Q-jet experts , couple questions

[Redlight]

Thanks, so far, I think?

I guess I have to tell he "rest" of the story. I have been running with A Holley.

Trying something different, a set of Q-jets on a old Offy intake.

The carbs are Buick bases, Chevy bodys and Pontiac tops so alot of the cobbling had been done.

I dug around my library and low and behold, found Roe's book circa '81.

Giving myself a refresher.

I will keep them away from the bridgeport for now.

Oh Lynn, they are sitting on a Pontiac!

[Neil Smedley]

I have put a 750 holley on a few stock elim cars just to see how fast they could REALLY go.......granted, a high dollar q-jet will perform just as well but who wants to spend the bucks ?

[Bruce Fulper]

Originally Posted by Neil Smedley

I have put a 750 holley on a few stock elim cars just to see how fast they could REALLY go.......granted, a high dollar q-jet will perform just as well but who wants to spend the bucks ?

Neil:

How dare you be rational? Only true engineers know how to cross the dyno finish line first.

hahaha...!

Hope all's well in r-e-a-l h.p. land.

c-ya

[Glenn Hayes]

Originally Posted by Lynn A McCarty

I have bracket guys running Q-jets and the love them. You dont have th carry a bucket full of jets and gaskets everywhere you go. You can get away with substandard fuel delivery with a Holley due to the larger fuel bowls and inlets, but otherwise the Q-jet is pretty damn cheap.

I spent a lot of time with the Q-jet guys in Rochester, NY. You guys wouldnt believe the technology of a Q-jet. They still state that the Q-jet was the closest carb to actual fuel injection ever made.

Lynn,
What is the ideal fuel pressure to have for the Q-Jet ?
What is the best S.B. Chevy performance intake manifold to use and modify ?

Glenn

[Redlight]

"Rational" or not , I am going to use the Q-jets.

I would appreciate if we stayed on topic, not Holley vs..........

The fuel system is up to par, all Mallory components, proper size line to and from (return), good wiring etc etc. Fuel is steady and feeds 630 hp just fine.

The present pump is a 140 but have a back up 250 if it is needed.

[Greg Hill]

If you are changing from a Holley to a q-jet you will need a better fuel system. The mallory 140 pump probably will not do the job. The 250 with a 1/2 inch line is the minimum.

[Redlight]

Greg, I am going from a (single)Holley to 2 Qjets.

Do 2 Qjets hold similar volume of fuel as 1 dominator with standard bowls (no extensions)?

Do you think the 250 is still needed?

I am kinda type "A" with fuel and wiring.

Here is the present system:

8 Gallon cell with dual #8 outlets from the sump,(2) #8 mesh filters to a Y with #8 inlets to a #10 out direct to the pump, #8 line to the front mounted paper filter,#8 fitting dirct to the regulator, dual #8 outlet lines to the carb, the return is also #8.

There is only 1 90 degree fitting (full flow) and it is on the high side before the regulator.

The cell and pump are mounted in the trunk,high. If I remove the lines up front at the carb, fuel will gravity feed!

[tj310]

You only need more fuel if you are going faster
Thanx Trevor

[Greg Hill]

I don't know. I've never heard anyone try to run 2 q-jets.

[Alan Roehrich]

Two Q-Jets do not hold as much fuel as a single 4150 or 4160 Holley, never mind a Dominator.

To run Q-Jets, you need serious volume, without high pressure. Often you'll find you can't even run 7 psi with the 0.130" needle and seat.