Corellian Corvette

I'm working with Lars to get my Edelbrock 1901 carb into shape.

Lars recommended that I replace my fat secondary "DR" rods with a set of "DA" rods.

I called around and none of the local shops had "DA" rods in stock. I pulled apart my old Q-Jet to see if the correct set was in that car.

The Rod on the left (silver) is the 'DR' rods from my Edelbrock. The rod on the right (gold) is the old rod from my Q-jet with no markings on it.

Can anyone tell me, by looking, what size the Gold Rod is? I measured the tips and they are both slightly smaller than .04". However, the length of the tip on the gold rod is much longer.

Anway, here's the pic. Thoughts?

PRNDL

So they dont have the letters stamped on the rods?? I doubt anyone can ID them by looking at a pic! I have been studying Lars' QJet tuning paper with hopes of going thru the same process as you, ie improving the performance of my Edelbrock #1901. I also am taking apart and studying the old Qjet that was on my 68 bigblock. Lars has put together an amazing document and given us tons of data!! He includes the GM part #s for the secondary metering rods. The DA rods are GM part # 7046010. The original rod for my Qjet is AX. The Partsamerica.com online database recognizes these GM part #s, and the parts show up as AC Delco. I just ordered a few miscelaneous carb parts from them. (I will probably end up sending all these parts along with my dissassembled carb to Lars, but this is all part of my learning process!!) :) MJ

Corellian Corvette

Nope -- no markings at all. All I can say is that the tip diameter is the same as the DR rods, but the tip is twice as long and tapers differently.

MNJack -- can you send me Lars paper?

Thanks!

lars

Corellian -
The brass rods are generic rods used by commercial carb builders. They have no letter stamp in them, and are not original rods. You can measure their tips to see which letter code they correspond to: The "DA" rods have .0443" diameter tips with a medium-long tip. Your generic rods have the long tips on them - notice the difference in the length between your brass ones and the DR rods. The long-tipped rods allow the commercial carb builders to be pretty sloppy on the secondary rod height adjustment, since the rod will go full rich upon the slightest opening of the secondary airvalve. This is not really the best setup for a mild street car, and you should try to find a set of the medium or short-tipped rods and set the secondary rod height up as outlined in my paper. This will give you the best level of performance.

For reference, both the "CY" and the "DA" rods have .0443" tips, medium length.

Corellian Corvette

Lars thanks so much! Since I wasn't getting anywhere locally, I wanted to see if the internals in my old carb were good. Both of these tips are the same (very close to 4, certainly not as low as 4.4) - only difference is lengths of the tips.

The configuration that you suggested to me was this:

- 74 mains
- 44b rods
- DA secondary rods

My old carb had 71 mains with 44b rods. Is that a bad setup?

I will call the GM dealership tomorrow and get the DA rods from them. What is the difference between DA and CY rods?

Again, thanks much.

PRNDL

Lars carb tuning paper and accompanying data can be found at:
http://www.corvettefaq.com

Click on "Engine/Drivetrain" and go down the alphabetical listing to Quadrajet Tuning Paper

It is a lot of information for my brain to absorb :confused: but I am reading and re-reading!!

The original carb (which I do not have) on my 68 L36 was #7028209.

Should I try to setup my new Edelbrock #1901 Qjet carb with the same jets and rods as the original carb? This would be 71, 45, and AX secondary rods?

MJ




[Modified by MNJack, 1:58 AM 2/22/2002]

PRNDL

And also, the DA rods are GM part # 7046010 and GM list price is $12.40
Dpn't let your dealer charge you more than list!!
(Part # supplied by Lars, pricing on gmpartsdirect website :) )

7046010
All
ROD
2
$12.40
$8.68
$6.20



[Modified by MNJack, 2:04 AM 2/22/2002]