xpndbl3

iTrader: (5)

Well little update on the blue beast. Yanked the carb back apart to start playing with all the adjustable bleeds it has in the metering blocks and air bleeds. Went down the idle bleeds so I could turn the mixture screws out more than 1/4 turn, that helped clean up the idle a/f ratio and make the screws less sensitive to adjustments. Then pulled out the power valve channel restrictors and put larger ones in, this will allow me to lean out the primaries for better mpg and still have the same WOT a/f ratio.


Old setup:
1000rpm in gear, 13.8-14.0 at idle
13.4 WOT
12.1 at cruise

New setup
950 in gear(still too high but slowly dialing it in)
upper 14s at idle
12.8 WOT
13.0 at cruise


After getting the cruise into the 14s as the next step and then tossing a larger PVCR in there again I think it'll really be a nice driving and performing car keeping the WOT in the 12.8-13.0 range along with the better fuel economy out of the primaries alone. Took the car to a car show last night and put 30 miles on her, while getting wideband readings the whole time and screwing with the carb while at the car show. Can't believe how many guys were shocked to see a LS motor under the hood, then all the carb comments as well

five7kid

iTrader: (14)

I assume your idle restrictors are screw-in as well. Did you consider changing them instead of the idle air bleeds? Did you change both primary and secondary? (I assume you have secondary idle mixture adjustment)

With a wideband, you can tweak all sorts of things in those carbs. Have fun!

xpndbl3

iTrader: (5)

I was told the idle feed restrictors are in control of the fuel metering during the transfer slot area and the idle air bleeds were to allow me to open the mixture screws more. Now if I end up being in the transfer slot area when I'm running rich at a cruise then I'd need to mess with them. This is a 4 corner idle carb, after messing with the primary jetting, I'll see if that does what I want or I suppose next step will be the idle feed adjustments in the carb on the primary side only from what I've read.

five7kid

iTrader: (14)

Most of my experience comes from converting from E85, where you need to increase fuel volume. I first tried idle air bleeds (had a Proform main body with stock Holley metering blocks), had a bear of a time getting it to idle. I finally got E85 metering blocks, which increase the idle feed restrictor size (and change the emulsion bleeds - E85 evaporates differently than gasoline), and it finally idled well (with the original air bleeds).

Well, at least you have the wideband to follow what the changes do to you. It'll be interesting to see what gets it where you want it to be.