[quicksilver97ta]

I am going to finally start playing with a Qjet and this is the candidate. From what I’ve read it’s the 800 cfm variety and has the more desirable APT. I found a thread here that stated it came from a 78 350 Pontiac.

1. This will be going on my 68 bird and which has the ram air pans in place. Is there any issue with this late model base plate linkage or the carb itself interfering with the lower pan? Spring return provision ok?

2. This carb appears to have the hot air tube choke design but I plan to use a 69 intake which is a divorced choke deal. Can this carb be changed over to a divorced choke? I read in Cliffs book that it can be converted to an electric choke. Perhaps this is more desireable? I might want to cut off the heat crossover completely as I did with my T2 and I really like the clean look. Also, how many choke pull offs do you need with a divorced or electric choke? This carb currently has two. Again just wanting a Spartan clean look to the whole set up.

3. It looks like this carb does have the provision to mount a throttle stop solenoid which I want to use for my A/C as I already have one in place on my Holley. The solenoid bracket is missing on this Qjet but I have a bracket from a Dualjet that I hope will work?

I’ve never owned or worked on a Qjet. I plan to have a local reputable carb shop do the initial cleaning and basic rebuild including bushing the throttle shaft and addressing the well plugs. Hopefully I can decide what choke I want and they can fix me up with that too. Beyond that I would probably prefer to do more of the modifications listed in Cliffs book myself later. I would like to ask this shop to set me up with a particular combo to start with though. My engine is an 428 (.030), true 10.5:1, iron d-port closed chamber, 240/242 HFT, 2800 converter. Makes about 11” vacuum with the Holley and T2 but it was around 12+” with a 66 tripower.

In Cliffs book recipe # 2 calls for :

.072 to .074 main jets
Tapered primary metering rod at least .029 less than the main jet at the widest point
Secondary hanger G or higher
Secondary metering rods .036 to .048

This is just a starting point as I am a total noob to the Qjet. I appreciate any advise and if there is anything glaring about this as a starting point I certainly appreciate someone pointing that out!

[David Jones]

Do you need a choke?

Will this carb shop also be able to address the idle tube cleaning and adjustments in size as needed?

Do it yourself............

[android 211]

You can convert the hot air choke to electric. The '78 Rochester has a vent on the lid which will hit the bottom of the air cleaner unless you drill a hole in the bottom of the pan to allow it to poke through.

[Cliff R]

17058241 is a 1978 Buick, not a Pontiac. Still a fine candidate for a really nice high performance carburetor. The only trump card is the "goofy" linkage to hook up the throttle cable. I remove the hooked portion on most of those with an angle grinder for non-Buick applications.

Save the time, headaches and aggravation and do the build yourself. If you have my book your are already most of the way there. Any local "builder" is just going to complicate the process. Most wouldn't know what an idle tube is, or idle bypass air, airbleeds, or much about anything else, at least not enought to get you pointed in the right direction.

The key to success is knowledge and good parts. We sell everything required for that part number, and can supply the correct tuning parts, rebuild parts, electric choke, and throttle bushing install kit, etc, so it's basically "plug and play"......Cliff

[quicksilver97ta]

I will ask them specifically about the cleaning David. As far as resizing I might want to do that on my own. If that is something I need to do before I run the carb then I’ll make sure it happens. The recipe calls for .037 to .038 but I don’t know what it is in stock form, so, I don’t know how much of a priority it is. That shop seemed to do a good job on Txbobcats carb as far as cleaning and proper operation but I am unaware if they modified anything.
I think I need a choke. It gets pretty cold here in North Texas sometimes and I had a choke on my tripower which worked great. The Holley does not have one and I have to hold a fast idle at start up in cold weather.
Android, thanks for the heads up on the vent tube.

Here is Bob’s carb done at that shop: I think its OK, and, it will just be a starting point for me which I need. I will work on the other mods in the book like a rolling restoration.

[MG12692]

quicksilver97ta,

This is a little off topic and apologize for it, however would you mind posting a few pics of your ram air pans that are mounted on the hood and engine? I have a friend that purchased the ram air set of from the Parts Place and for the price that he paid it fits terribly. Would like to peek at yours to compare.
Thanks!

[cutlas]

I would just buy the kit from Cliff.
That is what I did and He is very helpful.
I was able to email Cliff and get responses about what goes where when I was confused.
Rebuilding my carb with his kit and help was a good experience.

[quicksilver97ta]

OK, just got off the phone with Cliff and parts are on the way. I was really hoping to save some time and get some of the grunt work of cleaning and bushing install farmed out while I prep the intake but you guys encouraged me well enough. We’ll see how it goes. Cliff was very helpful on the phone and I jotted down the basic “do’s” for this particular carb rebuild and my application, thanks Cliff, that will make it a lot more straight forward than digesting all the info in the book at once. I’m very detail oriented and I would, and still eventually will.
MG I researched at length what repop pans to get. It was pretty simple at the end though, Warpath Restoration. At least when I bought mine they were the only ones making the hood pan in metal and they are 100% correct in fit and appearance.

[David Jones]

Your time and money ahead doing it yourself. Now you KNOW it will be done correctly. I've run a 79 Buick carb on mine now for years. Bushing install will only take a few minutes.

[Cliff R]

Many thanks. Since you started with a nice unit, it will be a good end result. For all practical purposes it's the same carb I use on my own engine, just slighty different set-up for air bleeds and a few other items. I sent the parts required to dial it in without any guesswork, don't hesitate to call or email if you get into trouble.....Cliff

Below are a few pics of a rare original 1973 Super Duty 4 speed carb we finished up a few days ago:

[chitownTA]

+1 for rebuilding it yourself.

I had mine "rebuilt" by the most reputable shop around, been around for 50 years. They even had a carb flow machine. Still never could get it to idle right or get a bog out bringing it back to them 5 times.

Carb sat on the shelf for 3 years while I messed around with Holley type carbs that had their own issues(rotting pot metal fuel bowls).

Finally bought cliffs book and a full rebuild kit from him after my neighbor kept telling me to toss the qjet in the garbage and there was nothing wrong with the Holley carb.

Pulled the carb apart and nothing was modified for the idle circuit. All the carb shop did was dip it and screw around with jets.

New idle tubes and drilling the right size holes had the engine idling great.

For pulling the idle tubes I found the shiny interior trim screws to work the best. Just grind the tip off and a few turns in will pull even the badly stuck tubes. Just go slow tapping the tube in the middle out with a small punch. I use the handle of a screwdriver to gently tap the punch until it looks like I can get about 3 threads in with the screw.

And just take your time. Read the book a few times especially chapter 2. You need to make sure you know which orifices are where before you modify them.

[unruhjonny]

I'm glad Cliff chimed in here...

I read the 'preview' of this thread where you suggested that this was a '78 Pontiac 350 carburetor, and felt the need to chime in on two inherent flaws with that statement;

1) The Pontiac 350 was built, and installed in 1968-1977 Pontiacs;
>to the best of my knowledge no 1978 Pontiac 350's were built.
>>I believe the only Pontiac engines produced in 1978 were the new short deck engines, and the 400 (in it's final year of production btw)
>>I believe the only 350 powered Pontiac's were "corporate" as in they either had Chevy, or Buick engines.

2) To the best of my recollection the numbers allotted for Pontiac's carbs were;
'26- & '27-
additionally, (I am not familiar with OHC carbs) I am not aware of any Pontiac carbs ending in "1" ~ I have seen buick & chevy carbs that way though...
262, 263, 264, 265, 266, 267, 268, 270, 273, 274 are the more common Pontiac Carb suffix's

-------------

For anyone's future use;

To decode a Rochester;

OEM carb numbers break down into three parts - before and after the model year;

17058241

1a) "1705" (vs 702 / 704 / 1708)
> 1b) "70" is one float bowl depth, "170" is a different float bowl depth
>>1c) "702" are for 1969 & earlier; "704" are for 1970-1974/5; 1705 are 1976(?) through 1980; 1708 are 1980 through 1987

2a) "8" model year final digit;
>2b) if this was a 7028 this would be a 1968

3) "241" this is the application number; to the best of my knowledge most Rochesters ending in an uneven number were intended for manual transmission applications.

I hope my post is of use to someone... at some point

[David Jones]

I use a fine thread drywall screw with the sharp end ground off for pulling idle tubes. Screw it in a bit, lay a piece of wood across the carb body and use a pair of pliers to rotate them out.

Cliff's book takes a lot of the unknown out of working on a qjet.

[tjdjr]

ya the drywall screw and a little heat worked great on them tubes !

[quicksilver97ta]

The carb is now disassembled including the idle tubes. The idle tubes did require some propane heat as the first try without it was unsuccessful. With the heat they came out really easy. I’m going to take my time cleaning. I have a gallon of Berrymans that did appear to remove or at least lighten some of the plating on my Holley so, I will be extra conservative on the soak time for the Q-jet. After that it will be time to remove all the butterflies in the air horn and base plate. I am aware they are staked.

[quicksilver97ta]

Update:

I disassembled every component of the carb including the butterflys but there was corrosion inside the main body that the chemtool was just not getting, not even with a variety of modified cleaning brushes I was using. It began to start stripping the plating off the rest of the carb, the plating would rub off with my fingers but the corrosion remained. It was not really deep pitting just very stubborn. At that point I took it to a carb shop to have it bead blasted and powder coated. However, he would not do this unless he rebuilt the carb. Fine, whatever. With a 2.5 day turn around it was well worth it. I spent the time modifying two throttle cable brackets into one and fabbing a throttle position sensor bracket and linkage. After picking up the carb I immediately opened it back up and performed all the modifications per Cliffs instructions and a few more in his book I thought were good as well as my own consisting of blocking all the un-needed and unsightly vacuum ports. Fingers crossed, I hope to have it and the repop HO intake on the car tomorrow. PSN is next weekend and I’ll take a week just to detail the car.

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