Carburatore + Spinterogeno: richiesta pareri

[Guest]

allora ti comperi un 650 manuale qualche getto di riserva e vai a far festa .

[bronzo]

[nigel68]

[quote name='bronzo' post='285900' date='23/4/2010, 21:07']Molti motori americani nascevano 2bbl con il 4bbl opzionale. medesimi motori...potenze differenti.



Questo voglio vedere come me lo spiega qualsiasi CFM calculator.[/quote]



Nel caso del Ford 302 Windsor del 68 (ma ? un esempio) la versione 2V aveva 9:1 di compressione e utilizzava benzina normale. Lo stesso motore in configurazione 4V aveva camere di combustione di diverso disegno, rapporto di compressione portato a 10:1 e necessit? di benzina premium. Probabilmente in altri casi e per altre marche, il carb maggiorato portava con s? anche altre modifiche e poi non sono solo i Venturi che contano, ma appunto i CFM, per cui non ? detto che passando da un 2V a un 4V il valore raddoppiasse.

Ad esempio, sempre nel caso del succitato Windsor:

2V - Autolite 2100 - 1.08- 287/300 CFM

4V - Autolite 4100 - 1.08 - 480 CFM



Infine una citazione:

"For years, people have had the notion that "bigger the better?. That concept is simply not true. What happens is that when too large a carburetor is installed, low end performance suffers without any appreciable gain in top end performance. An oversized carburetor will run ?lean? off idle through the normal range operating range and then dump too much fuel at the top end, and run ?rich?. A correctly sized (and functioning) carburetor will provide a constant air/fuel ratio through most of the operating range.



The idea is to choose a main body with a large enough bore and venturi area to allow maximum airflow through the carburetor and into the engine. At the same time, however, these areas must also be properly sized to promote a high-speed airflow signal into carburetor, a measurement of air speed that the carburetor reads in order to determine how much fuel to deliver to the incoming air stream. In theory, if the bore and venturi are too large, the signal will be weak at low engine speeds and the fuel will not be pulled from the carburetor's discharge ports accurately. The opposite of this effect is when the carburetor's bore and venturi are too small for the engine's airflow demands. While throttle response will be outstanding, the engine's maximum airflow, or power potential, will be diminished. The ideal carburetor sizing combination will be able to move the maximum amount of airflow through the carburetor while maintaining the strongest possible signal.



Therefore, it is very important to use a CFM calculator, thus ensuring you have selected the proper size carburetor for your CFM requirements" Fonte: Classicinlines

[bronzo]

Traducimelo....altrimenti ci metto mezz'ora e non ho tempo!