Let's look at a factory high-performance Quadrajet

These late 70's Pontiac Quadrajets are probably the best of the post-1975 "modified" Qjets. They were originally installed on 77-79 Pontiac 400 engines. Fairly rare.

[@thomasstark5381]

Quadrajets are one of the best carbs ever produced. They powered many GM cars and marine engines too. A truly great design !

[@TylersNeighborhoodGarage]

Couldn't agree more!

[@riveneva1519]

After a fair bit of searching I recently located and bought one of these (17059263) for a 1979 10th anniversary trans am 400/4 speed that I restored. I paid a kings ransom for it since they are rare. I wonder how many of these have been lost by being swapped at the parts store for a generic rebuilt Quadrajet by owners that didn’t know what they had.

[@Formulabruce]

I run these 800 Q Jet carbs. Cliff Ruggles recommends them, and for good reason. On the top, the APT, which is under the visible plug under the air cleaner base gasket, is key for giving these engines the right mixture with todays alcohol in the fuel. when rebuilt correctly, for the exact application, they can and do run like fuel injection. I "think" the screen is a spark arrestor. Great Vid Tyler !!

[@ZachIsOP]

I have a factory 77 W72 400 trans am with one of these carbs on it, slight differences because of 77 and 4 speed manual. Just rebuilt it and man does it roar, still need to tune some but it is real nice.

[@davida1hiwaaynet]

Back in the day, I removed the dual-jet two-barrel carb from my 1972 Chevy Nova (307) and installed a Quadrajet. I don't remember the style, it was a junkyard part. All I do know is, it DOUBLED my fuel milage from the original two barrel, and the car started up MUCH easier and all around ran better. Now, the Nova has a TBI fuel injected setup. That is another step ahead in milage, drivability, and power.

[@dansmith6990]

the only way it would've doubled your fuel mileage is if your two-barrel was completely out of tune

[@williamhelus3522]

One of my favorite. Holley is on the bottom. BullyBilly

[@whiteoak60]

Thats a W-72 special performance quadrajet off a trans am Rare carb!

[@TylersNeighborhoodGarage]

Correct.

[@chrisreynolds6520]

I grind a small half circle in line with that port on the Q-Jets I build. See my 383 running in my videos. On the primaries alone super responsive.

[@rangerpru]

Thought that it looked familiar before you even identified it. My Mom had a 1977 Pontiac Bonneville with the 400. It ran really great. I remember the car always started with one turn of the key. The same could not be said for many other cars of that era.

[@fredmauck6934]

I recognised it as well, I have a 17059263 on my 79 Formula. I have followed Cliff Ruggles book and rejetted for todays fuel. It runs a predictably as Fuel Injection, 45 years later.

[@doughboy1966]

That is the exact carburetor we used on our dirt track cars back in the day. Kinda hard to find and the Buick is even harder to find.

[@wlc1980]

I have a 1976 Trans Am version 800CFM I’m restoring. I was told the screen used over the middle vent is to help control venting pressures and spewing due to higher flow rates into the bowl. If someone heard different please advise. Good video! You sound like you have a Georgia accent.

[@TylersNeighborhoodGarage]

LOL Alabama. Those Pontiac Qjets had a lot of tricks from the factory.

[@repete2362]

i have the q jet for a 1970 olds W-30 455 4 speed . that carb didn't have primary rods . there is a brass cup like a freeze plug blocking off the plunger hole i believe it had 58 jets . it is a 750 cfm so that is a rare q jet.

[@Mail4dalej]

Carbs are sexy. Everyone talked about them in the day. Rode in a '76 Trans Am; that thing sucked serious air. No one every talks about the fuel injectors your running.

[@TylersNeighborhoodGarage]

I agree, we had a couple TRans-Am's of that era. Cars are tamed down now a lot, just like everything else.

[@drjohnsonhungwell5115]

I had a q jet on a 70 Buick skylark was the best one I've seen would open up with no bogging and would burn the tires up with little effort .

[@Poopdogsays]

I know this is an old video, but i put up an homage to your Pontiac Q-Jet video on my channel. Feel free to check it out.I have the same carb, but mine was built in august of 77. A carb/engine Ive owned since 95! Thanks for the very informative videos celebrating the most amazing sounding carb ever!

[@chrisreynolds6520]

The 80s truck carbs are the same casting as the Edelbrock Performer RPM and flow 850 cfm when the air door is properly adjusted. Find them on lots of 305 and 350 trucks and vans. I have several of them 17083226 and 17084226.

[@jamesduffus4455]

the screen is a flame arrestor they were worried about fires in the scoop getting out of control. in the event of a backfire

[@brucebehnke4858]

never heard you talk about the 2 dairy spring tentioning underneith the choke pull off rod?please tell what you think!how should that be delt with?

[@teyes400]

I currently have a 77 sbc 400 in a 77 van. I have this carburetor i saved from an old pontiac I sold. Can I use this carb on my 400 sbc?...i was gonna buy a edelbrock but I happen to like quadrajets. Th350 trans, but gonna change that to a 700r4.

[@YoCatGaming]

I watched this video and went out to the garage to check the carb off of my bird and it seem as though I've got one of these. I don't think you ever made a video on limited flow QJets did you?

[@TylersNeighborhoodGarage]

No I didn't. That's a good idea, though.

[@stupidman9774]

dirt dobbor prevention. many people would run with breather lid set 1/2" above filter.

[@DayRider76]

I Have a 76 400 800cfm, Basically Identical with the exception of the large port above the fuel filter, glad I stumbled on this vid, I just realized I have gasket interference on that front fuel vent? going to have to look into that?

[@TylersNeighborhoodGarage]

What kind of gasket interference?

[@snermaniv]

you forgot to mention the induction noise Howell.

[@TylersNeighborhoodGarage]

lol yes

[@keithsanville1665]

You say you see the screens on the Pontiac carbs,this could be because they have ram air systems,keeps the bugs out

[@xmo552]

The screened vent makes sense to keep bugs out due to ram air.

[@xmo552]

Also... I'm thinking since it would need a filtered air vent (to keep ram-air'ed bugs out of the carb guts) maybe that's why they moved the vent outside of the regular air cleaner gasket but still inside the filter..... using that extra port above the fuel inlet. Can anyone confirm or correct my hunch?

[@billharner8224]

That is a flame screen. Stops a backfire flame from traveling through

[@michaelreardon7667]

The air filter keeps the bugs out

[@barneywarwick1038]

is there a q jet for a 318 motor mine is a 93 318

[@TylersNeighborhoodGarage]

Yes, they exist as standard equipment on 1985-88 318's and 360's. The Magnum takes it's own intake.

[@RetroVintageItems27]

Very interesting system, what did that particularly come off of? I'm guessing that really sucks up gas with that wide diameter fuel "spritzer."

[@Formulabruce]

+Ben's Collection and Sundry The carb in this vid is a # 17058274 , its a M4MC as stated in the vid, which means it has a choke ON the carb ( vs a divorced choke on the intake) and its considered modified by Rochester. Its from a 1978 Pontiac 400 Engine with a TH350 Transmission.

[@Fullthrottle440Garage]

Interesting