Hey all Im trying to go a little more rich inmy secondary rods I have 2 to choose from DP AND DB. The DP are currently installed does anyone know if the DB would bea better choice? Also I have two rod hangers I and J
Very little difference between what you have there, but go with J hanger and DP rods to go a slight bit richer.
Thanks! Made it my goal to get it going by this summer. I'll give you a hollar as i'm going to need some extra parts
The best way to get a good end result changing metering rods, is to have a couple of sets machined on a lathe from the same cores. This will keep one from having to "juggle" hangers at the same time. It is actually possible to install a smaller tipped metering rods and lean up the fuel curve, as few metering rods are designed with the same upper section taper, tip length, and included angle leading to the tip. We provide the service of machining metering rods for a very reasonable cost. All of our customers running Pure Stock, FAST, Super Stock, etc use sets of machined rods for tuning. Doesn't hurt to do the same thing for our street/strip cars, at least if you want good results with minimum effort......Cliff
Didn't think when going down a size in rods it can make things more lean ? Can you elaborate on that? Also do you have a rod size or two smaller then the DP I have?
Unless you are using metering rods with the exact same tip length, and angle from the tapered section to the tip, the fuel curve may not go the direction that you want. I've seen this right on the dyno when testing engines and swapping metering rods. I can make whatever metering rod that you would want, or a set of them....Cliff
The letter on the secondary rod hanger corresponds to the height of the hole that the rods hang from. It is of little value in the service world, because when the carbs went down the assembly line, a worker would install a gauge into the secondary jets, get a height measurement on the airhorn (can't remember where to) and pick a secondary hanger that would place the secondary rods where the engineers wanted them, depth wise, into the secondary jets. This was one of the last steps on the assembly line, and it's purpose was to take into account manufacturing tolerances.
I would use a middle of the alphabet hanger and tune with the rods. We aren't using 5 gas analyzers to try to meet an emission spec, so keep the hanger the same and experiment with the rods.
As mentioned, IF you want good results from tuning, find a metering rod and hanger that works, then get a set of rods machined to the same basic dimensions as the rod chosen, with different tip sizes. No need to touch the hanger once you find the right one. In most cases, the middle range hangers are the best overall choice, as mentioned. G-L would be a good starting point. Tall hangers, like a "B" for example, typically only work well with really "fat" upper section rods with shorter tips. Without any exceptions, the Q-jet users we help out that own the fastest cars on the planet in their classes tune will full sets of machined metering rods, not picking thru a pile of factory rods with various tip size/length variations, etc........Cliff
Ok cliff understand this is my daily driver so it won't see track time just A beat a ford or import at the light. Here's my combo comp cams 260h, 355, flat tops, 9:1 comp, headers, intake, ported tbi heads... no power braking and the engine still wants more
