<VV> Tech question - Turbos & carbs

[Sethracer at aol.com]

Lately, I have been getting hesitation when I jump on it. I plan to  
rebuild 
the carb in the next week or so. 

I recently purchased a box  of assorted Corvair parts. In that box among 
others was a # 40205 Carter YH  carb. I understand that it is a 1965 -180 
carb which has a 1-3/8" main  venturi verses my '64 1-5/16 venturi. I also 
got two turbos. One is a 1963  #3830551 and the other is a 1965/66 
#3856709. 
They both turn freely with my  finger. 

I have read Bob Helt's "The Classic Corvair " (great book Bob,  thanks). I 
understand that if I rebuild the two spare turbos and use the  exaust side 
from the 63 and the intake from the 65 I can expect better  performance. It 
seems to me that if I use the larger 65 intake turbine I  should also use 
the 
larger 65 carb. 

As I said, my current 64 carb needs to be rebuilt. Would I see any issues  
if 
I rebuild the 65 Carb and use it with my current 64 turbo? I don't have  
all 
the tools to rebuild the turbo at this time. 

Also, It seems to  me that the primary difference between the 64 150 turbo 
and the 
65/66 180  turbo is the carb and the turbo. Wouldn't changing out the carb 
and turbo as  I discussed above essentially give me 180 performance? 




Dave - The 180 "performance" was mainly a marketers dream. But you  would 
probably get better performance with the larger carb. The YH carb is a  
fairly simple carb, but a "Pain" to get right after rebuild. There are a bunch  
of little tips on getting it "right" . Frank passed along some good sources. 
The  turbos are referenced by their flow ratings. the 62-64 is called a 
"B-flow", the  65-66 is called an "F-flow" You can combine parts, usually the 
exhaust side of  the B-flow and the intake side of the F-flow to get a bit 
better response. There  are a couple of other options. Crown manufacturing made 
a pair of exhaust  housings, (three actually, but that is another story) 
with a better A/R ratio.  This provided a slightly better exhaust side 
spool-up, helping boost to come in  earlier. These housings still bounce around the 
aftermarket. They look stock,  and bolt on, but they do not have the holes 
to support the air feed to the  YH choke, so you might have to jury rig 
something for that. 
 
One important note if you do decide to rebuild the Turbocharger - The nut  
that retains the intake compressor scroll is a left-hand thread. Don't  
forget this! Also, there is a neat new tool for disassembly of the Turbo, it is  
a machined assembly that accepts the exhaust scroll and holds it in place 
to  allow the other parts to be worked on. 
 
I suggest you rebuild the 65 carb, install it and see if the  hesitation 
goes away. Get it working fine - before you start swapping other  parts. 


Seth  Emerson

C's the Day! - Corvair, Camaro,  Corvette