QFT 1050 - 4150 CARB

[steve cowan]

when is dyno day?

Was hoping to be done already but parts delay and lack of labour at work has led me to be working alot of hrs unfortunately.
Now I am worried about getting flooded as we have had more than 600mm (2ft) rain in 2 days and not going to let up for at least 24-36 hrs.

[Fatman]

good luck with the rain mate.

[steve cowan]

So I received my new carb.
The one thing I recommend for anyone is to buy pin gauges,completely disassemble and check everything.
As with most things there are a couple things that need a tweak.
These are not a custom carb that's for sure.
I also got a new set of 1 3/4" TRI - Y headers to test.
I will be modifying the stock collector 2 1/4" and fitting up a 3" dia 19" long collector as per pipemax
Also welding AFR bungs.

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[cpmotors]

I've used 4-5 of the Q1050AN on pump gas 500ci 650-700hp range builds with good results, and have ran MS109 through them without making changes just to see what they pick up in power.
The first thing I do on all of them is to move the IFR back down into the lower position so they idle and cruise better.

[prairiehotrodder]

Hi Steve, what was the layout of the emulsion jetting if you don't mind me asking ?
from the factory .

[steve cowan]

Hi Steve, what was the layout of the emulsion jetting if you don't mind me asking ?
from the factory .

Brian,
28,blocked, 28,blocked, 32
Primary and secondary checked with pin gauge

[steve cowan]

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.

I have had a 950hp for 10 years or so which I got to run pretty well, fitting transfer slot jets in the main body,moving IFR to the lower position in the metering block help alot with these carbs.
I have had good luck with 1:1 throttle and using power valves front and rear especially in a street type deal.
I think the 950hp carb can be made to work well on a SBC up to 530hp or so.
I bought a new 850hp body that I fitted to 950hp base plate,drilled and taped for transfer slot jets,I am using a 3 hole metering block with 19"- blocked - 19"
No power valves,160" down leg boosters.have not run this carb yet so initially fire up with my 830 hp annular carb.
The dyno operator is excellent with holley carbs so if any issues we can isolate quickly.
The exhaust port on those heads came up good and it's taken a few goes over last 5 years lol.
I remember when I started to learn when I got flow bench etc it all kicked my a$$.
My 1 5/8" tri - y headers I modified and port matched really well but the flange area is way smaller than my 1 3/4" tri- y and 4 into 1 headers so I am thinking of some adapter plates to fit.
When I test a exhaust port on the bench I try not to look at the number,for me it is the relationship between throat size/ application and flange size at the header.then work what is in between to get the desired CSA including port bias on some cylinders.
Early on I tried port matching Exhaust port to headers that was a mistake, in a street car deal we are limited to proper size headers usually and have to compromise.

[steve cowan]

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

Brian,
Can you remember what fuel pressure you guys ran?
If I know my fuel system has the flow capacity for the application I only run 3.5 - 4 psi with the 0.130" needle and seat,
The QFT 1050 carbs use a 0.130" needle and seat

[HQM383]

Hi Steve, what was the layout of the emulsion jetting if you don't mind me asking ?
from the factory .

Brian,
28,blocked, 28,blocked, 32
Primary and secondary checked with pin gauge

And the IFR and air bleeds?

I’m really keen to see your dyno results with your different carbs and spacers and results down the qtr with each if that’s what you intend to do. Curious on the correlation between dyno and track with different size carbs.

[steve cowan]

Hi Steve, what was the layout of the emulsion jetting if you don't mind me asking ?
from the factory .

Brian,
28,blocked, 28,blocked, 32
Primary and secondary checked with pin gauge

And the IFR and air bleeds?

I’m really keen to see your dyno results with your different carbs and spacers and results down the qtr with each if that’s what you intend to do. Curious on the correlation between dyno and track with different size carbs.

On the 1050 the IFR are 0.042"in the top position.

Airbleeds 70 - 28 font and back.
A couple of things I found were the primary PVRC jets were drilled on a silly angle.
The secondary butterflies would not seat due to adjustment screw getting caught on main body hence my comment that every new carb should be disassembled and inspected.
They say these carbs are wet flow tested and engine testing prior to shipping but I doubt that.
As far as testing-
Yes very exciting and time consuming buts that's the enjoyment I guess.
I have talked to some guys who dyno and race and the say it can go either way with carbs / spacers etc some make good power on the dyno but won't have gearshift recovery on the track and vice versa.
I can see where converter/ gearing plays a big part.
Initially I have converter covered 8" 5600 stall that works well for my weight, gearing I will have to play with.
It will depend if engine hangs on after peak so I can run a lower rear gear and turn rpm.
Streetability will start to go out the window if I go to a 4.56 rear gear but that's ok.

[Fatman]

Whats the venturi size on the 1050?

[steve cowan]

Whats the venturi size on the 1050?

1.57" x 1.75" measured

[Arthur]

You are very methodical and disciplined in documenting against "internet data" - just understand that the Dyno numbers by and large will not translate to the "Best ET/MPH run" - by a large factor.
If this is your test against the rest .. so to speak .. Enjoy.

[steve cowan]

You are very methodical and disciplined in documenting against "internet data" - just understand that the Dyno numbers by and large will not translate to the "Best ET/MPH run" - by a large factor.
If this is your test against the rest .. so to speak .. Enjoy.

Arthur,
I always appreciate your feedback as you make me stop and think,I like that.
People might laugh but I actually like using the moroso speed calculator as a bench mark and I understand what you are saying about dyno # and track results as I have seen those discussions before.i have to be very careful talking about dyno this and dyno that as I have no clue ...

[prairiehotrodder]

Did the emulsion well even have jets in all the holes ? Or were the holes empty and the hole was just drilled through to the size you listed ? And the only actuall jets were blanks ? Also you list 5 spots but there are only 4. What am i missing ?