Volksforum.com - 1600 of 1641

10-04-2006, 10:53

Flitz

Forum Newbee

Join Date: Apr 2006

Posts: 2

1600 of 1641

ik heb even een vraagje , ik ben mn blokje 1600 cc aan het reviceren en voor het goede moet ik nieuwe zuigers, cilinders e.d. .
nu twijvel ik tussen 1585 en 1641 cc en gesmede of gegoten zuigers?

heeft iemand hier ervaring mee?

merk je het verschil en is het echt beter , sneller en of sterker

groetjes Remon
1971 t2a

10-04-2006, 11:21

Stijn

Class of 2003

Join Date: Dec 2003

Posts: 8,760

Gesmede zuigers zijn eigenlijk alleen nuttig als je voor extreem vermogen gaat. Ze zijn sterker uiteraard, maar vergen bijvoorbeeld een grotere tolerantie tussen cylinder en zuiger door een grotere uitzetting bij hitte t.o.v. gegoten. Dit veroorzaakt op zijn beurt dan weer veel meer mechanisch geluid.

Voor gewoon dagelijks weggebruik zou ik altijd voor gegoten zuigers gaan. Gesmeed is voor dit gebruik gewoon overdreven, oncomfortabel (geluidsniveau) en veel te duur.

Quote:

Pistons (or slugs as they are sometimes referred to) reside in the cozy inferno under the combustion chamber of the cylinder. Attached to the small end of the connecting rod, these units move up and down in the cylinder at tremendous speeds pushing air in and out of the engine. Most engines, even performance-minded motors, come from the factory with some sort of cast aluminum pistons. There are both high- and low-pressure cast pistons and their resistance in a hostile cylinder environment is relative to the density of their composition and its related resistance to friction and pressure. Simply put, cast pistons cannot withstand the levels of heat, friction, and speed that aluminum forgings, with their denser mass, can survive. Casting is a mass production process that allows for minute imperfections and porosity in the piston. Cast pistons, which are stock in popular motors, are often high-pressure castings with friction-fighting coatings to survive more revs. The advantages of cast pistons are that they’re lightweight, there’s a lower thermal expansion rate compared to forgings, and they cost less. For most mild performance applications, these castings are quite effective due to their lower heat conductivity and tendency to reflect heat back to the combustion chamber.

Hypereutectic pistons became the rage in the early ’90s as they offered the reliability and light weight of cast pistons but were resistant to higher cylinder temperatures. These pistons are cast with a material high in silicone content to achieve the low expansion rate and cylinder wall tolerance of a common cast piston, with near forged piston strength. Hypereutectic pistons are ideal for high-performance, naturally-aspirated combinations that won’t suffer under the strain of power adders like turbos or nitrous, which can quickly decompose this strong, but inflexible style of piston. These pistons are priced in between pressure castings and forgings.

Forging is a process that creates a solid chunk of uniformly grained metal. The details, features and sizes are then precision-machined from this piece to create a near jewel-like finished product. Forged pistons come from the aftermarket in various sizes, pin and ring locations, and dome configurations. Forged pistons signify a serious commitment to the engine’s performance potential; their ability to withstand heat and pressure at greater speeds inevitably means greater outputs than cast pistons. Most forged piston manufacturers offer two different alloys as the base material for the forged pistons. Forged pistons become stable at higher rpms, once their material expands, but can cause noise as they slap around in the cylinder walls at low speed when cold. The aluminum used for forged pistons differs in its proportion of silicone and copper, and thus offer different expansion rates. Additional silicone in a 4032 grade alloy yields a piston with lower heat expansion properties that maintains a tighter piston to wall clearance. Another grade of aluminum, 2618, contains less than one percent silicone with a higher content of copper. The composition of such pistons permit greater expandability and require greater piston-to-wall clearances, making it suited for the extreme heat and pressure caused by high-boost turbos, superchargers and loads of nitrous.

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10-04-2006, 15:31

-Jens!-

Forum junkie

Join Date: Dec 2003

Posts: 1,754

als ik jou was zou ik gewoon voor de 1585 gaan, zo heb je een betrouwbaar blok met een goede ''dikke'' cilinderwand staan. busblokken krijgen zowieso al meer op hun flikker, 1641 als ook de 1835 cilinders staan bekend om hun problemen door de te dunne cilinderwand.....

merkbaar verschil is er niet n pk's...

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