Re: alfa-digest V7 #949 - Vapor Separator on carb-converted Alfa

[AlfaNeely@domain.elided]

In a message dated 08/09/1999 10:50:46 AM Central Daylight Time, 
owner-alfa-digest@domain.elided writes:

<< Date: Mon, 9 Aug 1999 09:19:44 -0400 
 From: "Idleman, Christopher" <CIdleman@domain.elided>
 Subject: Vapor Separator on carb-converted Alfa?
 
 On SPICA-injected spiders, there is a hose that runs from the bottom of the
 "vapor separator" (mounted on the passenger side near the front of the
 engine bay) to a port on the airbox.  I presume that this is to allow fuel
 vapor from the separator to be drawn back through the air intakes.  On cars
 that have been converted to carbs, what is typically done with this line?
 Is it plumbed into the carb air inlets (through the filter lids?), is it
 plumbed into the fuel/vapor return line running back to the fuel tank, or
 something else?  What is the standard configuration on factory-carbureted or
 Euro-spec cars?
  >>

    Plug it up, cut it off so it vents to the open air or plumb it into the 
air cleaners.  The car will run the same either way.  Plugging may cause a 
vacuum in the gas tank and venting to the air is not good pollution wise.  It 
is probably best to vent it into the air cleaners.  It will not hurt 
performance and will help prevent smog, so that is best.
    Be aware that the fuel return line from the Spica pump back to the tank 
needs to be plugged off.  Carbs do not need to return excess fuel to the gas 
tank.  I guess you could also plumb this line into the air cleaner, but it is 
probably better to disconnect it at the pump in front and plug it where it 
enters the gas tank.  You can remove the return line to save a minimal amount 
of weight.
    Also, the Spica fuel pump produces much too much pressure for the carbs.  
Carbs like about 3 pounds of fuel pressure.  Buy an after-market electric 
fuel pump and maybe a fuel pressure regulator.
    You can use the big fuel filter canister in front.  If you notice the 
filter housing has provision for two inlets and two outlets.  You can screw 
an extra nipple into the second outlet and plumb from the Spica fuel filter 
directly to each carburetor.  The disadvantage is the cost of the Spica fuel 
filters.
Ciao,
Russ Neely
Oklahoma City

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End of alfa-digest V7 #952
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