QFT 1050 - 4150 CARB

[steve cowan]

I just purchased a new QFT 4150 - 1050 carb,I like the idea of dual carb flange size and have 2 x 4500 adapters to test.
Looking for any feedback or information if emulsion will need changing prior to going to dyno,
I have 2 other carbs to test as well - 850 hp with 0.160" down leg boosters I fitted and a 830 hp annular boosters.
Engine to be dynoed -
383 sbc
Dart block 11.45 comp
Scat crank and rods,JE short skirt coated pistons 1.2mm , 1.5mm ,3mm light oil ring at 4lbs running GZ vac pump that pulled 15" on old combo.
Comp custom roller
Dart iron heads 186 cc with avg CSA of 2.15" - 2.2"
1.94" - 1.5 " valves 50 deg seats flow 278 @ 700" , 230 @ 700" on the Exh
Valve lift 670" - 600" after lash
Ported 300-25 with plenty of spacers to test
Will be run on MS 109
Testing tri - y headers and 4 into 1 headers.
I hope for 1.3 ft/ lbs per cube more would be nice but this is my first engine dyno for myself.
Really looking at carb feedback as engine is assembled.
Thanks in advance

[cgarb]

That has one hell of an exhaust port for a 1.50" valve. Will be an interesting test for sure. Do you have a 950 to try on it? I like those carbs. Seems like they run well on most everything I've put one on.

[prairiehotrodder]

a friend has this carb on a 423 SBC race engine. We have found its stock calibration to be excessively rich. The emulsion well jetting was different from what QFT said it was supposed to be as well. Not happy with it.
Brian

[PRH]

I’ve only used one of the Q-1050’s....... the downleg version.
It was on a street/strip 572 Mopar.

It was pretty good ootb on that motor...... we might have changed the jets one size.

I can see where it might not be great match for something with way less cubes.

E51482A3-3A04-46F4-BDB4-8C8F37A3EE06.jpeg

That pull is with 85/91 jets. No calibration changes to anything else.

[1980RS]

My old Holley 1000HP with A/D boosters made just north of 800hp on a good BBC a couple of years ago and after another guy (who I sold it too) had his tuner do more work on the metering blocks his engine made 845hp. He loves it.

[Elroy]

Itll make 1.3 or better on ms109 for sure.

[Fatman]

No help on the carb here but interesting build.

Have you got a thread on your build? I'd like to check it out.

[steve cowan]

No help on the carb here but interesting build.

Have you got a thread on your build? I'd like to check it out.

No not yet.
I want to dyno then run it in my car to verify my results.

[Fatman]

No help on the carb here but interesting build.

Have you got a thread on your build? I'd like to check it out.

No not yet.
I want to dyno then run it in my car to verify my results.

Any particular Hp numbers or ETs that you are aiming for?

[steve cowan]

No help on the carb here but interesting build.

Have you got a thread on your build? I'd like to check it out.

No not yet.
I want to dyno then run it in my car to verify my results.

Any particular Hp numbers or ETs that you are aiming for?

Engine pro sim says 580 hp but I am a bit Leary on that.
I want peak at 6500 but I might be under valved for the cubes .
I have a set of SHP 180 out to 205cc that I ported and valve job myself which I believe will respond well but that's for next year.
My HQ style side ute weighs 3650 with me and runs not bad for hp to ET comparisons.
If this combo makes 560 ish and car runs 10.6 - 70s I will be happy.
If ET - MPH don't line up with dyno numbers I will tune the rest of the car to get that comparisons in line.
Reality for me is just trying to learn and be happy as I do most everything myself.

[Fatman]

What is your min area through the pushrod pinch?

[steve cowan]

2.10 with radius factored in
Ground out pinch and patched with Belzone ,raised roof as high as possible.
These heads started as 165cc
So getting thin in some areas now.
From memory 320 ft/ sec @ 28" avg at the pinch,checked at 3 positions.

[BobbyB]

2.10 with radius factored in
Ground out pinch and patched with Belzone ,raised roof as high as possible.
These heads started as 165cc
So getting thin in some areas now.
From memory 320 ft/ sec @ 28" avg at the pinch,checked at 3 positions.

What was the CSA before porting?

[steve cowan]

At the pinch 1.6"
As cast flowed
210 @ 0.500" @ 28 "
138 @ 0.500"@ 28"

[Fatman]

when is dyno day?