[stang93mustang]

Please need some input on this. I'll make it short as possible.

460 stroker motor that breaths VERY well! 1050 dominator, Victor manifold, Barry Grant 440 fuel system.

I have PSI set between 6 1/2 and 7, Motor still running rich. My question would be how low of jets could I go and be safe then start going up from there?

Any input would be greatful.

Thanks

[EagleAutosports]

Why such a large carb? It could possibly be too much for it because stepping down in jet size doesn't exactly get it out of being rich. You need to calculate the volumetric efficiency to get the proper carb size.

The formula is:
Carb CFM = cubic inches X max rpm's DIVIDED by 3456.

Since it's a 1050, it depends on which particular carb you have.
4575: 84 front and back
6464: 88 front and back
8082: 84's
8082-1: 88's
8082-2: 84's
8896: 88's
8896-1: 88's
9375: 92's
9375-1: 88's
80340: 84's
80340-1: 88's

Holley carbs are calibrated for sea level operation and an inlet air temperature of 70 degrees Fahrenheit. Once you know the correct stock jetting for your particular carb, you can determine whether you live or race at an altitude above sea level. For every 2000 foot increase in altitude, you can reduce the jet size by one size. If you had a carb which has a stock jet size of 80 and you live or race at 2000 feet above sea level, then you would use a #79 jet in the carb. Similarly, a change in the carb's inlet air temperature may require a change in the jet size from the stock calibration. Many racers go a step further by combining all of the weather variables, temperature, barometric pressure, dewpoint and humidity with the altitude of the track they are racing at to determine the "density altitude". This is a "corrected" altitude above sea level. From there they can determine whether a jet change is necessary to maintain performance or whether to change their "dial in" (if they are bracket drag racers).

[stang93mustang]

The formula is:
Carb CFM = cubic inches X max rpm's DIVIDED by 3456.

Since it's a 1050, it depends on which particular carb you have.
4575: 84 front and back
6464: 88 front and back
8082: 84's
8082-1: 88's
8082-2: 84's
8896: 88's
8896-1: 88's
9375: 92's
9375-1: 88's
80340: 84's
80340-1: 88's

Thanks for the info. A little difficult right now to understand fully but I will!

Carb is a 8896-1 and right now it does have in it 84/85's.

Plugs are still black. When we first got it running we had the fuel pressure out of this world! Brought it down to 6 1/2 - 7, got rid of the black smoke!

I for sure know that there is more to this.

I was considering going to mid 70's in jets but did not know if they were too small.

[blueracecar]

you may want to check the four corner idle screws and see where you are at idle.if it is too rich it will just load up at idle and cruising speeds and when you put your foot down it will look like a diesel.all you will need is a vac gauge and a screwdriver

[stang93mustang]

Originally Posted by blueracecar

you may want to check the four corner idle screws and see where you are at idle.if it is too rich it will just load up at idle and cruising speeds and when you put your foot down it will look like a diesel.all you will need is a vac gauge and a screwdriver

Now that you mention it, I am thinking alittle something there also for the fact that I barely have to turn the idle screw in to bring R's up @ idle.

[blueracecar]

if the idle goes up when you turn them in it means you are leaning it up.even if you dont have a vac gauge you can go around turning the screws up individually the same amount.every once in a while you will have to lower the idle speed and continue.it could be the power valve(s) if your carb has them.i dont know about dominators, i am way down on the food chain with a 650 hp

[stang93mustang]

Originally Posted by blueracecar

if the idle goes up when you turn them in it means you are leaning it up.even if you dont have a vac gauge you can go around turning the screws up individually the same amount.every once in a while you will have to lower the idle speed and continue.it could be the power valve(s) if your carb has them.i dont know about dominators, i am way down on the food chain with a 650 hp

What's your take on this?! The main idle screw at this point is not being a factor. What happens if I turn the mixture screws in (evenlly of course) until it forces the motor to use the idle screw more to idle?

[blueracecar]

i guess i dont really understand your question.you can turn your corner idle screws in evenly giving the engine just a minute every time to catch up to the adjustment.it will raise your idle speed because it is not running as rich and bogging down.so perodically you will have to lower your idle speed on the primary linkage.the best way to do it is with a vac gauge. you want to get the most vac at idle you can at the lowest rpm idle. if you watch the gauge it will continue to rise and once you reach a point it goes down you got it. back them out just a little (1/8 turn or so) and your good.it wont affect how the car runs because all you are changing is how much fuel it gets at idle.i had the same problem and needed one pass just to clear the engine.

[stang93mustang]

Okay starting to put pieces together here!

From the beginning, I turned each mixture screw 2.5 out. More than likely creating the rich scenareo right there. The fact that my idle screw is not a factor meaning it never touched the throttle bracket! When I tried to lean it out the car obviously wanted to die. I should go ahead and lean out and get it so the the idle screw is having to make the car idle. Sounds like it would make sense?!

[blueracecar]

makes sense to me.give it a shot and see what hapens,if it is still rich it could be a blown power valve(holley is known for that)

[stang93mustang]

Thanks for helping me with the questions you asked. I will be putting the motor back in today and will be starting it either later today or tomorrow.

I'll look into the power valve also. There is an elinimator kit for dominator carbs. I'll check out the advantages and disadvantages.

Thanks again,

Reese

[stang93mustang]

well, I have removed both power valves, jetted up 6 sizes on primary and secondary. Idle mixture screws are now only turned out about 1 1/4 turns at all four corners. The car is running much leaner for sure! I think it can still be leaned out more without trouble. I don't have a vacuum guage nor would I know where to measure from on a Dominator. I have no fittings for vacuum sources at all! My next question would be how much of a factor are the air bleed screws? I know these could also be changed out.