[Riku]

My current carburetor might not be perfect for my engine.
I´ts 670cfm Holley Street Avenger with 1" 4-hole adapter on factory 9790140 intake.
It´s working alright and tuned in dyno. However, I´d like to know alternatives and what members here are running in street engines? Trued and tested.
I have Q-jet by Carter number 7042272 on shelf that needs complete rebuild, but
I´m not sure if it´s worth of effort and expenses.
It´s originally from 455 ´72 GTO with automatic transmission. It was taken out from running engine due to leak from gasoline inlet.
Hey Cliff, what is your opinion. Is this carb worth of for a complete/correct rebuilding and custom tuning for hi-perf use in my combo? How much you estimate it´ll cost made in your place?
Hi Paul, (Carter) could you ask from Jeff what is his suggestion for carb and how much is his estimation for costs for custom tuning?
This is street / road car so the main point is not in best possible hp but good combination of hp/mpg. I want to keep the original intake, and carb should have vacuum secondaries and electric choke.
My combo is here:
http://forums.maxperformanceinc.com/...d.php?t=817331
Thanks

[Formulajones]

If you want to run the factory spread bore intake, I'd personally go with a Q-jet. I've never seen any of the square bore to spread bore adapters work all that well as far as HP on the dyno, so I don't use or recommend them.
They work, but not optimum.

[Chief of the 60's]

One of the best right here - http://www.pro-system.com/

Custom built to your engine's specs for about what you will pay for a good carb.

[Tom Vaught]

Riku, Jeff, Shaker455 could build you a very nice Q-jet Carb as could Cliff R. and it would run great on your stock intake.

Not a big fan of adapting a Holley carb to a Pontiac factory style intake.

Patrick James at Pro Systems builds $1000+ Holley carbs for racing (which is the last thing the man needs for his engine (in the link).

Tom V.

[Chief of the 60's]

Originally Posted by Tom Vaught

Patrick James at Pro Systems builds $1000+ Holley carbs for racing (which is the last thing the man needs for his engine (in the link).

Tom V.

WRONG

$706.00 to my door - Bolted it on, adjusted the idle, went 10.97

A plain old Holley HP will set you back $695.00 and you will have to screw with it. And everyone knows a Holley carb is 1000x better than a Q-jet or Edelbroke/Carter AFB.

[ponyakr]

"... everyone knows a Holley carb is 1000x better than a Q-jet..."


WOW ! What a ridiculous(IMO) statement to make, on a site like this, where MOST recommend & use a Q-jet, on street engines. .

Even the Stock & SS racing Pontiacs run 9's & 10's with 750 Q-jets.

So, with 9 sec potential, and the proven streetability of the Q-jet, how could anybody think a Holley is 1000x better than a Q-jet, for a street driven Pontiac ?

Here's a quote from Cliff.

" One of our customers uses a later model large cfm unit at 750hp. His car runs high 9's in the 1/4 mile at 136mph. He has at his disposal a Quick Fuel 1000cfm Holley, it runs no faster anyplace than the q-jet.

We have a Super Stock customer running mid-9's with a small block Chevy using a smaller "750" cfm unit, built from an early 1970's Chevy divorced choke truck carb.

My own engine uses a 1977 Pontiac carb, it makes close to 600hp, and powers my daily driven 73 Ventura to low 11's at over 120mph.....Cliff "

[Tom Vaught]

Let it go, ponyakr, everything that you posted in your reply about Stock & SS racing Pontiacs running 9's & 10's with 750 Q-jets is valid.
That being said, the man is after a street carb for his street engine and this is the STREET section.

Tom V.

[Chief of the 60's]

I forgot to mention, I get 18 mpg on the street running pump gas. Also running a GM OD.

[ponyakr]

"...the man is after a street carb for his street engine and this is the STREET section."


So, does that mean that you also think a Holley is 1000x better than a Q-jet, for a STREET Pontiac ?

Sure reads that way.

Here's part of what I said.

"...the proven streetability of the Q-jet, how could anybody think a Holley is 1000x better than a Q-jet, for a street driven Pontiac.."

Here's what Cliff said.

"...1977 Pontiac carb, it makes close to 600hp, and powers my daily driven 73 Ventura..."

So, why do you think we are only talking about RACING Pontiacs ? The reason we mentioned the ET potential is obviously just to show that a guy don't have to give up a lot of power because he chooses a Q-jet over a Holley. Just curious as to how you could miss the STREET part of what we said.

[Tom Vaught]

Originally Posted by Riku

My current carburetor might not be perfect for my engine.
I´ts 670cfm Holley Street Avenger with 1" 4-hole adapter on factory 9790140 intake.
It´s working alright and tuned in dyno. However, I´d like to know alternatives and WHAT MEMBERS ARE RUNNING IN (THEIR) STREET ENGINES. Trued and tested.
I have Q-jet by Carter number 7042272 on shelf that needs complete rebuild, but
I´m not sure if it´s worth of effort and expenses.
It´s originally from 455 ´72 GTO with automatic transmission. It was taken out from running engine due to leak from gasoline inlet.
Hey Cliff, what is your opinion. Is this carb worth of for a complete/correct rebuilding and CUSTOM TUNING for hi-perf use in MY COMBO? How much you estimate it´ll cost made in your place?
Hi Paul, (Carter) could you ask from Jeff what is his suggestion for carb and how much is his estimation for costs for CUSTOM TUNING?
This is STREET / ROAD CAR so the main point is NOT in best possible hp but GOOD COMBINATION of HP/MPG. I WANT TO KEEP THE ORIGINAL INTAKE, and CARB SHOULD HAVE VACUUM SECONDARIES AND ELECTRIC CHOKE.
My combo is here:
http://forums.maxperformanceinc.com/...d.php?t=817331
Thanks

I was going by these words in his original post.
Ponyacr, are you replying to me or to Chief **60s?

1) The words in the quote are his words. I just capitalized some of them.
2) He wants to keep the STOCK Pontiac Intake
3) He wants a GOOD COMBINATION of HP/MPG
4) He wants VACUUM SECONDARIES AND ELECTRIC CHOKE

Holley to Q-Jet manifolds suck unless you use a spread bore Holley carb. Spread bore carbs come in 650 and 800 cfm combinations.
Patrick James builds his carbs based from HP mainbodies (no choke provision) or from Dominator castings. In my opinion the Q-Jet is a better FE carb vs a Spreadbore Holley. The Holley spreadbore carb just bolts on a factory intake.

I was just going by the man's selection of parts. (If you were replying to me).


Tom V.

[Sirrotica]

In my own applications on dirt track race cars, autocross cars, as well as street cars I have tried both Holley carbs as well as Q jets. I have never given up any performance using a Q jet over a Holley. The Rochester is as cheap as you can get, people will just give them to you for free, because as everyone knows, they're junk, hence the misnomer Quadrajunk.

To the uninformed they're 1000X worse than a Holley, LMAO.

I hope the uninformed will keep believing they're Holleys are 1000 X better or my supply of free carbs will dry up. I'd hate to have to pay $700 and change for a Q jet dropped at my door.

If some of the guys that ponied up the money to build aftermarket Pontiac blocks feel the need to build dies to cast up some new Q jet castings it would be wonderful, not going to hold my breath on that one though. If it did happen I'd probably be paying $1000 for a carb that was 1000X worse than said Holley carbs ....................................

[Tom Vaught]

Sirrotica, as you and others know, I actually worked for Holley carburetor in the 70s at their Engineering Center in Warren, Michigan.

I do not think I ever heard or saw an ACTUAL Holley employee bad-mouth a Rochester Carburetor or a Carter Carburetor.

Some Modifiers bad-mouthed a different brand carb from what they sold.

Brad Urban, RIP, from the old Carb Shop in California, could build any carb and it would run very well. Never saw him bad-mouth one carb vs another and he sure never said a Holley was 1000 times better vs a Q-jet.

But again this a the street section and the guy wants to use his stock Pontiac manifold (which guys in racing have proven to work very well in given single 4 bbl applications). Q-Jet is my vote.

Tom V.

[Chief of the 60's]

Originally Posted by Riku

My current carburetor might not be perfect for my engine.
I´ts 670cfm Holley Street Avenger with 1" 4-hole adapter on factory 9790140 intake.
It´s working alright and tuned in dyno. However, I´d like to know alternatives and what members here are running in street engines? Trued and tested.
I have Q-jet by Carter number 7042272 on shelf that needs complete rebuild, but
I´m not sure if it´s worth of effort and expenses.
It´s originally from 455 ´72 GTO with automatic transmission. It was taken out from running engine due to leak from gasoline inlet.
Hey Cliff, what is your opinion. Is this carb worth of for a complete/correct rebuilding and custom tuning for hi-perf use in my combo? How much you estimate it´ll cost made in your place?
Hi Paul, (Carter) could you ask from Jeff what is his suggestion for carb and how much is his estimation for costs for custom tuning?
This is street / road car so the main point is not in best possible hp but good combination of hp/mpg. I want to keep the original intake, and carb should have vacuum secondaries and electric choke.
My combo is here:
http://forums.maxperformanceinc.com/...d.php?t=817331
Thanks

Hmmm.... The guy is running a Holley, why not put another Holley on it. The guy is also from another country. So buying a good carb similar to what he is already running that is ready to rock n roll would be the smart thing to do. A good carb is going to cost $450.00 - $700.00, then he will have to play with jetting etc. perhaps resulting in more needed parts he may have to wait a month or longer for. Talking to Pro-Systems only costs a phone call and it could get him a carb built to his engine's specs (no more), he will be able to bolt it on and go. Nothing else needed and 100% tech service a phone call away 24/7/365. It is the simplest solution for him to do in his position and that he is already running one. Yes, they built the "world's fastest carb" but that does not mean every carb they build is for racing. I am surprised that a guy that has a whole thread about Holley carbs, bashes one. Really surprised.

[Sirrotica]

Originally Posted by Tom Vaught

Sirrotica, as you and others know, I actually worked for Holley carburetor in the 70s at their Engineering Center in Warren, Michigan.

I do not think I ever heard or saw an ACTUAL Holley employee bad-mouth a Rochester Carburetor or a Carter Carburetor.

Some Modifiers bad-mouthed a different brand carb from what they sold.

Brad Urban, RIP, from the old Carb Shop in California, could build any carb and it would run very well. Never saw him bad-mouth one carb vs another and he sure never said a Holley was 1000 times better vs a Q-jet.

But again this a the street section and the guy wants to use his stock Pontiac manifold (which guys in racing have proven to work very well in given single 4 bbl applications). Q-Jet is my vote.

Tom V.

As I said I've used both in racing as well as street, I bought Doug Roe's book many years ago for Q Jets and this as well as turning wrenches everyday on Q jet equipped OEMs, it gave me the perspective I have. Besides free is tough to beat on the price you pay for carb cores.

I actually like Carter carbs too, but they need help when being used on oval track engines because of the vent tube arrangement. The vent tubes on the left side of the carb have about maybe a 15-20 degree angle and upon entering a turn will dump fuel from the float bowl directly into the left venturi area. Just making modifications to the vent tubes can bandaid the problem. Years ago people made wedge shaped spacer plates to angle the AFBs left to right to also help with the engineering design problem when being used in oval track applications.

Not bad mouthing any carbs, I'm just saying if your going to run a Pontiac powered dirt car as I have, you can depart from all the so called logical norms and run a Q jet carb, a T 400 transmission, and back to back twin radiators and have everyone in the pits scratching their heads and wondering why you can not only run with the SBC guys, you can beat them. The look on their faces is "PRICELESS"................

FWIW, when the local race track adopted a 2 BBL rule on the lower street stock classes the guys I was helping by building engines for also ran my one of my Q jets on their cars. After implementation of the 2 BBL rule everyone was buying the Spec Holley 500 CFM carbs at about $350 each. The guys I was helping were pretty poor so I offered to rework a Rochester 2GC for them. I spent a good deal of time boring the venturi bores, polishing, contouring throttle shafts, etc. and totally reworking the 2GC. It would run with, or quicker than, the Holley equipped cars.

It's all relative, if you want to work on a carb and put some TLC in it you can make it as good as or better than out of the box stuff.

[Riku]

[QUOTE=Tom Vaught;5876746]
...Holley to Q-Jet manifolds suck...
Hi Tom what is the disadvantage when adapting 4150 style carb to Q-jet manifold?
i.e. What do I loose?
Hi all, how about this 7042272 that I have. Are these Carter made Q-jets somehow different than Rochester made? I´m hesitating in putting hundreds of $ to rebuilding old carb that is not original for the car. Anybody using SMI Q-jets? How is the quality and craftsmanship?
Chief of the 60´s, (QUOTE So buying a good carb similar to what he is already running... ) Good point. Considering I´m not very familiar with Q-jets.
As for intake, the main reason for staying with existing manifold is that it´s original to car and in excellent condition. I´ve understood it´s good manifold and supports easily my hp levels.

[Formulas]

Boy this thread went sideways in a useless way.

Riku any brand carb to manifold adaption is undesireable whether it be holley to Q or Q to holley forcing large to small and small to large openings disrupts total flow and atomization resulting in less than optimun power and efficiency its just best to use a carb and manifold that were designed to compliment each other.

Open plenum single plane intakes are less of a problem because of the nature of the large open plenum /area right under the carb no constrictions or sharp turns

[John Milner]

I'm not sure I would mess with it if it runs good and you are happy with it and you are just driving on the street. Nothing wrong with a good working quadrajet, though. If anyone talks bad about one they probably just don't know how to work on it.

[tom s]

Sean at SMI builds good carbs,Got his training from Brad Urban.He has done QJs,Holleys,AFBs and tripowers for me.He like Cliff actually drive and do QJs.Tom

[Cliff R]

The 7042272 is a nice unit, divorced choke so you'll need the factory intake and choke stove if you want a working choke. It's 750cfm, and PLENTY of carb for what you are doing, and light years ahead of the Holley Street Avenger at every level.

I was unfortunate enough to spend some time with a brand new Holley Street Avenger over the past year, trying to help out a friend who got mixed up with a local SBC "guru" for his engine build, also the guy was a Q-jet hater. After pissing around with the "guru" and the Street Avenger for nearly a year we replaced it with a Q-jet. Fuel mileage is over twice as good, instant cold starts in any weather, and dead solid reliable in his application (daily use work truck)........Cliff

[Tom Vaught]

Originally Posted by Chief of the 60's

Hmmm.... The guy is running a Holley, why not put another Holley on it. The guy is also from another country. I am surprised that a guy that has a whole thread about Holley carbs, bashes one. Really surprised.

1) Cliff and others have posted that his 272 carb would be a fine carb to put back on his stock Pontiac Intake.

2) Formulas has posted why adapting a Holley carb on a stock manifold typically is not the best idea.

3) Sirrotica and others have posted about their successes with running a Q-jet on their engines.

4) Just because I worked for Holley does not mean that I owe Holley carb anything today.
Holley carburetor has gone bankrupt several times since I worked there. I try to give good advice on Holley carbs not just wave the flag because of employment at one time.
Some of Holleys stuff is not as good as the old stuff when GM and Chrysler were throwing big bucks towards the carb designs.
So I wrote a thread about how to identify different parts and circuits on a Holley and what they actually do.
How does the carb thread relate to my opinion, that for this man, the Q-Jet probably would be a better choice?

If the thread went south it is because of one individual and that individual was not me.

Tom V.
Sean, Cliff, Jeff (Shaker455) and others could build the man a very nice Q-Jet. Sell the Avenger to someone else.