cincyDelta

I have a 66 Olds Delta 88 convertible, 425 ci.
The previous owner had replaced the original intake manifold & 2 bbl carb with a "Holly Street Dominator intake" and Qjet 4bbl having a "Manual choke" (I believe manual because there is a **** attached to the dash with a cable running out to the carb) is this Manual?
I want to rebuild/replace the carb due to performance but never having done this would like some input.
First, I looked up the casting number (7026254) for a rebuild kit but with this manual choke I'm not sure about the correct kit to buy.
Also there is a "used" Qjet on ebay with a #7026250. Could I rebuild this and would it be adaptable to my manual choke?
Any recommendations and input is greatly appreciated..

Regards,
CincyDelta

JATA

Yes, most likely you have manual choke...if the cable runs to the carb. Have some one sit in the car, push the gas pedal down a little and pull the **** out (in and out) while you looking at the carb with the air cleaner removed you should see the choke working or moving. What is wrong with the current carb that it requires a rebuild? Is it leaking? Or maybe it is a matter of you not understanding how the manual choke works, and is hard to start and floods out once started?

MDchanic

Slow down there, pardner.

First: Yes, when the choke is controlled manually, it is a manual choke.

Second: You can use a manual choke with any carburetor, but the connections will be different for divorced choke and hot-air choke carbs. Worst case you buy a universal manual choke kit at the auto parts store for $15 and use the parts you need to adapt to a different type carb.

Third: It looks to me as though the Street Dominator has provisions for the hot-air type choke, so, if you get a hot-air choke carburetor, you could go back to that if you preferred.
Also, if you had a hot-air choke carburetor, you could install an electric choke.

Fourth: The 7026254 looks to be a 1966 carb. with divorced choke and a fuel inlet on the side. The divorced choke carb and hot-air choke intake would be the reason why you have a manual choke.

Fifth: This carburetor should be the correct one for your engine (if it is a high-compression engine), so I would recommend keeping it.
The Street Dominator intake, however, is a racing intake that is completely incompatible with your engine if your engine is essentially stock, so changing that would be my first "performance" move.

Sixth: What "performance" problems are you actually having? Why have you decided that rebuilding or replacing the carb will correct them?

Seventh: What else can you tell us about this engine?
Other modifications?
Compression?
Cam?
Heads?

- Eric

cincyDelta

Not many answers from previous owner so I'm not sure what his aim was.
The card itself has visible signs of rust on certain areas.
There is a hesitation when I accelerate.
I tried carb cleaner but when the car sits for a day or 3 before a cruise-in it is hard to start. I have to pump the gas and crank a lot before it starts.
Once it is warmed up it starts quickly.
The throttle side of the card has a small rubber grommet that is loose where the linkage connects and the linkage going back to the firewall wall is not original.
I'm not sure what his thinking was when doing the work but it seems to me he converted to 4bbl and dual exhaust, which is another issue.

MDchanic

Eh. No big deal.


Could be caused by that high-flow intake manifold.
Could also be caused by dozens of other things, including a dried-up accelerator pump skirt or vacuum leaks.


Check your rubber and steel lines from the tank to the fuel pump, including the sender, for pinholes and cracks - a tiny leak will allow air to seep in, and the fuel to run all the way back to the tank, requiring you to crank and crank to pull it back up.
Also, they make fuel filters for the carb inlet with little check valves in them, and one of those might help as well.


Pictures would help - I can't say a thing without seeing what you're talking about.

- Eric

Octania

Not uncommon- PO "enhanced" the car by destroying the carefully engineered package with an incompatible intake, then jerry-rigging the choke back to 1920 tractor standards, and rednecked the throttle linkage [sorry, rednecks, had to pick a group to refer to] with "whatever was handy".

We have had automatic chokes for many decades now, they work pretty well. Easy to install if you have the correct carb.

Got photos?

Some rust on a carb is not unusual, and should not prevent correct operation.
Hesitation on acceleration indicates pulloff not working correctly and/or accelerator pump malfunction. Easy fixes. My bet is that PO removed the pulloff link to the secondaries, 'cause of the manual choke bullshed, not realizing the function of the parts that he removed. Happens all the time.

Empty carb after sitting indicates the plugs at the bottom of the fuel well are leaky. You can fix it with epoxy or press on to a more modern carb, which should also have the plugs sealed during rebuild. All QJets should get this service.

To fix it you probably need to undo most of the PO's magic. If you don't want to use a factory iron intake with a divorced choke, then a moderate aftermarket AL intake which uses Hot Air choke [or electric as you prefer] would be ideal. Then you just need your carb to have the Hot Air type choke. While your carb "can" have the HA choke system fitted to it, it's kind of painful and requires all the pcs off a donor carb including usually the air horn [lid]. Therefore, I recommend:

Less racy intake

Later carb such as 704025x [1970] on up, with Hot Air [or electric as you wish] choke.
Pretty much any such 1970+ carb will work and have the right choke, and you can put any jets you like in it- such as the ones out of your 1966 carb. Carbs numbered "170..." are the next generation, and do not share parts so readily.

You will still have to rig your car's throttle rod to the carb's lever, but it's not hard to do better than a "loose grommet."

JATA

How about this....trying to keep it simple. Sounds like he is not familiar with a manual choke operation. Pump the gas several times and then push the gas pedal a little and hold with foot. Pull the choke handle and verify the carb flap blocks off air flow into the carb. Crank the engine...when it starts, give it a little gas, and slowly push the choke handle back in to a point it runs smooth and you can remove you foot from the gas without stall. Once warmed up...push the choke pedal all the way in and make sure the carb flap is now open. Sounds like you may have the choke engaged all the time or not at all...

If that doesn't help, it could be many other things...carb being one of them along with ignition, vacuum leak, timing...etc

cincyDelta

Ok...lots to consider...I think I will take those pixs as soon as I can and post them for all of you to see..In the meantime I will also try to make as many of those checks you indicated as possible and give you all an update...

Thanks

BILL DEMMER

7026254 is a 330 w/o. a.i.r. application, will be a little bit lean on a 425. 7026xxx won't have the secondaries dampened by the "pull-off", they were dampened by a piston in fuel, linked to the secondary air valves. 7026xxx will likely be a leaker with regard to the secondary well plugs. the possibility of having the old "patty melt" toilet valve on the inlet is also a strong possibility. also a strong possibility, is that the inlet threads are in poor condition, thus requiring a helicoiling. the plug in the fuel inlet will likely require some attention too. the '66 qj's were not the best implementation, '67 was considerably better. rust on parts of the carb. generally isn't a big deal, but it can make linkages stick. also, be careful of stripping out threads in the '66 carbs. the pot metal is of a weaker alloy.


bill

Octania

"7026xxx won't have the secondaries dampened by the "pull-off", they were dampened by a piston in fuel, linked to the secondary air valves. "
===========
DOH
I totally forgot about that "feature" of the 7026xxx carbs. Correct.

I'll still stick with my previous recommendations.
Less Intake
Automatic choke like cars made since the what, 1950's?
Newer carb installed with a bit less hokey pokey.

65B01Delta

I'm local, I can take a look at it for you....

cincyDelta

https://classicoldsmobile.com/forums...incydelta.html

OK...Hope U all can get to 3 pixs in above URL to my gallery I created.
Fuel lines fm tank to carb checked an no leaks in metal or rubber.
Tried operation of manual choke and U are correct in that it is not working correctly because it hardly moves the from flap on carb.
I tried adjusting but did not get to far into it as I have limited experience here.
U can see the rust I was talking about on the carb and U can see its condition.
Let me know what options I might have.
65B01Delta, Thanks for the offer, let me see where the advice takes me and maybe I can then meet U at a location so U can look at this for me.
Thanks to all

Joe

MDchanic

That's not rusty.

It is definitely one of the rare early-generation QJs, which, as others have stated, are not ideal, but that doesn't mean it's no good.
The two problems these carbs had were leaking from the gallery plugs under the float bowls and the odd diaphragm-type float valves leaking and causing fires.
The gallery plugs can be tested once the carb is apart by filling the float bowl with a volatile solvent, like acetone, and seeing if any comes out the plugs. If they leak, they can be replaced and sealed. There are hundreds of write-ups on this in books and on the interwebs.

Most of the original float valves were retrofitted with replacement needle-and-seat setups, but if yours wasn't, it can be.

I agree that it looks like it needs a rebuild.
While I usually recommend a $20 NAPA rebuild kit with a $10 float, in this case, I would recommend spending the $40 plus shipping from Cliff Ruggles or the other guy (forget his name), as they can help you with rebuild and jetting questions, since your carb is for the 330 and you have a 425.

Since you have to get rid of that racing manifold anyway, I would recommend replacing it with an original '65-'69 manifold with the well for the divorced choke, so that you can run the an automatic choke again (and, for the love of Heaven, please don't paint it Chebby Orange!).

Meanwhile, that manual coke is installed all wrong.
The choke rod moves UP and DOWN, NOT FRONT and BACK.
The idiot who painted the manifold Chebby Orange installed the cable pulling front to back.
You need to reroute the cable so that it curves down, then comes out facing upward, and pulls that link down toward the ground when the **** is pulled out.

Of course, you need so many different things here that it would not be unreasonable to replace it all with a bunch of new stuff, though, personally, I would recommend seeing what you can find out there that's cheap and using that as a basis for deciding what direction to go in - for instance I would bet that you could find an original intake manifold from a member here for free or close to it, which would save you several hundred dollars on a fancy aluminum manifold.

Let us know how this goes, and DO take 65B01 up on his offer.

- Eric

cincyDelta

https://classicoldsmobile.com/forums...incydelta.html

Eric,
I added 3 more pixs as I do have the original intake w/ 2bbl carb attached, see above,
but am not sure what it would take $$ to get them usable again..
Please review and give me your input.
65B01Delta, Let know what you think as well pls...
thanks
Joe

MDchanic

Yup, that's it, and, yes, I did confirm that they used the hot air choke on the 2bbl in '66.
WTH is with all the Chebby Orange - must have been in the air there or something.

Here's what I think: A 4bbl carb will definitely give you a bit more power in a high compression 425, and will probably do so (this is a subject of argument) in a low compression engine.
So, which one do you have?
Look at the front of the passenger side head for a number, which will tell you the type of engine that that head was originally installed on, which you hope is this engine.
If none is there, then the heads have been removed (and may have been reinstalled with the thicker aftermarket head gaskets, thus lowering compression), so look at the back of the left head.





- Eric

cincyDelta

Eric,
With all the overspray I am surprised that the carb isn't orange....
Checked engine and found no numbers on the front of the head near the alt. So I found the numbers however, on the drivers side in the rear of that head. They were M781159 L , which according to that sheet indicated Low compression.

I will have to think about maybe getting the original intake cleaned/blasted and then rebuilding the 2bbl...That intake seems ok, heck its cast iron....I checked for cracks
but did not find anything that was odd.
Thanks again for assist...Will keep U advised...

Joe

MDchanic

Yeah, that's a 9:1 motor, so, good, as far as gas is concerned, but bad as far as maximum performance.

Also, if the heads have been off, there'e a good chance that the 0.016" original head gaskets were replaced with 0.047" aftermarket gaskets, which would make the compression closer to 8.5:1, rather than 9:1, so keep that in mind for future build decisions.

- Eric