1. Dynamics of an IC Engine
Valvetrain
By
Mr. Narayan Sanjay Susange
MIS : 121495019
Under the Guidance of
Dr. D. N. Malkhede (COEP)
Dr. C. M. Sewatkar (COEP)
Mr. Naresh Gandhi (KOEL)
Mr. Aniket Basu (KOEL)
DISSERTATION REPORT
ON

2. Outline
Project definition.
Introduction to Valvetrain.
Literature Review
Steps in Project.
Simulation Work.
Validation.
Design Modification.
Conclusion

3. Project Definition
To study the dynamic behavior of valvetrain system at
elevated 3300 rpm from it’s max rated 3000 rpm.
Further attempt to reduce the dynamic impact of these
elements on performance of valvetrain.

4. Introduction to Valvetrain.
Valve
Valve Seat
Valve Spring
Rocker Arm
Push Rod
Tappet
Camshaft

5. Literature Review
 Dynamic Phenomenon prediction

6. Steps in Project
Literature Review
Modelling Parts in Creo.
FEAAnalysis in HyperMesh.
VALKIN and VALDYN model in RICARDO.
Validate model with experimental results.
Design modification
Interpret results.

7. Need of Project
Typical engine used in fire fighting.
Requirement of high capacity engine is generated from
marketing dept.
Time restriction for building new engine.
Started modifying existing engine to match requirement.
After modification found that valvetrain is weakest
element.
Started generating data with experimentation.

8. Simulation
RICARDO VALKIN and VALDYN.
Dimensional inputs are taken from model.
Mass and stiffness values are taken from FEA model.
Run the simulation at various rpm such 840, 1800, 2600,
3000 and 3300.
Experimental results of pushrod forces at 3000 rpm are
taken validation.
Model Validated.

9. VALKIN
Model
Lift.
Velocity.
Acceleration.
Wear rate.
Contact
Forces.
Contact
stresses.
Oil film
thickness.

11. Lift.
Velocity.
Acceleration.
Dynamic
Forces.
VALDYN
Model

12. Inputs for VALDYN Model
Sr. No. Ricardo Model Components Damping
Stiffness Mass Damping
Coefficient(N/mm) (gm)
1 X support 1750 82642 926.435711 0.1
2 Y support 1750 70744 1082.24726 0.1
3 1/2 rocker + valve 337.9829071 24213.075 209.68 0.075
4 Valve seat 348.4250278 100000 30.35 0.1
5 1/2 pushrod + 1/2 rocker 140.063821 17032.361 115.18 0.05
6 Half pushrod 173.6294385 27531.673 109.5 0.05
7 Camshaft tappet 2402.642295 34000 38.5 1.05
8 Camshaft bending 387.2983346 100000 150 0.05
9 Rocker + pushrod 1/3 387.2983346 100000 150 0.05
10 2/3 pushrod 229.6153616 19841.27 118.1 0.075

13. Pushrod Forces @ 3300 rpm

14. Validation of Simulation Model
-100
0
100
200
300
400
500
600
700
800
0 1000 2000 3000 4000 5000 6000 7000 8000
ForceinN
Time in milliseconds
PUSHROD FORCE
Simulation Model Result Experimental Result
@ 3000 RPM

15. Valve Lift

16. Valve Seat
Force

17. Rocker Valve
Contact Forces

18. Tappet
Force

19. Cam Forces

20. Spring Surge

21. 0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
6.5
7
7.5
8
-5 10 25 40 55 70 85 100 115 130 145 160
CamLiftinmm
Rotation Angle in Deg
Cam Profile
New profile
old profile
Design Modification

22. Spring Surge

23. Valve Lift

24. Valve Seat Forces

25. Rocker Valve
Contact Forces

26. Push Rod Forces

27. Tappet Force

28. Cam Force

29. -50
150
350
550
750
950
1150
1350
1550
1750
1950
2150
2350
2550
2750
2950
3150
0 1000 2000 3000 4000 5000 6000 7000 8000
ForceinN
Time in milliseconds
Old Cam
Updated cam
Pushrod Forces Comparison

30. Sheet Data of Comparison
Model-
2600 half
model
3000 half
model
3300 half
model
2600 half model with
updated cam profile
3300 half model with
updated cam profile
Contact loss Rocker-
Valve
1 2 4 0 1
Jump in mm 0 -0.4 1 0 0.2
Bounce in mm 0.015 0.25 0.4 0 0
Spring Surge in mm 1 2.75 3.6 0.1 1
Push Rod Forces in N 2650 2800 (5.6%) 3080 (16.22%) 1350 (-49.50) 1850 (39.90%)
Valve Forces in N 950 1700 (78.50%) 1350 (42.10%) 680 (-28.42) 1200 (-11.11%)
Tappet Forces in N 2840 3180 (12%) 3250 (14.43%) 1450 (-48.94%) 2050 (-36.92%)
Cam Forces in N 3000 3450 (15%) 3420 (14%) 1500 (-50%) 2200 (-35.67%)
Valve Seat Force in N 2750 2250 (-18.18%) 2300 (-16.36%) 2250 (-18.18%) 1850 (-19.56%)
Valve Seat Bounce pts 2 4 4 2 1

31. Conclusion
At 3000 & 3300 rpm, Valvetrain shows significant dynamic
Effects in terms of Spring surge, Valve jump and bounce,
Pushrod forces and contact loss.
This will definitely affect the valvetrain performance and it’s
life.
Modified cam profile suppresses almost all the unaccepted
dynamic effects which is also a better for normal rpm run.
Further modification in valvetrain parts like pushrod, tappet will
not enhance dynamic effects.

32. Thank you