[61man]

Does anyone know what size jets and metering rods came in 62 SD carbs, also were the front and rear jetted the same?
Thanks,

[61man]

Does anyone know what size jets and metering rods came in 62 SD carbs, also were the front and rear jetted the same?
Thanks,

[carbking]

Which SD carbs (by number)? There are several different.

Jon.

[61man]

Thanks,
The 3433S and the 3435S is what I'm interested in.

[carbking]

Both used 16-92 (0.060 x 0.054) rods, 120-159 (0.089) primary jets, 120-222 (0.070) secondary jets.

These calibrations will not necessarily work in other carburetors even of the same CFM rating due to other pressed-in calibrations (airbleeds, restrictors, etc.).

Jon.

[61man]

I'm using Buick 2982S carbs, do you think that they would work with them? What did the Buick Carbs. come with???? Do you sell jets and rods separately or just in kits???

[carbking]

Pretty well.

Jon.

[61man]

carbking,
Will Edlebrock metering rods and jets work in a carter afb????

[carbking]

I have no idea, as we don't use anything from edelbrock, nor will we; however edelbrock does suggest not using Carter parts in their carbs.

Carter had at least 2 different length metering rods, and different heights on the metering area of the main jets used on various AFB carburetors. Additionally, there are different designs of the flow area of the metering jets. Mixing these designs is NOT a good idea unless Carter suggested a supercession.

By the way, we have several hundred edelbrock rods that were sold to us as Carter. We would sell these to one of you edelbrock lovers at 50 cents each if you take them all.

Jon.

[61man]

Thanks Jon,

I'm not an edlebrock lover, I'm just looking for metering rods and jets for my AFBs, I bought my rebuild kits from you but didn't know that I wanted to try different rods and jets at that time.

[carbking]

No disrespect meant. Give me a call sometime with the rods you are using. The part number (16-nnn) is stamped on the rod. We can give a guess as to how much the correct rods would help you. However would like to get rid of this edelbrock stuff. We can't use it.

The old Carter strip kit number 10-201 comes up occasionally on Ebay. The jets in this kit will fit the Buick carbs. The rods in the kit probably won't help.

Jon.

[61-63]

I don't want to start a ruckus here but Ed Giolma and I went up to Eugene Riotte's place about a month ago and he disassembled a NOS
SD carb, 3435 rear, and it contained;

.088 primary jets

.068 secondary jets

#16-92 metering rods with steps .053 and .059
metering rod spring had 19 coils, was 1.575 long, diameter .018

We got the numbers and measurements on every part. I know you and Ed are friends so you can call him and verify this.

[61man]

Thanks 61-63, I've talked to Ed extensivly about this, Right now I'm just looking for rods and jets, that are right for my 389. He has his running on his 428, but Mine isn't quite right yet. He used 055/061 rods and 089 jets, I'm thinking that is a little rich for my 389, but I'm building a 428 for my car and plan on using the 2-4 set up on it with 716 heads, so our set ups will be fairly close to the same...rods and jets for CARTER AFBs are getting hard to find.....

[carbking]

61-63 no ruckus started; however I suspect your micrometer is slightly off. All of your measurements are close, but all are slightly under the specifications from the Carter blueprints. The part numbers (we agree on the rods) for both rods and jets are stamped on the parts. The numbers and sizes which I stated above are directly from original Carter material.

When I researched the SD carbs some 25 years ago (prior to Federal Mogul's buyout of Carter), I was able to obtain copies of the original prints as well as the TFNs (temporary field notice) covering the SD carburetors for our files.

Before anyone asks, I do not have permission to copy the prints, so I will not. I do have permission, and have duplicated, the TFNs.

Jon.

[61-63]

Jon after my post I reread your message and the
numbers are so close wished I hadn't said anything. I missread your numbers the first time. Neither Ed, Jim, or I (I'm doing a set too) are going to race these cars so what difference does a thousandths make? And we'd have to dial the carb in to fit the engine so original specs are probably irrelevant. And you're probably right on the measurements.

Jim as you know Ed and I couldn't find .068 jets but we special ordered .070s from Jegs.
I got mine but but Ed doesn't have his yet. Mebby I've got the last two sets in existence, heh, heh! How much are they worth to you? I'll trade em' for a pair of '61 buckets.

[61man]

That sounds like a pretty even trade, I'll think about that. He He, I hope to get the buckets in the car this winter, The Carbs do OK but I think that they could do better with some tuning.

Carbking, My existing rods are 16-124, jets are Primary 120-393 and secondary 120-194, right now they are on a 389 with an 068 cam, Do you think changing will help???

[carbking]

61man - its late, but assuming I didn't foul up the math:

Standard 16-92 rod (.060 x .054) dimension converted to area = 2.83E-3 x 2.29E-3

Subtracting these figures from the area of a .089 jet (6.22E-3) results in primary metering area of standard rod and jet of 3.39E-3 high vacuum and 3.93E-3 low vacuum.

Using the 16-124 rod and 120-393 jet.

Rod dimension is .0695 x .0635 or 3.79E-3 x 3.17E-3. Jet diameter is 0.093 or area 6.79E-3

Effective metering then using 16-124 rod with 0.093 jet would be 3.00E-3 high vacuum x 3.62E-3 low vacuum

Comparing the two sets of calibration EXCLUSIVE OF AIRBLEEDS then the standard calibration is 13 percent richer at high vacuum and 8.5 percent richer at low vacuum (WOT).

I think I would throw in a set of 120-395 primary jets if you are going to use the 16-124 rods.

While I dearly love making metering rods on my manual prototyping lathe (about 4 hours per set of 2), and selling them for very high prices , I think the jets would get you close enough (and I can spend 8 hours doing something else)

Your secondary jets are 0.0785 (too large); so it could be argued that the overrich secondary would balance the overlean primary, but I would rather be "right on" on both sides.

Jon.

[carbking]

When doing calibrations on carburetors with metering rods (such as the AFB) remember that the effective metering of the system at any vacuum is the area of the jet minus the area of the segment of the rod in the metering area of the jet at that vacuum.

Most of the AFB rods are 2 step rods (high vacuum and low vacuum). A few are 3 step, a few others are tapered (then the math really gets interesting). The three step rods require an extra circuit in the primary clusters to be effective. The tapered rods are a real pain to cut.

The other variable here is the vacuum piston spring. These springs come in a variety of tensions to tune the position of the metering rod in the jet at various degrees of vacuum. Since a more aggressive camshaft will result in less vacuum, weaker springs must be installed when utilizing a more aggressive camshaft.

One other thing: Carter designed the AFB with the vacuum piston as "sacrificial". That is, the vacuum piston is constructed from a "softer" grade of aluminum than the vacuum well in the main housing so that the vacuum pistons will wear and the housing will not. Vacuum pistons should ALWAYS be replaced as a part of a rebuild on an AFB.

Jon.

[61man]

Jon,
This has been a big help,
Thanks,Tim

[carbking]

Tim - my pleasure.

Tim and 61-63. Jets and rods of ANY calibration (factory or custom) for pre-1974 Carter AFB's are no problem other than cost. This is also true of Q-Jet rods and jets.

Jon.