rossi piranha engine -...
TRANSCRIPT
Rossi 21 Piranha
This is an exclusive review of the Piranha marine engine
08/11/2001updated 11/25/2001
The new Rossi Piranha engine 2001, which is distinguished by the outside design, has a standard construction. However, when you open the engine, you discover some interesting technical options.Come with us to discover the heart of this wonder.
RPM 42 000
Stroke: 16.48 mm
Bore: 16.44 mm
Capacity cubic:
3.5 cc
The engine, in which the crankcase has an ovoid design, can't be merged into any other engines.When you open the box, you have :
● Marine crankshaft,
● A watercooled jacket,
● Carburettor
• Crankcase :
The design of the crankcase is specific to Rossi.Notice the negative angle of the exhaust port, in order to improve the gas flow.To fix the engine on your gearbox, the distance between the screw (diameter 3mm) is the same as R&B, Nova Rossi, Picco and CMB.This crankcase, appears to be heavy, but when you weigh it, it is no heavier than any other engine.
• Back Busch :
It has a groove for the piston and a joint.
Two clearings improve the gas flow.
• Ports :
A lot of work has been done.When you put the liner on the crankcase, the ports are exactly opposite each other.
There are two grooves, just upon the ballbearing, in order to improve the gas flow between the ports.
• Piston/liner :
The piston is fully machined in a special ceramic alloying. We have no more information, as it's top secret !The ceramic improves the sliding friction between piston/liner.Moreover, the piston has a better size stability when the temperature increases. It expands a bit.
The machining is excellent. On the face of the by-pass, in the liner, you have 4 big holes in the piston.There is a clearing just under the induction port to improve the gas flow. This provides a better route for the gas between the ballbearing and the back of the liner.
• Conrod :
The conrod uses a classic design.
• Crankshaft :
The crankshaft is designed as a propeller with a groove.Particularity : the crankshaft is chromed and mirror polished (option).The goal of this work is to improve the gas flow, which comes from the carburettor to the crankcase. With this work, you prevent the turbulent flow created by the roughness of the steel. You get a laminar flow and don't lose capacity.Moreover, the turbulent layer on the crankshaft surface created by the roughness, decreases the useful capacity.
• Watercooled jacket :
The header is equipped with a watercooled jacket, with a very small capacity.
The screws are kept out the water.
The glow plug is conical; in shape.
• Carburettor :
It has a ring in order to remain colder than the rest of the unit.
Note : very nice venturi
Arnaud Cardinale's engine assembly
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Copyright © 2001 Xavier Cardinale