Must for Intake Manifold Design

          Intake Manifold : Design Process


Process Step 1 - 
Firstly the basic design criteria like cost, weight and life will be analyzed. After freezing basic design criteria, design failure mode effect analysis will be done. Intake manifold is a single unit part but there are so many complicated parts which are mounted on it such as throttle diffuser pipe, MAP Sensor, Resonator, Strength Stiffener. For Intake Manifold Assembly on both end gaskets are used to avoid air leakage. As mass of Throttle is less M6 Bolts can be used for tightening , on the other hand intake mounting on cylinder head M8 Bolt will be better because whole intake mass will work like a simply supported beam, which will cause moment in bolt, specially at high vibration, braking deceleration and starting time, so M8 bolts will be safer. (Note: A – Best/Go, B- Mediocre/Compromise, C- Not Suitable/No Go)


Child Part
Requirement
Material
Manufacturing
Cost
Weight
Life
Design Review
Manifold
Burst Pressure 10 Bar,
Vibration 30 g,
Working Temperature
200 ° C,
Surface Roughness Ra8, Ra16 and Ra32
PA66 GF35
Moulding
C
A
B
PA66 GF35 has low weight but moulding tool will be very costly. Also machining (R8) in plastic is very difficult process, only few suppliers can do it by moulding.
ADC12 will be used for Pressure die casting and then machining will be done. To save cost Sand Casting can be done for making proto part.
By Machining desired surface finish can be archived in ADC 12.
ADC 12
PDC, Machining
A
B
A
Steel Alloy
Machining
B
B
A
Gasket
Working Temperature 300 ° C
Leakage Pressure
10Bar  

Paper
Die Cutting
A
/
C
Circular Rubber Gasket (like O Ring) has better sealing property.  Groove can be made in body of runner plate to mount it on cylinder head. However we will use Paper Gasket as it is easy to design & manufactures and low cost.
Rubber
Compression Moulding
C
/
A
Insert, Collar for Mounting or Nipple for Inlet/
outlet
Compressive Load
1000 N,
Torque 200Nm
No Rusting
Aluminum
Casting
Heat Treatment
Machining
A
C
B
Press fitted brass nipple can be easily assembled in Aluminum Intake Manifold. Separate Brass Collar is not required Aluminum Intake however mounting hole must have high surface finish near Ra16 or Ra 32.
Brass
C
A
A
Steel
B
A
A
Fastener
30 G Vibration
100 N Load
No Rust
M6 Class8.8
Machining,
Heat Treatment,
Thread Making
-
-
-
For Restrictor and MAP Sensor M6 will be used. For Manifold assembly on cylinder M8 will be used.
M6 Class10.9
-
-
-
M8 Class8.8
-
-
-


Step 2 - It is unavoidable to design manifold without DFMEA. Check next article for Intake Manifold DFMEA ( Design Failure Mode Effect Analysis)