Anyone got some AU metering rods to lend or sell me? My only goof was ordering a carb for 80s stuff then going to a TA intake, as National did A great job but once I changed intakes I need to tune some. No EGR and junk anymore. Larry said dump the CZ rods and try some AUs Maybe someone has some I can try and or buy. Or where do ya find such parts? Are there any kits with a selection. Search on ebay and came up empty.
We can machine any metering rod that you would like. Provide the tip diameter and length that you would require, and we'll cut/replate them from larger cores.......Cliff
I don't have any AU's, but I have a few sets of DA's. They would be a very close match. They would have medium tips as opposed to long tips. If you're interested, give me an address and I'll send you a set to try out. Dan:beer
Thanks all I send out PMs. Ill gladly return them if they don't work out for me, or pay if they do. At this point I don't want to have parts made that I don't know if it will help.
The problem with experimenting with different metering rods is predicting IF they will change the A/F ratio at WOT consistantly based on the tip diameter? Keep in mind that secondary metering rods will have different sized tapered section/tip length and the transition between the upper section and the tip is not the same between different part numbers. We have changed metering rods right on the dyno .010" smaller and the next pull showed leaner than the previous one. We've actually observed richer fuel curves with .040" metering rods than .030" metering rods simply because of different tip length, and upper section diameter/shape/transition to the tip. Did you ever notice how some folks will report seeing significant gains simply by changing the hanger height in conjunction with a metering rod change, even if the initial change between the metering rods was only a few thousanths of an inch in tip diameter? If you have a consistant running car and a complete set of machined metering rods from the same cores, the change in ET and MPH should be very minimal one direction or the other with metering rod changes. If you see dramatic improvments going from, for example a DA rod at .044" to an AX rod around .040", then the rod shape and tip length accounted for most of the change, not the tip diameter all by itsself. The other problem we see is that metering rod tuning is greatly effected by how good the fuel delivery system is at keeping the carburetor full on hard runs. If the fuel level is not the same from one run to the next, tuning with secondary metering rods is next to impossible. Most racers have a decent assortment of metering rods. I would suggest that they also arm themselves with an assortment of hangers as well, and test each metering rod installed at several different heights when making comparisons. Another interesting item that we see is that folks with marginal fuel delivery systems end up with HUGE jetting and tiny tipped metering rods, at least in comparison to our Stock and Super Stock customers, who typically order much larger tipped metering rods, clear up to .065" and even larger on occassion. This happens for two reasons, BSFC and engine volumetric efficiency is greater, and they usually feed their engines with a garden hose (8AN or 10AN lines), compared to most street and street/strip cars with small fuel lines and HP mechanical pumps, fed by stock lines pulling thru a stock sump, etc.......Cliff
My problem is at the top of a shift at WOT, sure we all know what its like when you let the tranny shift, Soon as it starts to reach that peek area before a shift it noses over on power, which almost make the shift hang a sec longer, then it will shift and take back off like normal. Super annoying as it usually onle happens when I got to pass some and could make the differnce between passing quickly or freaking out someone coming inthe other direction as Im taking to long. New single line FP, carb is new, but it was orderd for 80s with EGR n crap, then I went to TA intake with no EGR n crap.
not to jump in the middle,but where and how do i find out about the metering rods? had a lean issue last year before i parked car. changed regulator, as it has a holley blue on it, it was screwy. now im got a true 8 pounds of pressure, i want to richen up secondaries a bit. NOS, 100 shot. also want to mess with vac on secondaries a little, maybe open sooner? dunno
My problem is at the top of a shift at WOT, This is a common problem, and in most cases is fuel delivery related. We see debates all the time over on the PY Website concerning fuel delivery systems. There is ALWAYS someone who comes on and reports 10 second runs with a "stock" fuel system who didn't even remove the "sock" from the pick-up in the tank. This is typically followed by 30-40 guys who can't get out of the 13's trying to do the same thing. If the car is being drag raced, with good tires/traction, consider this. When you are pinned against the seat, ALL of the fuel in the tank is pinned up against the bumper. Don't expect to be able to "pull" it through stock lines, and/or a stock located pick-up and keep the carb (any carb) full on hard runs. Also, do NOT expect to be able to pull thru 14' or so of 3/8" (inside diameter 5/16") fuel lines to a mechanical pump of any manufacture or output rating, and always keep the carburetor full on hard runs. Before any effective carburetor tuning can be accomplished, we must make sure the fuel delivery system is adequate for the power and ET/MPH the vehicle is capable of. My approach is to install a fuel system capable of 10 second runs on a 12 second car, not the other way around. What some folks can get away with, others can not. On my own car, I drag raced and street drove it for years, running 12.40 to 12.60's, with a best ever 12.37 @ 109mph. This was back in 2001 when the engine dyno'd 455.4 hp and was basically a 10 to 1 SCR 468cid with unported iron heads. Over one winter, I sumped the tank, and moved the Comp 140 pump behind the tank, and installed 8AN lines/fittings everyplace. The very first runs the next season were 12.11, 12.12 and 12.05 at 112mph, NO OTHER CHANGES! I had always noticed the power falling off a bit up around 5000-5200rpm's, but just figured it was the iron heads and factory iron intake combined with a RAIV camshaft. After the fuel system upgrade, the engine pulled right to the rev limiter (5800rpm's) so fast I could barely move the shifter quick enough (12.11 and 12.12 runs). After the upgrade, I strarted shifting right at 5500rpm's, and the car was deadly consistant. A few more upgrades and we were running 11.60-11.80's at 115-116mph. This resulted in us winning the Stock Class at the Pontiac Nationals several times, along with a half dozen other races that we entered. Here's a link to one of our passes, the "King of the Hill" race at the Tri Power Nat's in 2006. I had already won the "Stock" class, and the winners of the other classes to get to the final round. This is our daily driven car, 455 cid, using a 1977 Q-jet, iron intake, 3.42 gears, and 10" Continental converter, race weight is 3760lbs.....Cliff http://www.youtube.com/watch?v=t9eWgLd0q-U
how about this, have had it planned for some time though. Ill get an electric pusher pump installed in the rear, it will run off an oil 7psi switch so it don't keep running in a wreck. That should feed the FP and carb better under high demand so it not trying to suck fuel from 14ft away.. Ill still try some different rods for kick and see what I get. Then return, pay for or pass the rods on to another needy Buick member???
In the inbetween time since my first post I did play some, I pulled off n plugged the vacuum line for the vac brake for the secondaries. Checked spring tension. And that did make a big difference from a few days ago but its still there a tiny bit. Though I will go the next step and install a pusher electric pump in the rear run off a 7psi oil switch for safety. That should keep the on the block pump from having to suck fuel at WOT from 15' away. And scouts honor, this has never happened before. But once that vac brake was off and while out testing, honest to god. On one of my test runs my left corner lifted really high on a 1-2 shift. I doubt it got off the ground but man never in its life has it went up like that. Way beyond normal lift or rock on a shift. [need to get that posi installed] One of them rare moments you wish someone was there.
