1965F85_scholten

Rebuilding the 330 for the 65 F-85 and am about to get it back from the machine shop to put back together. I am now looking at carburetor recommendations.

Everything is being put back to factory, as much as possible, down to the cams, heads and intake but looking for a little more performance than the original Rochester 4 BBL had. Bolt on would be nice but probably not likely.

My buddy is recommending the Holly Street Avenger 570. I've seen threads on this forum that in general say go with QJet.

Recommendations?

GAOldsman

A good running Q-Jet is hard to beat streetwise. The Holley 570 - 600 cfm is a good choice if originality does not matter as well as the Edlebrock 600 cfm is a good choice. Q-Jet and Edlebrock for the street and Holley for Street/Strip would be my opinion.

oldcutlass

My .02... If you were looking for increased performance, the time for that was during the rebuild process. Your best performance carb is the rochester for the stock setup. Any other carb will require an adapter or a manifold change and the performance increase is negligable.

66luvr

Quadrajet

MDchanic

Why would you "put everything back to factory" and then try to gain more power by avoiding the QuadraJet, which should be able to provide all the power you need for a 330?

I second OldCutlass - If you really wanted more power, there are things you could have done during the rebuild that might have made a different carb. advantageous.
At this point, I doubt you could gain anything by using a different carb., though you could lose driveability or fuel mileage.

- Eric

1965F85_scholten

All fair questions. It was a conscience choice to keep everything stock knowing I am limiting myself on the power. I don't want to skimp on the performance/quality of the carb. The Rochester I had in there was a piece of junk so I figure if I am not doing factory then whatever I put in I may as well go,for better performance, even if its marginal at best.

oldcutlass

Like I said, the best all around performance your going to get out of the stock engine will be with the quadrajet. Most any other carb, with a stock manifold will require a spreadbore to squarebore adapter or a manifold change.

I would concentrate and spend my money on good flowing exaust system, gears, transmission, etc...

joe_padavano

Let's back up. If this 1965 330 has the original intake, it's a square bore intake set up for the 4GC carb. This is the one time I'd advocate an E-brock carb over a Qjet. The E-brock bolts on to the stock intake and will run well right out of the box. 600 CFM is probably all you need if everything else is stock.

Edit: Be aware that the original air cleaner will not fit ANY replacement carb other than another 4GC. The 4GC has a smaller air horn than the 5 1/4" that's now standard on most 4bbls. You'll either need an aftermarket unit or a 1966 base that has the larger opening for the Qjet.

oldcutlass

Crap, my apologies, yes the the 65 was a square bore.

MDchanic

Yup. The OP said it right, and we all ran the wrong way with it.

He's got a 4-Jet (4GC). Only Chebby had the QJ in '65.

... And there are a number of aftermarket carbs which would work better than the original.

- Eric

oldcutlass

With that being said, I'd go with the Edelbrock AVS or the Sreet Avenger. I believe the new Demon carbs have gotten past the bad QC reputation they rightly earned a few years back.

1965F85_scholten

Thanks for all the great information. I really don't want to have to rebuild the 4GC. It's a piece of crap. I'll take a look at the after-market carbs. Perhaps Edelbrock. I'd rather not replace the air cleaner to after market, since the whole point was to keep everything factory as much as possible.

joe_padavano

As I suggested above, if you can get your hands on a 1966-67 air cleaner, or at least the base, that should work for you.

1965F85_scholten

Yeah, looking around. Not finding any yet. Too bad I can't go with an adapter ring. They make them for 4 7/32 inlet to 5 1/8 air cleaner opening. Not the other way around which is what I will need.

jensenracing77

What about going with a newer factory intake (67 maybe) and Q jet that would look closer to original? I have a Q jet from a 330 but not sure if i have an intake with the divorced choke. Just a thought.

Octania

deviating from stock?
Aftermarket pre-EGR AL intake
Grind off the ID's
Paint with the engine
Use QJet properly set up, and the correctish 66-67 air cleaner.

Voila', looks stock.

jag1886

I have a 66-67 air cleaner base 5 1/8 hole 17 3/4 overall diameter. That should be the same as yours. Can't say if it will clear the Ebrock choke but it might.
If you want it give me a few bucks for shipping and I will send it to you. I live in Id. so the shipping wouldn't be much.

olds 307 and 403

Get the new Street Demon. It will fit square and spread bore intakes. It will get better mileage compared to an Edelbrock.

1965F85_scholten

Thanks for the offers. I've worked through my options and won't need a replacement air cleaner base from 66-67. I'll post pics when the project is done - it will be all stock, at least under the hood !!!!!

MudEye

Replacing my q-jet carb... have the 330...best 4 barrel replacement? 1967 cutlass 320 hp.... Thanks...Looking for more performance....

joe_padavano

Define "best". Best price? Best quarter mile time? Best gas mileage?

More to the point, why replace your Qjet? The original carb will be "best" for a stock engine. If you have modified the engine, we need to know what was done to provide useful suggestions.

MudEye

Yes..sorry should have been more specific.. And to the point. I have been having issues with my rochester Q-jet. Was leaking gas into manifold. So I had someone rebuild it. He said it really wasn't in shape to rebuild but he did it anyway( I can't complain cause he did it for free ) Well now the accelerator pump is sticking , it bogs all the time, the 4 barrels aren't engaging. I'm generally a tame driver but do like to pass slower cars with a statement. Instead of a roar I get a bog down with no 4 barrel. I can purchase another rebuild Q-Jet from autozone. Or a new manifold ( say the Elderbrock 7111pk ) Assuming these are new carbs and not rehashed ones like the older Q-jets. I was wanting some extra stomping power and was looking for options from anyone who has the 330 motor. Gas mileage doesn't matter. I have a Toyota for that. Unless their is a mild cam I can use with my current stock manifold and purchase another rebuilt Q-jet .
Just asking you wizards cause I don't know......

ankerclanker

Everyone has an opinion on carbs. I just recently (advice from someone on this forum) purchased and installed a QuickFuel 600 slayer for my 65 330 f85 and it works and responds (in my opinion) better than the Edlebrock that was on the car.

ted

olds 307 and 403

Part store reman Qjets should be avoided, send your original to someone like Everyday Performance. Either the Quickfuel mentioned above or the Street Demon 625, second one will bolt to your manifold but might need a spacer to clear the manifold being a 3 barrel carb.

edzolz

There is nothing wrong with the Rochester 4jet. I had one on a 61 Vette with the 283 bored .060. Fuelie heads and 4:11 gear. Turned 13.08 at 113 mph at Green Valley.

Cutlass Fan

Why would you want to ditch the 4-jet?

MDchanic

As Joe said earlier in the thread, Do you have a QuadraJet or a 4-Jet?

- Eric

joe_padavano

The OP from 2013 had a 65 with a 4GC. The current problem is on a 67 330. That poster resurrected the earlier thread, demostrating once again why that is a bad idea, since it leads to confusion such as this.

I'll also point out that the 66-67 Qjets with the cup-style lower well plugs are the only ones that have a high probability of leaking down into the engine. It is very possible that this is the problem. I suggest finding a Qjet rebuilder who has a clue, as apparently the one who rebuilt this carb the last time did not. Of course, you got exactly what you paid for.

Cutlass Fan

Sorry didn't notice that the original post was 3 yrs old. It's too bad that OPs don't finish off their posts and let us know how things worked out.

MudEye

The reason I had the carb rebuilt in the first place ( yes for free ) was because it was leaking down into the engine. That problem is fixed. The 4 barrels weren't engaging before the rebuild. And still are not. The accelerator pump is sticking now yet was not before. My hopes were only to get a little direction either for sticking with the Q-jet culture , which I have been frustrated. Or moving on to a newer ( I mean new not rebuilt ) carb technology with as good or better performance than what I have. That's all I was asking....I was not aware of a similar thread that was started but will be more aware next time. Thank You

joe_padavano

How do you know that the 4 barrels aren't "engaging"? The secondaries on a Qjet are mechanically operated and open when the throttle is moved. If you are looking at the secondary air valves on TOP of the carb while revving the engine in PARK, they will NOT open. They are designed to only open as needed under load, and there is no load in neutral. There is a wrap spring that controls the rate of air valve opening that must be adjusted properly during a rebuild. There is also a dashpot that controls the rate of opening. The diaphragm in these goes bad over time. Did your free rebuild check these items?

What does "sticking" mean on the accelerator pump? Are you saying that it goes down in the bore then doesn't come back up? Or are you talking about a flat spot in acceleration, which could also be caused by improper adjustment of the secondary air valves?

I'm not trying to be critical here, but without precise information, it is not possible to perform long-distance diagnosis.

MudEye

I should have mentioned that the 4 barrels did not and will not engage under load. That is if " under load " means stomping on the gas petal at any speed from 20 to 65 ( stomping hard ) In the morning when I go to start , the gas pedal feels stuck ( thus the sticking ) putting more pressure then unsticks it . When manually observing this action I see and feel the pump sticking then dropping down with much physical pressure( either by hand or foot
Instead of a clean take off on a harder acceleration it instantly bogs down as if being robbed of gas. After the instant bog down it takes off again. I bought the rebuild kit from carburetors.com and a respectable retired mechanic offered his free services because of his love for classics. Whether he did it correctly or not I am not sure. He did tell me that the carb was worn out and that he replaced everything that came with the kit. Thank you for having patience...

joe_padavano

What you have is a bad bog, and IF it's caused by the carb (there are other possible causes, like timing), then there are really two most likely causes. Either the accelerator pump is not adjusted properly or the secondary air valves are opening too quickly. If the problem is the secondary air valves, that can either be caused by an incorrect air valve wrap adjustment or a bad diaphragm, as I pointed out above. All of these are easy adjustments on the carb (or replacement if the diaphragm is bad). As for the carb being "worn out", well, you're SUPPOSED to use all the parts that come in the rebuild kit. That's kinda why you paid for them.

The basic carb does not "wear out". The biggest wear problem on a QJet is the bushings for the throttle shafts. As they wear, they cause a vacuum leak. Bushing replacement kits are available. The other potential problem is corrosion, which can be caused by ethanol in today's gasoline.

MudEye

I am under suspicion that the accelerator pump is the problem. I may be wrong. When I start my Olds in the morning the pedal is stuck. I push it hard and then it gives...t softens as the day goes... Much respect... and thank you...

joe_padavano

It's unlikely that the pump is causing this problem. Try disconnecting the linkage at the carb and actuating the lever on the carb by hand. If it still is sticky, it's in the carb. If not, it's in the linkage.

MudEye

Disconnected the linkage and by hand the carb pump was still sticking. The kit did come with one so it was either installed improper? or something else?
Thanks

MDchanic

I will just interject that I have never heard of a QuadraJet accelerator pump physically sticking or catching.

It's easy enough to press the accelerator pump plunger down with a screwdriver or similar tool and see whether it is catching or rough, and whether it pumps a smooth stream of fuel from the nozzles.

- Eric

joe_padavano

While I have not seen this problem on a Qjet, I HAVE had it happen to me on a 4GC. It appeared that there was a blockage in one of the internal passageways that fed the pump. Due to the way that passageway was drilled from the outside then plugged, it was not possible to clean it properly. I did succumb and replace the carb with an E-brock...

MudEye

It's definitely stuck in the up position as I removed the linkage and as you said used a screwdriver to firmly push it down until it " popped " and then squirted gas into the carb ( hence the bog down? ) While I didn't notice any burs on the pump shaft ( didn't look on the back side ) I did give them the exact q-jet model # when ordering the kit. Is it possible that these kit pumps are universal to other carbs? ( don't know ) and that the fit is not perfect? or possibly as Joe mentioned that dirt in passageway could not be cleared...( the carb had a gas bath for a night ) but doesn't necessarily clear the fact that it could still be clogged?
I may just try a new pump first before investing in a new carb.....

MDchanic

The carb. has to come apart and the plunger and bore have to be inspected.

The tolerances for the plunger and bore are very forgiving, and I would highly doubt that this is a problem of the wrong part.

- Eric