adjust - a - jet metering blocks

[GUGS102]

anyone run these? seems an easy way to tune while underway? Do they cross refrence turns for size so whe you have ut dialed, you can put in the corresponding jets and leave it alone?
thoughts...??

[SmokinLowriderSS]

Here is an article on somethign similar I found, "Speed Blocks". These use holley jets.
Magazine test (http://www.hotrod.com/techarticles/s...k_jet_changes/)
I found your exact question on a Chevelle board, but only 1 reply to it, which was positive "Had no trouble, worked well".
From a dealer site, looks liek they should be "referenceable".
The needle is completely adjustable and metering changes are easily accomplished once the embossed calibration markings on the needle are noted and referenced. Each of these markings designate 1/8th of a turn. By referring to a handy metering correlation chart included as part of the kit, one can accurately richen or lean the carburettor's main metering calibration. The carburettor can be tuned even when the engine is running.

[centerhill condor]

I'll demonstrate my ignorance...is it really necessary to do all this rejetting?
I thought that the acceptable ratio was wide enough to accomodate temp and pressure changes.
CC

[cvx18gl]

Just put a set on an Avenger carb,haven't run yet,these were made by Holley,but there are others out there.Block is 1/2 in wide,so you need a wider feed line for a dual bowl carb,there is a chart that shows number of turns out for jet size.Simple to install and I wouldn't go back to jets,even after dialed in,reason I went this route was last year,ran new engine on dyno,jetting was right on,then put in boat,jetting way off due to temp and humidity.Took that carb apart 6 times to jet up,pain in butt and messy.Switching heads and a couple of other things for this year,still going to run on dyno for baseline,but so much easier to dial in for actual use or even temp and humidity change from spring to summer,using EGT to monitor jetting.

[infotraker]

Do you know the cost of the setup ?

[GUGS102]

I've seen them from 75-200 a set. Probally could set the primaries with the secondaries disconnected and reverse to get it dialed in.

[BDMar]

We have run them and they work pretty good. It gives you reference marks so changes are easy. We use them primarily on boats that are used regularly on different altitude lakes like Havasu then 2 weeks later Tahoe.
Jobber cost from Holley is $88.00. It is a little pricey when you do both ends of the carb, but not when you consider having to re-jet 5 or 6 times a summer.