INTAKE MANIFOLDS
Intake manifold conveys the air-fuel mixture to the engine by means of reed valve.
The total efficiency of an engine is calculated as the product of various partial efficiencies, such as:
- volumetric efficiency
- thermodynamic efficiency
- mechanical efficiency
Volumetric efficiency is the ratio between the quantity of fuel that can enter the combustion chamber and the displacement of the engine.
One of the main factors affecting volumetric efficiency is loss due to friction that the fluid encounters (air-fuel mix) when feeding from the air filter to the combustion chamber. Therefore, one of the components that greatly influences this loss is the intake manifold, since all of the mix has to travel through it with the minimum possible loss. For this reason, sudden increases in section and corners along the mix path must absolutely be avoided.
The intake manifold also acts as an accumulation tank for the fresh load, since the mix, travelling at a certain speed, requires time to stop when the reed valve closes. Therefore, mix collects in the manifold and exerts pressure against the reeds. For this reason, each manifold has a well-defined range of revolutions within which it provided maximum efficiency (tuned manifold).
In addition, the manifold supports the carburettor by connecting it to the engine casing or to the cylinder, damping vibrations between casing and carburettor and preventing emulsion of gas and air in the carburettor tank.
This apparently simple component therefore requires a great deal of study in order to take full advantage of all of its qualities.
Malossi engineers have achieved this to perfection. Malossi, with decades of experience in engine fuelling systems, has created a new line of manifolds in rubber and aluminium alloy for the new generation of scooters, and has tested and developed the line on roads and race tracks.
Malossi rubber manifolds feature a composite structure. Their construction begins with an aluminium insert that is encased in a special plastic material that is impervious to oils and fuels, guaranteeing increased rigidity at the point of attachment to the casing and greater flexibility of the manifold body.
Derbi - Minarelli engines : APRILIA - HONDA - PIAGGIO
| Code | Material | INTER-AXIS mm | Ø hole | Ø manifolds | Ø inlet | total lenght | carburettor applications | Note |
| 02 6639B | NBR | 61x40 | 6,5 | 30 | 35 | 27 | PHBH 26-30 VHST 26-30 | Not suitable for original air box filter |
Piaggio - Gilera 2T 50 engines : APRILIA - DERBI - GILERA - ITALJET - PIAGGIO
| Code | Material | INTER-AXIS mm | Ø hole | Ø manifolds | Ø inlet | total lenght | carburettor applications | Note |
| 02 7528B | NBR | 52 | 6,5 | 26 | 30 | 31,5 | PHBL | Not suitable for original air box filter |
| 02 8480B | NBR | 52 | 6,5 | 22 | 28 | 26 | PHVB 22 | For original air box filter |
| 02 5733B | NBR | 52 | 6,5 | 20,5 | 23 | 26 | ORIGINALS PHVA 12-17,5 PHBG 15-21 | Original spare Ø 20: for original air box filter |
Yamaha - MBK - Minarelli horizontal 2T 100 engines : APRILIA - BENELLI - ITALJET - MBK - YAMAHA
| Code | Material | Ø hole | Ø manifolds | Ø inlet | total lenght | carburettor applications | Note |
| 02 8399B | NBR | 6,7 | 22 | 28 | 24,5 | PHVB 22 | For original air box filter |
| 02 8481B | NBR | 6,7 | 21 | 23 | 24 | ORIGINALS PHVA 12-17,5 PHBG 15-21 | Original spare Ø 20: for original air box filter |
Yamaha - MBK - Minarelli vertical 2T 50 engines : APRILIA - ITALJET - MBK - YAMAHA
| Code | Material | INTER-AXIS mm | Ø hole | Ø manifolds | Ø inlet | total lenght | carburettor applications | Note |
| 02 8400B | NBR | 58x35 | 6,5 | 20,5 | 23 | 19 | ORIGINALS PHVA 12-17,5 PHBG 15-21 | Original spare Ø 20: for original air box filter |
| 02 8479B | NBR | 58x35 | 6,5 | 21 | 27 | 19 | PHVB 22 | Not suitable for original air box filter |
Products reserved exclusively for racing in specifically designed locations according to the provisions of the competent sporting authorities. We disclaim all liability for improper use
Vehicle compatibility (29 vehicles)
Aprilia(2)
- AMICO 50 2T
- SR 50 2T ←1993
Italjet(5)
- BAZOOKA 50 2T
- PISTA 2 50 2T
- REPORTER 50
- SCOOP 50 2T
- YANKEE 50 2T
MBK(12)
- BOOSTER 50 2T euro 0-1
- BOOSTER 50 2T euro 2 (A137E)
- BOOSTER NAKED 50 2T euro 2 (A137E)
- BOOSTER NG 50 2T euro 0-1
- BOOSTER NG 50 2T euro 2 (A137E)
- BOOSTER ROCKET 50 2T euro 0-1
- BOOSTER ROCKET 50 2T euro 2 (A137E)
- BOOSTER SPIRIT 50 2T euro 0-1
- SORRISO 50 2T ←1995
- STUNT 50 2T euro 0-1
- STUNT 50 2T euro 2
- TARGET 50 2T
Yamaha(10)
- BW'S 50 2T euro 0-1
- BW'S 50 2T euro 2 (A137E)
- BW'S NG 50 2T euro 0-1
- BW'S NG 50 2T euro 2 (A137E)
- BW'S Original/Naked 50 2T euro 2 2010→ (A137E)
- CRZ 50 2T
- CT 50 2T
- SLIDER 50 2T
- SPY 50 2T
- ZUMA 50 2T
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