<VV> RE: Was: please post for me, Now: 4bbl driveability

[Craig Nicol]

<snip>I just started restoring my '67 that I picked up a few months ago. It
is a 4speed car with a 110 but has a 4 barrel carb setting on it. All I have
done is start it up and drive it around the block a few times. Needs brakes
and I'm workinh on them. 
  Does anyone have any idea how these 110's run with a 4barrel or know
anything that I should know about them. It also has headers with glass
packs.... Any help would be nice. Thank you in advance, Joe <unsnip>

Thanks for posting, Joe, and WELCOME!

The 110 / 4bbl / headers combination will provide good mid-range and
improved power as the engine approaches red-line.  The 110 heads with their
smaller intake and exhaust valves won't provide quite the same upper rpm
performance as a 140 though.  

The stock 110 and 140 engines had the same camshaft (stock) but your engine
may have a hotter cam, but hopefully not much more than stock 'cause most
4bbl setups have poor low end driveability and a cam that's much hotter than
stock amplifies that issue.  

The "advantage" of the 4bbl setup is the elimination of linkage and
synchronization issues.  

The disadvantage(s) are poor cold driveability, reduced low speed power,
likelihood of incorrect jetting and transitions, sometimes goofy linkage,
and mismatched choke action. If it's a Holley, fuel leaks are common with
aged carburetors. Most 4bbl carburetors have way too much flow capability
and as a result don't meter well at the Corvair's CFM.  The smallest AFBs
(425 CFM?) and the smallest Holley (390 CFM) seem to be what most successful
conversions have used.  The Quadrajet, due to its small primary bores and
vacuum secondary, can be OK as well.

I've had Corvairs with the 4bbl setup and a "hot" cam that were virtually
powerless below 2500 and barely idled at 1200.  On the other hand, many
years ago I had one with a 390 Holley and a near-perfect setup that ran
extremely well (140 Solar Sprint), but that was in a warm climate
environment.

If you live in a warm-climate and the conversion is well executed, it can be
very satisfying.  If the above is not the case, you might need to spend some
time to "make it right" or seek an alternative. The setup has some potential
though more often than not, they are not well designed or executed.
Craig Nicol
'65 '66 '67 '68