lars

For a while now, I've been predicting that most of the jets, rods and springs for Q-Jet tuning will soon be discontinued by GM. It has now happened: GM has discontinued all Q-Jet primary metering rods (passenger car applications), almost all of the power piston springs, almost all secondary rods, and the majority of the available jet sizes.

Currently, the following Q-Jet parts are available from GM:

Primary rods: None
Primary jets: 69, 70, 71, 73, 74, 75
Secondary rods: AX, BG, AH, AN
Power piston springs: 7029922, 7037305, 7029529

That's it. No more tuning parts. Parts are now only available from a few aftermarket sources and from junkyards, so parts will be very limited.

I think I'll have another drink.

billla

Lars, any expectation that Edelbrock will pick up the slack here as they've done for other GM stuff?

Bob Onit

I made a pretty good score yesterday... a bunch of primary rods and jets but only one good power piston.

Time to keep an eye out again for anything and everything I can find.

blunblk68

OMG some people may have to use holleys!!!! LOL

lars

I think it's unlikely. Edelbrock discontinued their Q-Jet reproductions about 3 years ago, and I would predict that they will start phasing out replacement parts and jetting components as demand dwindles. Q-Jets will quickly become just as the other carbs before them (like 4-Jet Rochesters and Strombergs) where the only place to get parts is from other old carbs and from a few specialty suppliers who carry only a very limited number of parts. This hobby is going to become more interesting over the next few years as parts begin to disappear...

lars

lars

By the way - The latest situation with available and non-available parts is reflected in the latest revision of my Q-Jet Tuning Paper. The paper correctly shows which parts are still available, and lists sources for some parts not available from GM. For the latest version of the paper, and for any other papers I have available, simply drop me an e-mail request:
V8FastCars@msn.com
Lars

ptroxx

Lars,
OK, So what does this mean to a person like me who wants to send you my Qjet to rebuild?? I want to send it to you in Dec. Should I start searching for things for it now?? I just have a little stumble in the carb on accel...I also want to send you my dist. as well.
So will need anythig special for my 77.


Thanks George

...Roger...

Lars
In my area over the years there have been a bunch of small carb shops that worked on Q-jets.If you would like I can go back through my business card file and make contact with these guys and see if they would like to sell their stock of Q-jet parts.

MikeMc71

This is very interesting. I own and operate a CNC Swiss machine shop here in Tucson, and I am a Vette nut. I don't think there is any round part in a Q-Jet I can't make. The problem is, I would need prints of the parts, and it would be the best to order in quantities.

Tim H

Oh boy I'll make a small bundle on my q-jet and parts stash in a couple of years!!!

Jim Shea

As I mentioned to Lars recently, it seems that in just the last year or so, General Motors has started discontinuing a great number of old service parts. Even though they are able to make very high markups on the parts, their bean counters have obviously determined that because of the low volume for service, they can save money by just dropping these old service parts.

At one time, General Motors made a big effort to continue service on older Corvettes and some specific Cadillac models. They told suppliers like Saginaw Steering Gear that they had to keep their old tooling available to make specific Corvette parts. This edict seems to have gone by the wayside.

Jim

olescarb

We at Ole's carb (olescarb.com) still have or can order any q-jet main jet (from 66 to 82), most of the primary metering rods in the "B" series and the B, G,K, P, V secondary hangers & AU, AX, BG, DP, CJ, DA secondary rods are avalible for order. almost every metering rod spring is still avalible and the metering rod hanger springs (that keep the rod against one side of the jet when installed) are also in stock and avalible for order. we even have the secondary main jet/disc that is pressed into the bowl and last time i checked my supplier still had another 800 of them in stock.

There is no problem for us to get most tuning parts that are needed for most american carbs but we do have to make a minimum buy from the suppliers that are still in the market. I do have quite a collection of cores for those parts that are no longer avalible when i need them for a job that i am doing

Yes, GM is droping a lot of parts but don't worry there is still a lot of us carburetor building/tuning specialty shops that have access to almost any tuning part we may need.

Lars, send me a list of what you need and i will let you know what is avalible and how much it will run.

Henry @ olescarb

Patrick73

Lars,
I understand that the Edelbrock Q-Jet primary rods are the fat .036" power tips and NOT the .026" passenger car rods.

Q: Are the primary rods at Carbs Unlimited (mentioned in your How to Tune a Q-Jet paper) the .026"s or the .036"s?

Specifically, they carry primary rod part no. W130-44, stamped 44B, OEM # 7034844. Is it an .026"? Your tech paper clearly points out that the fatter .036" rods should NOT be used unless the resultant WOT metering area is accounted for in tuning. An easy to overlook fact when tuning/rejetting the Q-jet.

Thanks!

sindy

[QUOTE=lars;1562073178]For a while now, I've been predicting that most of the jets, rods and springs for Q-Jet tuning will soon be discontinued by GM. It has now happened: GM has discontinued all Q-Jet primary metering rods (passenger car applications), almost all of the power piston springs, almost all secondary rods, and the majority of the available jet sizes.

Currently, the following Q-Jet parts are available from GM:

Primary rods: None
Primary jets: 69, 70, 71, 73, 74, 75
Secondary rods: AX, BG, AH, AN
Power piston springs: 7029922, 7037305, 7029529

That's it. No more tuning parts. Parts are now only available from a few aftermarket sources and from junkyards, so parts will be very limited.

I think I'll have another drink. [/QUOT

lars

The fat-tipped Edelbrock rods are the 2nd design rod type (1975+). They cannot be used in pre-75 carbs. There are no .026"-tipped primary rods for 1975+ Q-Jets available from any source.

The rods offered by Carbs unlimited are the pre-75 (early) rods. Fat-tipped rods were not used in the early series.

As Henry points out, the only sources for carb parts will be a few of the specialty parts houses. Those of us who have been in the carb setup business for some time have enough connections to obtain critical parts. The difficulty will be for the hobby/enthusiast who wants to do a little work for himself - parts will be tough to find unless you have the source connections...

bytor

Check this Ebay listing out..
http://cgi.ebay.com/ebaymotors/Quadr...QQcmdZViewItem

Palengke

I have and original '74 L-48 with th original Q-jet. The idle had been a little rough and idle speed erratic ... jumping from 820-980 RPM. I recently overhauled it using a NAPA kit. When I was reassembling it I noticed in the bottom part of the main body, just directly under where the secondary metering rod will be, there are two holes/ports. One port is plugged with an o-ringed alminum plug. The odd thing is that only one hole is plugged and not the other one. I reassembled it anyways and when I fired it up I still have the same idle quality. Adjusting the idle mixture was even more odd. The driver side screw does not respond t all. I had it turned all the way in and the RPM did not change. The other side responded and I got that set. I just opened the other non-reponding mixture screw 3 turns out and went with it. What could be wrong with my carb? The float was aslo replaced with a brass float and adjusted as per you paper. Help please.

BigBlockk

If the secondary well plugs are not there you will need to take it apart and fix it before you can tune the carburetor.

BigBlockk

Later.....