adjusta-jet carb metering plates

[grumpyvette]

If your into getting the car tuned correctly, as most of us are, you can learn to read plugs and use an INFRARED heat sensor gun and a vacuum gauge, and timing light, like most of us old school guys learned with,and eventually gain the required tuning skills to select the correct jets, power valves and carburetor accelerator pump cams or you could install adjustable jetting plates that allow you to quickly adjust your jetting with a screw driver as you tune the car, and bypass some of the learning curve.

used in conjunction with a fuel air ratio sensor

http://www.innovatemotorsports.com/products/lm2.php

READ THESE LINKS AND SUB LINKS, IT MAY TAKE YOU SOME EFFORT BUT ITS TIME VERY WELL SPENT
http://www.knfilters.com/airfuelmonitors.htm

http://www.carcraft.com/techarticles/11 ... index.html

search.php?st=0&sk=t&sd=d&keywords=%2Binfrared++%2Btuning++&start=20

viewtopic.php?f=44&t=579&p=743&hilit=+infrared+tuning#p743

viewtopic.php?f=70&t=202

viewtopic.php?f=55&t=109

viewtopic.php?f=55&t=1442

http://www.chevyhiperformance.com/tech/ ... index.html

viewtopic.php?f=55&t=5229&p=15353#p15353


http://www.summitracing.com/parts/PHP-15001/

http://www.summitracing.com/search/Bran ... toview=SKU

http://www.percyshp.com/adjustajet.html

holley does sell quick jet access/change fuel bowls
KITS 34-24, 34-25, 34-26, 34-27, 34-508, 34-509, 34-510, & 34-511

http://www.holley.com/data/Products/Tec ... 9R9814.pdf
http://www.summitracing.com/parts/HLY-34-24/?rtype=10

http://www.jegs.com/p/Holley/Holley-Qui ... db0de2603c

http://www.summitracing.com/parts/SUM-210230/?rtype=10

heres a neat little option for the HOLLEY carbs, its not really In expensive, (CHEAP) but it does allow you to effectively change the fuel flow rates far faster and easier than you could changing JETS, its basically a needle & seat valve that adjusts like the float levels do on a Holley carb, it comes with detailed instructions , and if you use a fuel ratio meter or an IR temp gun and read spark plugs it will allow you to adjust the fuel air ratio far faster and easier than jet changes will

ignition timing thats a bit to retarded will tend to make the plugs run cold and foul, setting your float levels and making 100% sure the linkage functions correctly is mandatory, before you start chasing problems

http://www.barrygrant.com/bgfuel/default.aspx?page=83

http://www.stockcarracing.com/techartic ... index.html

http://www.holley.com/data/TechService/ ... uretor.pdf

unscrew the site plugs and adjust the floats until the fuel level just prevents fuel flow from the site holes at idle, youll need a flat blade screw driver and a 5/8" wrench


QUESTION How do I adjust the fuel level on my carburetor?
ANSWER Setting the fuel level should be the first thing you do before attempting to make any further adjustments.The float level should put the fuel level just below the bottom of sight plug hole. You will make the adjustment with the vehicle on a level surface and the engine idling. You will first remove the sight plug, then to make your adjustment you will need to loosen the lock screw on the needle and seat. This will allow you to turn the adjusting nut to raise or lower the float level. Each hex flat on the nut will change the float level approximately 1/32". When you have the fuel level just below sight plug hole you will then tighten the lock screw and reinstall the sight hole plug. Make sure you have a shop towel handy in case you have any fuel leaks from the Sight plug or needle and seat adjusting nut.

if the fuel level won,t adjust, it
sounds like a needle valve needs replacement, or a carb floats defective

SIMILAR TO THIS

http://www.summitracing.com/parts/HLY-6-513/

http://www.summitracing.com/parts/HLY-6-519-2/

http://www.summitracing.com/parts/HLY-116-10/

viewtopic.php?f=55&t=109&p=136#p136

thoughts guys?

 

[grumpyvette]

http://www.hotrod.com/techarticles/spee ... index.html

hot rod carburetor shop list
http://www.performancemarket.com/carbs.htm

Quick-Change Jets

New Speed Blocks Make Jet Changes Too Easy
By Jeff Smith
Photography: Jeff Smith
We hot rodders are a lazy lot. We’re always looking for ways to make things easier. In the movie Two Lane Blacktop, the late Beach Boys drummer Dennis Wilson played a mechanic who spent the entire movie changing jets in the twin Holley carburetors of a big-block–powered ’55 Chevy. If he had had a set of Brad Urban’s Carburetor Shop Speed Blocks, he might have had more time to go after the girl in the movie.
For the rest of us, Holley carburetor jet changes are a fact of life. You drain the fuel from the float bowl (spilling fuel all over your intake manifold), remove the bowl, change the jets, replace the bowl and then replay the routine for the secondary side. If you’re exceptionally gifted, the gaskets tear and you spend half an hour scraping gaskets off the bowl and the metering block. If you haven’t been through this drill a few dozen times, don’t count yourself as a true hot rodder.
Brad Urban has probably changed more carburetor jets than the rest of us combined. After a few thousand repeats of this brain-numbing procedure, he began to think there had to be a better way. Enlisting the help of compatriot Louie Hammel, the two developed the Speed Block, a fully CNC-machined aluminum metering block that duplicates a standard Holley metering block, but with a high-speed twist.
Instead of mounting the jet in the metering block, Hammel created a brass cartridge that screws in from the top of the block. The bottom of the cartridge holds the jet in place inside the metering block in roughly the same location as the original Holley design. The beauty of this is that the cartridge can be removed from the Speed Block without removing the float bowl. This makes for incredibly quick jet changes.
Now you no longer have to drain the float bowl to make jet changes, which also means no more spilled fuel over a hot intake manifold. This dramatically reduces the risk of fire.
Taking this one step further, it’s possible to change the jets in the carburetor even when the engine is running. Since the idle feed restriction limits the amount of fuel delivered to the idle circuit, there’s no change to idle quality if you remove the jet cartridge from the Speed Block while the engine is running. We’ve tried this on a couple of cars, and it works just as Urban claims. Now that we’ve played with the Speed Blocks, we’re definitely spoiled. We’ll certainly never do another dyno test without them. Over the years, Holley has created several different metering blocks for the 2300 two-bbl, 4150 four-bbl, 4160 four-bbl and Dominator Holley carburetors. Speed Blocks are available for all these applications, including alcohol carbs. You can even use a primary metering Speed Block on the secondary side of any Holley for four-hole idle control with a modification to the throttle plates that Brad Urban’s Carburetor Shop can perform for you. The Speed Blocks retail for slightly less than $100 each. For drag racers, circle burners or street enthusiasts who are looking for ways to make their lives simpler, the new Speed Blocks are the quick-change ticket for any Holley carburetor.

SOURCES
Brad Urban’s Carburetor Shop
8460 Red Oak St.
Rancho Cucamonga, CA 91730
909/947-9722



The Speed Block is a direct replacement for the original Holley metering block. With the Speed Block, the jets are easily replaced without removing the float bowl. In fact, the jets can be changed, as shown here, without even shutting down the engine. Note the jet positioned at the bottom of the cartridge.

This tight view shows the cartridge removed from the Speed Block. The three holes drilled into the cartridge are the same diameter as the main well-holes in a standard Holley metering block. To make jet changes even quicker, have spare cartridges fitted with the proper jets ready to replace.

Fitted with twin Speed Blocks, this 3310 Holley is ready for some ultraquick jet changes. In a quickie test, we were able to change jets in all four corners of this Holley in less than a minute.

One option for the Speed Block is the knurled idle-mixture screw called the Speed Screw. This allows you to adjust the idle mixture without a screwdriver. The tapered portion of the Speed Screw is a duplicate of the stock Holley idle-mixture screw.

This view of the Speed Block (foreground) compared to the standard Holley metering block (background) illustrates that the stock passages for the idle circuit, the main circuit, the power valve and the air bleeds are all duplicated in the Speed Block. Changing to Speed Blocks is a simple remove-and-replace operation.
these come in handy

http://www.chevyhiperformance.com/tech/ ... index.html

http://store.summitracing.com/partdetai ... toview=sku

http://store.summitracing.com/partdetai ... toview=sku
http://store.summitracing.com/partdetai ... toview=sku

 

[grumpyvette]

http://www.pontiacengines.com/RapidJet.htm

 

[mathd]

This winter i am going to be buying/installing the LM-2 on my car, no carb tuning has been done yet.
I am thinking alot about the adjustable metering block(so no need to disassemble for main jet change) for my holley double pumper, but i question about the reliability?.

Did someone has tryed them/problems to report?. Or should i stick with main jet changes?

 

[grumpyvette]

Ive used several carbs with the adjustable jets, its a great feature with zero down side as far as I'M concerned, well other than COST of the parts required, I probably would never have bothered trying them as cost was a major factor but Ive got a couple carbs over the years in trade with the adjustable jets already installed.
changing jets is always time consuming, a bit messy with minor fuel spilled and even re-useable gaskets eventually get damaged and leak, the adjustable jets solve most of that and make track adjustments and tuning far easier, you can spend far more time learning how to read spark plugs and enjoying the car rather than cleaning up minor fuel spills and making runs to purchase new gaskets or looking for dropped fuel bowl bolts, jets and gaskets, under the car.

 

[legerwn]

Are the speed blocks still available, Rapidjet

I don't find them doing a search,

The Percy's adjust-a-jet is interesting, it looks as if only one needle is used to adjust both primary's

Neal