<VV> 64 turbo acceleration issues

[Mikeamauro at aol.com]

I've been monitoring this conversation since inception, and don't recall  
seeing the OEM fuel filter, or fuel return system, being discussed... could 
have  been, and may have missed it, but... I owned a 64 Spyder from 1974 
until just  recently. From the time I bought the car, until the mid 1990s when 
it was  restored, the car was my daily transportation. I, too, experienced 
Carter YH  carb fuel-cluster dribble; I also experienced loss of power (i.e.: 
symptoms of  fuel starvation) under acceleration. The stock fuel filter has 
a return line  leading back to the fuel tank inlet spout. The primary 
purpose of the  return system is to continually allow "refreshment" of the fuel at 
the filter,  thus keeping the fuel headed to the carb relatively cool. The 
second advantage  of a working fuel return system is it (the system) acts in 
 a pressure relief capacity, in that the tubing going back to the fuel tank 
 spout is (when working as designed) fully open... when engine shuts down,  
pressure is relieved back to the tank. Page-47, of the Clark's 2007-2012 
main  catalog, contains a succinct explanation of what I just expressed,  
verbosely...see: "FUEL RETURN LINE."
 
I corrected my Carter YH woes by: 1) replacing the standard carb needle and 
 seat with a "Grose Jet" metal ball style fuel inlet valve assembly 
(Clark's  part#: C3800); lowering the float level setting slightly from stock 
(about  1/16"); insuring the fuel filter was not fouled (this required periodic 
filter  changes, being sure to use a filter with the return line feature, 
only!); making  certain the fuel return system was functional (listening at an 
uncapped fuel  tank spout, with engine idling, one should be able to hear 
fuel dribbling back  into the spout from the return system). My return system 
was, upon purchase of  the car, non-functional: the rubber return line was 
pinched shut at a  mounting clip... I replaced all return components; altered 
the carb as  previously described, and the return system and carb were 
"golden"  thereafter, for decades, and remained so at sale of vehicle. Never had 
 to add a fuel pressure regular.
 
Mike Mauro
Of numerous Corvairs since 1970