[straycat]

One of my friends wants to remove the E carb on his 65 Tempest. It's a nice running car with a 78 400, headers, E Performer RPM intake, RA 4 cam, late model 4 speed and 3.42 rear. It's not the best combo ever but has run a best 13.13 with street sticky tires which I thought was pretty good. 95% of the time the car is street driven but he'd like to get a 12 second time slip this year. My thought is a change to a Q jet will give him the best chance. Right now we have in our hands a 68 Caddy carb 7028237 from a 472. It has 70 primary jets with 44 rods and no secondary rods or hangar. So were going to tinker with this carb for the time being. Any suggestions for this carb such as jets and rods, power piston spring etc. Street manners are most important but he'd like that ET. Long range plan is one of Cliffs carbs.

[RamAirIV28]

Don't do it...

Q Jets are over rated

stick with the e/AFB

or

Go with a Holley

actually your first choice ought to have been a holley

Meow meow meow!

[Bruce Meyer]

Originally Posted by RamAirIV28

Don't do it...

Q Jets are over rated

stick with the e/AFB

or

Go with a Holley

actually your first choice ought to have been a holley

Meow meow meow!

Oh no you didn't! LOL!

[1969GTO]

Calling DR.RUGGLES there's a kat that needs to be skinned........meow

[68 Firebird]

I agree with the Q-jet myself. My unit from Cliff has been excellent.

Good Luck

Gerry

[77 TRASHCAN]

Originally Posted by Bruce Meyer

Oh no you didn't! LOL!

X2...........LOL
Mr. RamAir, no ill will intended....You haven't been in Pontiacville too long...have you???

Cliffshighperformance.com

[Lee]

Holley 700 double pumper.

Run dual feed lines made out of braided, to make jet changes quick and easy. Buy the big jet kit from Summit, some extra float bowl and meterblock gaskets, and have fun while learning to REALLY dial-in the carb.

[RamAirIV28]

Originally Posted by 77 TRASHCAN

X2...........LOL
Mr. RamAir, no ill will intended....You haven't been in Pontiacville too long...have you???

Cliffshighperformance.com

only since the late 70's when quadra...junk was summarily chitcanned and Holley ruled the world its in the nature of things that a superior spiecies evolves while lesser ones are only fondly if barely remembered.

you simply cant beat a holley

You can buy them cheap at swap meets, build them cheap and they work great

you ought to read David Vizards latest holley book.. pretty much sayz it all

[70pontiaction]

But it's much more fun to pop the hood and amaze that guy in a Crapmaro that you just smoked when you have a STOCK (wnk wink) carburetor on your engine.

Holley's can be tuned to have practically identical horespower, but the quadrajet - when properly set-up - will deliver as much as 5 more mpg than a Holley.

AFB = reasonable on gas but WAY down on horespower vs either Holley or Qjet. AND hard/impossible to tune.

I bought my first 1970 GTO in 1977. Had a 625CFM AFB on an Offy manifold. Ran good, decent performance, decent economy. First Pontiac, too. 15MPG.

Swapped it for a Holley 650 square-bore double pumper - UP on power, still drove good, down 25% in fuel economy (at least). 12MPG if I was nice.

Swapped that for another Holley - 800 spread-bore double pumper - lots MORE power, even less MPG, but only 1 or 2 MPG lower. 10 or 11MPG.

Finally located a correct 1970 quadrajet and tuned it with the HO Racing calibration kit (remember those?). More driveable, more power, more MPG than anything else. 15MPG on a bad tank (more fast driving) and around 18MPG if driving casually.

Left it alone after that - with the quadrajet. Still got it in the garage. You'll be happy with a properly calibrated quadrajet.

[Cliff R]

Might as well cut a hole in the hood, high rise intake, 3/4 cam, install some 2.02 heads, high volume oil pump, and double roller timing set and run even slower....oh, this isn't a Chevy thread, sorry.

Seriously folks, we just went into 2014 and 40 year old mentality is still alive and well here?

Anyhow, I still remember the first time my engine was on the dyno with my 1977 Pontiac q-jet, stock HEI and factory iron intake. The engine made great power from the first pull, and only got worse as we messed with timing an fuel curves. We did the KRE head swap, and made even more power. After it was all said and done (and I knew this was coming) someone said "let's bolt on this big Holley carb and see how power the engine will really make"....................On the very next pull, with no other changes, and the custom dyno tuned Holley 850DP in place................It LOST 2hp!!!

Yes, we didn't even ask for the test, a representative from the magazine doing the coverage asked for it, so they could get some additional info to provide to the readers in the articles that were coming. We also carried the Holley carb to the private track rental that followed, and the q-jet outran it every single time. Best part is, none of that information graced the pages of either one of the magazines in the articles that followed, wonder why?.........Cliff

[David Brown]

Q-jet! Especially since you use the car 95% on the street. People who still use the term "Quadra Junk" generally don't know how to set up a Quadrajet.

[A.W.Dille]

I have done the Q-jet to Holley testing back to back at the track back when I ran my GTO at National Trails in Ohio. Normally ran a 650 spreadbore Holley, ran a 13.84, bolted on a stock Q-jet I been given and put a kit in. Ran 13.85, then bolted on a borrowed 800 spreadbore and ran a 13.88. The q-jet didn't get the tuning I had put into that 650 and would have likely been faster but running nearly identical times showed that the Q-jet could do the job. Run a Q-jet on both the GTO and my Grand Prix and won't change. Plus with the help of Cliff's book and his tech advice on the phone the Q-jet is one of the best carbs to ever be made. My.02.

[george kujanski]

My opinion, without facts to back it up, but working with bothcarbs over the years, the qjet is a more "sophisticated" design, the holley is more of a brute force version, feed it enuf fuel and it`ll go

Sarcasm aside, the qjet seems to be better engineered as an oem carb, requiring good performance and economy. And is better than or

Add to that the expertise of Cliff and carbking, who understand and know how to tweak them, you have a winning combo.

The holleys are easier to tweak, requiring less disassembly and tools, it seems, and parts are readily available, in my opinion.

George

[straycat]

Cliff, We are thinking gear drive for the cam.

[Ventura455]

Run a Holley Hp carb. It will run circles around that Q jet. Did I just say that? Yes I did.

[Cliff R]

Tried that deal too, back to back tested an HP950 on the dyno and again at the track, and outran it both places with my q-jet. This simply happens because the q-jet is custom tuned EXACTLY for the application, and I'm using a dual plane intake, which favors the spread bore design. If I spent time custom dyno and track tuning the HP carb, it would have ran the same, or very close to it. Same deal if I swap on a single plane intake, which favors square flange carburetors, the q-jet isn't going to work as good there, been there and done that as well.

No rocket science going on with this stuff, no matter what you choose to use on your engine, it must be set up for your engine, exactly, in every area, if you want to get the best end result. Once folks quite beating their chests and look at what's really going on with these things, being brand specific is no longer part of the equation. If you spend the needed time/funds on a carb big enough for what you are doing, it's going to work as well as any other carburetor with the same thing done to it. There are some minor exceptions to that logic, if you are pissing around with the Edelbrock AFB clones, for example. They lack any way to tune secondary transition, so if it pukes all over itself, even after you get the A/F correct across the load/speed range, there is no way to correct that issue that I know of. If you are a lover of that design, at least step up to their AVS version (Thunder Series), we track testing them and the results were 200 percent better than the non-adjustable AFB clones....FWIW.....Cliff

[Ventura455]

[QUOTE=Cliff R;5108602]Tried that deal too, back to back tested an HP950 on the dyno and again at the track, and outran it both places with my q-jet.

Really...Was that test with your Ventura motor? Whats in that Ventura of yours anyway?

[rexs73gto]

I tried the Holley test to I had a Holley HP 770 & it was ok , my car ran an 1196 I went back to my Q-jet that I tricked out to some of Cliffs specs & now the car runs 1174 with only the carb change. I use to be in that mind set where the Holley was better but I am now back to what really works & that my Q-jet. Use the Q-jet as you will be much happier all the way around. By the way if you want that 770 HP it's for sale as it now just sits on the shelf.

[poncho in a can]

Afb "clones" are not that good at optimizing atomization. Sure they can run good but if you want more efficiency, the Q-jet is much better with its dual booster design and small primaries. holley carbs are good at wot . but the transitions are not as accurate during other throttle angles. So in this case, with the driving 95% on the street, I would find a Q-jet from the late 70's and go through it. One little secret is that mid eighties dodge vans and pickup (usually with a 360) use a Q-jet that has a real nice fuel curve, not lean at all and they are non-electronic to boot. they are also 800 cfm units and for some reason they usually seem to be relatively untouched and not warped. The bad about them is the mopar linkage and the side entry fuel inlet (like a chevy).

[Ventura455]

Originally Posted by rexs73gto

I tried the Holley test to I had a Holley HP 770 & it was ok , my car ran an 1196 I went back to my Q-jet that I tricked out to some of Cliffs specs & now the car runs 1174 with only the carb change. I use to be in that mind set where the Holley was better but I am now back to what really works & that my Q-jet. Use the Q-jet as you will be much happier all the way around. By the way if you want that 770 HP it's for sale as it now just sits on the shelf.

770 hp ..there is no such carb.