Q-jet Questions

[oldskool]

OK guys, I see that NHRA now allows specific number Edlebrock Q-jets.

So, is there an advantage to using the E-carb ?

Do they have less smog restrictions than the later '70's carbs ?

I see specific casting numbers listed for factory carbs. Will they let you run any others, as long as they are the same cfm ?

Exactly what mods are you allowed on the carb ?

Do most guys run without the primary metering rods ?

Are the carb rules any different for Super Stock than Stock ?

I assume there are guys who can build your Q-jet so it will make more power than most, but still pass tech ? Or do most guys do their own ?

Any other useful info about making big power with a Q-jet ?

Thanks !

[GTX JOHN]

My understanding is that if all internal dimensions are correct for
either the 750 or 800 whichever is legal.........The carb is legal.

I have not seen them inspect the numbers for many years in teardown.

The Edelbrock come in either 750 (1901 /1902) and 800 (1903/04/05).
The only differences I recall is the linkage locations for GM or Mopar or
Ford within each size.

I have had the best success by far with the Edelbrock Carbs in Stock
and SuperStock.

George Thomson in Acton Ca. (Carb. Flow Engineering) has built my most successful carbs.

[oldskool]

Hey John. Thanks a lot for the info.

I sorta figured the E-Q's had a bit less smog restrictions in 'em.

[Danny Ashley]

1. No advantage
2. No. Edelbrock carbs were built from the molds from Rochester purchased by Magneti Marelli . The 1901 and 1902 were made using the 1973 and 1974 molds the only difference is Edelbrock installed .050 air bleeds in the air horn
3. Yes
4. You can increase fuel flow but not air flow
5. Yes
6.No
7. Most use a professional builder
In a nut shell, you are at the mercy of the core as far as if you end up with a good carb or a not so good one. No builder can make a bad carb good. Fact is some carbs are just better than others and the only way to know is to run it down the track. A Quadrajet may show more HP on a dyno yet be slower on the track. I will tell you this, the fuel bowl is what makes or breaks the Q-Jet. Smart racers will take a number of bowls to the track and keep swapping them until they find the best one. Hope this helps.

[oldskool]

Yeah, thanks Danny !

I reckin it's sorta like the heads. If you must used unported heads, then obviously, some of 'em will flow more than others, or produce quicker ET's for whatever reason.

That brings up another question. Do most of the quick Stocker guys gather large numbers of heads and do flow bench testing on 'em to find the best ones for their engine ?

I realize that heads for some of the older cars are getting harder to find. But I'll just use the Pontiac 6x heads for an example. These heads are quite common and cheap. So somebody with the $ to spend could by up large numbers of these heads, and identify the best ones on a flow bench. So is this type of thing a common practice among Stock racers ?

[oldskool]

Would some of you guys give me the names and CONTACT INFO of some of the good Q-jet builders ?

Now, I'm not talkin about some buddy you have who can do 'em for you. I'm talkin about guys who will build 'em for anybody with the money to pay for 'em. Maybe some guys who have built 'em for top qualifiers and national record holders. You know--the go to guys for a quick Q-jet.

Thanks in advance for this info.

[Bill Diehl]

Originally Posted by oldskool

Yeah, thanks Danny !

I reckin it's sorta like the heads. If you must used unported heads, then obviously, some of 'em will flow more than others, or produce quicker ET's for whatever reason.

That brings up another question. Do most of the quick Stocker guys gather large numbers of heads and do flow bench testing on 'em to find the best ones for their engine ?

I realize that heads for some of the older cars are getting harder to find. But I'll just use the Pontiac 6x heads for an example. These heads are quite common and cheap. So somebody with the $ to spend could by up large numbers of these heads, and identify the best ones on a flow bench. So is this type of thing a common practice among Stock racers ?

Since I just been through this rodeo...there is more to be gained by the proper valvejob than there is in testing heads. This pertains to my combo, the Boss Ford, which happens to be one of the highest flowing "stock" heads on the planet...your mileage may vary on other combos though