krochus

iTrader: (1)

670 CFM vac secondary street avenger on a cammed aluminum 5.3 in a light car

I can tell my transition a/f ratios are jacked without the wideband gauge on its way in the mail.

So knowing that I'll be working on these circuits do you guys think investing in a QFT or Proform metering block from the get go would be worthwhile?

Go ahead and enlighten me on the advantages of these over stock, I've been researching a fair bit but details even from the manufacturer are sparse at best

3pedals

iTrader: (3)

Put the wideband on first.

Pop N Wood

iTrader: (1)

If all you are after is tunability then it is massively cheaper to drill out the stock metering block and make your own restrictors. You've obviously priced out the metering block, but have you looked what a set of screw in restrictors cost? You can get a bag of blanks for just a few bucks.

Besides, you might need to change an air bleed. So unless you want to upgrade the main body you might as well invest in a set of drill bits and bottom taps sooner rather than later.

krochus

iTrader: (1)

Interesting.

Do you have any good write ups or links to share on this?

I have a full machine shop at my disposal so potentially modifying my stock block is entirely possible

krochus

iTrader: (1)

I won't do anything till then as it'd be largely speculation. But it doesn't take anything fancier than my ear and foot to notice how the engine leans up around 2700 cruising along and starts to smooth out and run right.

3pedals

iTrader: (3)

I know. But sometimes it is tough to tell wether the problem is rich or or lean

krochus

iTrader: (1)

True

But WHEN the issue is is going to involve metering block work one way or another.

That or a q-jet ;-)

Pop N Wood

iTrader: (1)

Won't need a machine shop, I did mine with a Harbor Freight drill press and even that was overkill.

Innovate use to have a user's forum with plenty of good write ups but they deleted it. In this thread below I detailed how I drilled out my Holley. Turned out nice. Hobby stores/ebay have the small numbered drill bits and pin vices. McMaster Carr sells brass set screws and bottom taps.

https://ls1tech.com/forums/carburete...-needed-3.html

speedtigger

iTrader: (16)

The Quick Fuel blocks are very nice and will allow you to make any calibration changes needed.

krochus

iTrader: (1)

Thanks for the replies guys.

I just got back from the first drive with the new wideband gauge. Readily evedent is the fact that for a "street ready" high performance carb the current state of tune is an absolute basket case of going from one extreme to the other as different elements of the fuel metering system comes into play.

It'll go from peachy idling in N @13.5 to lean in gear (15+), pig rich at a very light throttle cruise (11-12) to lean again at highway speeds (15-16) and back to pig rich at WOT (10 or so)

I've got my work cut out for me on this carb, but before I do I'm gonna try something unorthodox

speedtigger

iTrader: (16)

Set your idle mixture with the car in gear. Make sure you block the tires and set the parking brake.