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Driveway work shop, ha! I'm a high class guy,
I have a garage!!
Anyway, the Fannyometer seems to read good.
While I do get a chirp from the rear tires going into 2nd, I didn't break them
loose like I thought I should from a dead stop. After a bit more fine
tuning, and a few more shots on the test track, I'll let you know how she's
doing.
Dan Richardson
300L Family Heirloom
----- Original Message -----
Sent: Thursday, October 18, 2007 5:55
PM
Subject: Re: IML: '67 Carter carb flat
spot
Not to over complicate the subject, early AFB carbs have no adjustments
on the secondary air valve. It is a counter-weighted valve. The only way to
change the opening vacuum is to remove the top of the carb, remove the valve
and either grind the counter weight, for quicker response, or add solder to
the weights to slow response(opening). This is something that few
would contend with. The AVS, and new aftermarket AFB have the external
adjustment air valve for the secondaries. This makes fine tuning much easier.
Still the jet size prior to 89 (last of leaded gas) would be lean on todays
gas. To correctly analyze this with electronics, would also require dyno time,
not cheap. I venture to say, you could own two or more new carbs. The jet and
rod kit is $50, the driveway work shop, and the all well know fannyometer, are
a good place to start.Ya'll have a nice day, Dave.
--------------
Original message --------------
From: David Whitney
<hazegreen66@xxxxxxxxx>
Unless you are aware of your A/F ratio you will be fumbling in the
dark. Try to find a performance tuning shop that will read the ratios
and have a bunch of other stuff hooked up to the engine. Your local
Mopar club may be able to point you in the right direction. The
tuners will be able to make the proper jet/rod/spring combo
recommendations. Once you have that basic setup you can fiddle with it
from there. Otherwise any change you make could well send you in the
wrong direction. Ten to one they also find some other little things
that will help you a lot.
From your initial post about having flatness between 1/3 and 2/3
throttle, it sounds like you are in the range where the secondaries should
be opening. So many things are happening at that RPM range that you
need to have your A/F ratio correct before trying to adjust anything
else. You need to be sure that the linkage to the secondaries is
adjusted to spec so they are opening when they should, and then you can
fiddle with the adjustable secondary vacuum flap which governs the smooth
transition from two to four barrels. There is a delay between when the
throttle plate opens and when gas actually starts to be pulled through the
secondary barrels. The stiffer your vacuum flap, the longer the
delay. That should be just a short bog, though, not a flat spot.
I concur that you are likely running lean, which is not a good thing
with today's low octane gas and your high compression engine. When in
doubt, run a little rich.
Happy motoring,
David
'91 K-Imperial
driver 200,000 miles
'66 LeBaron dual air and every option known to man
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