QUICK FUEL Q850 CALIBRATION

[chaz1201]

Im trying to find a starting calibration for a quick fuel/proform Q850. it is a 1.390 venturi and 1 3/4 base plate with billet quick fuel/proform metering blocks. The blocks have 4 emulsion holes that are tapped but no restrictors. The holes have a .028 hole drilled in all 4 emulsion holes. The pvcr is .059 and the ifr is .044. It has 70 iab and 33 mab. Jetting is 71 p and 85 sec with a 6.5 pv in the primary. I purchased the carb used and it dont seem like the factory calibration. For drag race only (no street driving) should it have a power valve?
The engine combo is a 415 cu in sbc with fully ported 18* heads, 14:1 compression, solid roller cam 050 = 269/277, .740 lift, 112 lobe sep.
Engine should make power around 7500 and go through traps 7500-8000. I dont want to have any issues when we run it on the dyno.
Do you guys think the above calibration is close or do you have something that would work better.
Thank you in advance
Charlie

[hipockets72]

Someone has been into that carb. The IFR are huge, jets are changed, and the bleeds also.
Proform shows 78/88 jetting, 4.5 pv, 70/35 air bleeds, 33/33 squirters.
A Brawler 850 which is the same comes with 76/84, 4.5pv, 73/34 air bleeds, 32/32 squirters, .036" IFR.

I would change the IFR to .033", bleeds to 70/28, jets to 74/84, 6.5 pv, .082" t slot restrictors in the main body both primary and secondary, and emulsion only 2 open .028" in each stack. Thread blanks in the others. Top to bottom .028", closed, .028", closed.

[chaz1201]

Thank you for your help

[rgalajda]

"Im trying to find a starting calibration for a quick fuel/proform Q850. it is a 1.390 venturi and 1 3/4 base plate with billet quick fuel/proform metering blocks."

A little confusing what you have. Proform or Quickfuel

Q850 .........Q-SERIES CARBURETOR 850CFM DRAG RACE https://www.holley.com/products/fuel_sy ... arts/Q-850
I believe these are 1.570 venturi 1 3/4 throttle bore ( correct me if I am wrong )

Brawler Street series.............with choke ......1.570 venturi 1 3/4 throttle bore

[rgalajda]

Or this: https://www.quickfueltechnology.com.au/ ... s-AUST.pdf



Q-850 Venturi 1.390 1.390 Throttle Bore 1.750 (1-3/4) Down Leg Prim 76 Sec 84 Idle bleed 73 HS bleed 33 Mechanical Secondary / Gas

[chaz1201]

The main body is a older main body. On the primary side of the body where the metering block bolts up it has quick fuel cast into it on the secondary side it has proform cast into it.
On the main body it also has Q850 stamped into it. The venturi measures 1.390. Billet metering blocks and baseplate.
I purchased it off ebay knowing i would need to go through it.

[Right hand drive]

[chaz1201]

It will be run on gasoline.
VP C12 or C14