Recommend a tunnel ram/carb BBC

[F-BIRD'88]

I agree the 8-71 would rock. Especially if foundd the CR is low on this 454.

[af2]

Forget everything you need this!!

[Little Mouse]

Looks great for me the 4 small round air cleaners would have to go.

[F-BIRD'88]

From a visual standpoint it is impressive and interesting.
Some basic mistakes were made in the plenum .

[af2]

From a visual standpoint it is impressive and interesting.
Some basic mistakes were made in the plenum .

Have you seen the plenum? or are you looking from the outside?

[F-BIRD'88]

Read the article. The Plenum was IR design.
This was a big mistake. They realized this eventually.
They actually started out in a earlier mock up, with a better design. The 4 qjets With a open common plenum.
The Qjet is not suited as a IR carb.
Their dual qjet set up worked pretty good.
I have a better setup. The SIX Shooter setup is Better for both Dual QJets on a Tunnel Ram and for 4 Qjets on a tunnel ram. The linkage is a lot simplier.
My dual qjet used 6 venturi.. And the quad setup uses 12 venturi. Carbs are inline (dual). Or inline pairs mounted sideways on the intake. This puts the "primaries" of each group in the center over the grouped intake ports in the plenum. The secondaries suround the primaries in a very symetric and logical pattern over the intake runners..
No need to butcher the carbs workings other than disabling the front primaries of the paired inline carbs..
The front carb of the pair becomes a secondary only carb. The qjets secondary air door+ the vacuumbrake on the sec linkage that provides a adjustable timed delay of the start of secondaries air door opening and then rate of opening ensures the engine is not "over carbed" as the engine gains rpm as you open the th.rottle.
On the 4 Qjet setup the secondary air doors need not fully open at max WoT demand.. (The throttles open qide but the secondary air doors open based on engine air flow demand) The engine will take what it wants and the air door progression is adjustable in both rate AND slight TIMED DELAY OF TIP IN.
The early chev style QJet withright angled fuel inlet is best for this because they can be mounted closer together in pairs, inline. Not back to back.
This will work on a tunnel ram. It will work on a single 4 bbl intake. It will work on a cross ram manifold too.

[af2]

Please post your set up. I am intrigued!

[F-BIRD'88]

Please post your set up. I am intrigued!

I am discribing it. I have not built it yet.
This is the 6 venturi carb GM should have built based on the QJet fir the 427 bbc Corvette instead of the holley Tripower 1968-1969 427. The Six venturi "Qjet" would be a single carb body. 4 secondaries surrounding 2 center primaries. GM goofed on this. Would have only took minor retooling of the existing 427 single 4 bb manifolds plenum and carb flange to cast a dedicated Six Shooter, 6 venturi single carb body version of the 4 venturii QJET.
The venturi layiut is much more symetric, logical and powerfull. This would have worked on all the GM hi perf V8 engines with only minor revision of the existing 4 bbl intake manufolds. My 2 qjets SIX Shooter setup is prototype proof of concept deal. Using two existing qjets.
It should be built on a single carb body. Easy to make. Easy to mount. Easy to fix. Easy to tune. Some 1290 ish total cfm at WOT @1.5". Fully adjustable and Symetric.
It is also nicely suited for street strip supercharging on a Roots blower (draw thru) or for Blow thru. (In a sealed carb box)
It is better than a single 4 bbl. For all these.

[gmrocket]

Please post your set up. I am intrigued!

I am discribing it. I have not built it yet.
This is the 6 venturi carb GM should have built based on the QJet fir the 427 bbc Corvette instead of the holley Tripower 1968-1969 427. The Six venturi "Qjet" would be a single carb body. 4 secondaries surrounding 2 center primaries. GM goofed on this. Would have only took minor retooling of the existing 427 single 4 bb manifolds plenum and carb flange to cast a dedicated Six Shooter, 6 venturi single carb body version of the 4 venturii QJET.
The venturi layiut is much more symetric, logical and powerfull. This would have worked on all the GM hi perf V8 engines with only minor revision of the existing 4 bbl intake manufolds. My 2 qjets SIX Shooter setup is prototype proof of concept deal. Using two existing qjets.
It should be built on a single carb body. Easy to make. Easy to mount. Easy to fix. Easy to tune. Some 1290 ish total cfm at WOT @1.5". Fully adjustable and Symetric.
It is also nicely suited for street strip supercharging on a Roots blower (draw thru) or for Blow thru.
It is better than a single 4 bbl. For all these.

So easy to mount, easy to make, easy to fix, easy to tune, easy peasy...

But no pics, or drawing.....

That Olds pic with 4 quads on it was so bad, he had to drive with his wipers on because the fuel standoff was so bad....I'm surprised his exhaust didn't lite off the vapor trail

[F-BIRD'88]

It was only bad because of the IR plenum design. This was the goof up. The earlier open common plenum set up they did first, Worked !
I don't need pics and drawings. I am going to build it. Using 2 early chev QJets (4mv). Its not rocket science.

[F-BIRD'88]

I posted this before. Here it is again.
The primaries of the front carb are not used.
Not exposed to the plenum. But all linkage is kept intact except the bottom halfs of the primary throttle blade is cut off. Fuel passages blocked.
The engine idles and drives on the 2 center primaries.
When you "Rug it" all 6 throttles open and the secondaries air doors (2) both open based on engine air demand and air door spring tension and the vacuum delay brake valves on the side. Just like a single Qjet works. Except better and more powerfull.

[gmrocket]

It was only bad because of the IR plenum design. This was the goof up. The earlier open common plenum set up they did first, Worked !
I don't need pics and drawings. I am going to build it. Using 2 early chev QJets (4mv). Its not rocket science.

Nope, it didn't work,,,ever

I know the car and talked to the guy about why it ran like a turd,, from the start

[gmrocket]

It was only bad because of the IR plenum design. This was the goof up. The earlier open common plenum set up they did first, Worked !
I don't need pics and drawings. I am going to build it. Using 2 early chev QJets (4mv). Its not rocket science.

Nope, it didn't work,,,ever

I know the car and talked to the guy about why it ran like a turd,, from the start

It was just a parking lot shiny pony...it had to be trailered everywhere. Could barely make it across an intersection without falling on its face.

There are videos of him trying to make it run down the road,, while the windshield and roof got soaked by the fuel standoff..

[F-BIRD'88]

It was only bad because of the IR plenum design. This was the goof up. The earlier open common plenum set up they did first, Worked !
I don't need pics and drawings. I am going to build it. Using 2 early chev QJets (4mv). Its not rocket science.

Nope, it didn't work,,,ever

I know the car and talked to the guy about why it ran like a turd,, from the start

I could fix that in about 15 -20 minutes.
I can tell in the article they did not have a good handle on carbs nor QJets nor setting up a engine with a tunnel ram on it. It will work with the 4 Qjets as they did or with 2 q jets back to back or inline. It will be smooth as silk better than 1 single q jet. They made basic mistakes. Their cam was not the problem either. The plenum was the big problem. A few other lil thibgs they over looked. Lack of knowledge. Lack of experience with tunnel rams.
But they had fun.
The fuel standoff was caused by the IR plenum layout.
Not gona work with QJets.....

[F-BIRD'88]

I'm not doing the 4 Qjets. But it will work. (Not IR plenum)
(Especially on a racey 8-71 blown BIg Block)
I'm doing the 2 Qjets "Six Shooter" deal.