tigers
[Top] [All Lists]

Re: carb adjustments

To: "Daniel S. Eiland" <deiland1@elp.rr.com>
Subject: Re: carb adjustments
From: Steve Laifman <laifman@flash.net>
Date: Sun, 10 Oct 1999 16:07:50 -0700
"Daniel S. Eiland" wrote:

> Steve,
>     Well, I pulled the carb and went out and bought a Holley book by Haynes.
> I have adjusted the floats, primary and secondary, air/fuel mixture 1 1/2
> turns, the secondary 1/2 to 3/4 turn,  and backed the choke adjustment all
> the way out. At this point the idle stays around 1500 RPM but sounds great.
> Took it out to test it and the car is sluggish from a standstill but you can
> sure feel the secondary kick in.

Actually, it should be a very smooth transition, with no 'bogging' or sudden
increases,
or something isn't adjusted properly.  The concept is not that it 'kicks-in', 
but
gives you all
the power you need at any speed, with no transition effects, as it is already
constantly peaked.
The Manual secondary type carb can appear this way, but what is really happening
is that the
car is bogged down by two slow an air/fuel velocity until you reach a load and 
rpm
that matches
where the throttle plates are opened to, then the carb starts mixing and flowing
properly.
You think you've hit a power surge, but you've really just gotten out of a power
loss.  A well
carburetted engine will just keep putting out more and more smooth power, with 
no
sudden changes.

> I removed all the manifold carb mounting
> bolts and reinstalled using the red Locktite. Ran out of time to today but
> will work on it again tomorrow. Will remove the carb again and close the
> secondary to see if this will bring the idle down.

WHOA, NELLY!!

Dan,

What do you mean "Will remove the carb again and close the
secondary to see if this will bring the idle down. "??????

I know you have to remove it for the stud leaks, but what's this 'close the
secondary' mean?
If this carb is set up correctly, the secondaries are ALWAYS shut, until the 
flow
thru the primaries REQUIRE additional help, then the secondaries are 
automatically

opened by the vacuum diaphragm. The secondaries should not be adjusted by 
anything
you do




> When I do this I tend to
> have a problem getting the car to run smoothly at idle.

You still haven't double checked float level with fuel pump on (electric SU) and
inspection
ports open.  This is when you actually adjust the fuel level by holding the
screwhead still and
turning the nut.


> BTW, I found that if
> I open the throttle to WOT I can use a 1/4" open end ignition wrench to
> adjust the choke.

Thanks, Never tried that.

> Everything so far is by the book. Even took the carb apart
> to check the gasket. Used the new gasket on re-assembly and it made no
> difference. The throttle body I"m using is the 112-20. According to Holley
> and their book, the only difference is the throttle bore diameter. The carb
> is 1 1/2" and the throttle plate is 1 9/16". According to Holley and
> yourself this shouldn't matter.

It doesn't.

> Any ideas? Open to suggestions. If anyone on
> the list has any ideas, they sure would be appreciated. Thanks.
> Dan Eiland
> B382002652LRXFE

The secondaries should be fully shut with the carb just sitting on the bench
(with those stove bolt legs).  Opening the throttle fully should have no effect
on the secondaries.  If this is NOT so, check back, as something is wrong.



--
Steve Laifman         < Find out what is most     >
B9472289              < important in your life    >
                      < and don't let it get away!>

_/_/_/_/_/_/_/
     _/                 _/_/_/       _/_/_/       _/
    _/        _/      _/     _/     _/    _/     _/_/_/_/
   _/        _/       _/    _/      _/  _/      _/
  _/_/_/_/_/__/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
                            _/
                     _/_/_/



<Prev in Thread] Current Thread [Next in Thread>
  • Re: carb adjustments, Steve Laifman <=