20
Momentum - February 2021 - 21
Momentum - February 2021 - 22
Momentum - February 2021 - 23
Momentum - February 2021 - 24
Momentum - February 2021 - 25
https://www.nxtbook.com/smg/sae/21MOMP02
https://www.nxtbook.com/nxtbooks/sae/20MOMP11
https://www.nxtbook.com/nxtbooks/sae/20MOMP10
https://www.nxtbook.com/nxtbooks/sae/20MOMP09
https://www.nxtbook.com/nxtbooks/sae/20MOMP04
https://www.nxtbook.com/nxtbooks/sae/20MOMP03
https://www.nxtbook.com/nxtbooks/sae/20MOMP02
https://www.nxtbook.com/nxtbooks/sae/19MOMP11
https://www.nxtbook.com/nxtbooks/sae/19MOMP10
https://www.nxtbook.com/nxtbooks/sae/19MOMP09
https://www.nxtbook.com/nxtbooks/sae/19MOMP04
https://www.nxtbook.com/nxtbooks/sae/19MOMP03
https://www.nxtbook.com/nxtbooks/sae/19MOMP02
https://www.nxtbook.com/nxtbooks/sae/18MOMP10
https://www.nxtbook.com/nxtbooks/sae/18MOMP03
https://www.nxtbook.com/nxtbooks/sae/18MOMP02
https://www.nxtbook.com/nxtbooks/sae/17MOMP11
https://www.nxtbook.com/nxtbooks/sae/17MOMP10
https://www.nxtbook.com/nxtbooks/sae/17MOMP09
https://www.nxtbook.com/nxtbooks/sae/17MOMP04
https://www.nxtbook.com/nxtbooks/sae/17MOMP03
https://www.nxtbook.com/nxtbooks/sae/17MOMP02
https://www.nxtbook.com/nxtbooks/sae/16MOMP11
https://www.nxtbook.com/nxtbooks/sae/16MOMP10
https://www.nxtbook.com/nxtbooks/sae/16MOMP09
https://www.nxtbook.com/nxtbooks/sae/16MOMP04
https://www.nxtbook.com/nxtbooks/sae/16MOMP03
https://www.nxtbook.com/nxtbooks/sae/16MOMP02
https://www.nxtbook.com/nxtbooks/sae/15MOMP11
https://www.nxtbook.com/nxtbooks/sae/15MOMP10
https://www.nxtbook.com/nxtbooks/sae/15MOMP09
https://www.nxtbook.com/nxtbooks/sae/15MOMP04
https://www.nxtbook.com/nxtbooks/sae/15MOMP03
https://www.nxtbook.com/nxtbooks/sae/15MOMP02
https://www.nxtbook.com/nxtbooks/sae/14MOMP11
https://www.nxtbook.com/nxtbooks/sae/14MOMP10
https://www.nxtbook.com/nxtbooks/sae/14MOMP09
https://www.nxtbook.com/nxtbooks/sae/14MOMP04
https://www.nxtbook.com/nxtbooks/sae/14MOMP03
https://www.nxtbook.com/nxtbooks/sae/14MOMP02
https://www.nxtbook.com/nxtbooks/sae/13MOMD1101
https://www.nxtbook.com/nxtbooks/sae/13MOMD0930
https://www.nxtbook.com/nxtbooks/sae/13MOMD0830
https://www.nxtbook.com/nxtbooks/sae/13MOMD0401
https://www.nxtbook.com/nxtbooks/sae/13MOMD0301
https://www.nxtbook.com/nxtbooks/sae/13MOMD0201
https://www.nxtbook.com/nxtbooks/sae/12MOMD1031
https://www.nxtbook.com/nxtbooks/sae/12MOMD0928
https://www.nxtbook.com/nxtbooks/sae/12MOMD0831
https://www.nxtbook.com/nxtbooks/sae/12MOMD0330
https://www.nxtbook.com/nxtbooks/sae/12MOMD0228
https://www.nxtbook.com/nxtbooks/sae/12MOMD0128
https://www.nxtbook.com/nxtbooks/sae/11MOMD1028
https://www.nxtbook.com/nxtbooks/sae/11MOMD0929
https://www.nxtbook.com/nxtbooks/sae/11MOMD0829
https://www.nxtbook.com/nxtbooks/sae/11MOMD0331
https://www.nxtbook.com/nxtbooks/sae/11MOMD0225
https://www.nxtbook.com/nxtbooks/sae/11MOMD0128
https://www.nxtbook.com/nxtbooks/sae/10MOMD1029
https://www.nxtbook.com/nxtbooks/sae/10MOMD0930
https://www.nxtbook.com/nxtbooks/sae/10MOMD0831
https://www.nxtbook.com/nxtbooks/sae/10MOMD0331
https://www.nxtbook.com/nxtbooks/sae/10MOMD0226
https://www.nxtbook.com/nxtbooks/sae/10MOMD0129
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