Carb rec

[bearcat]

I have a 550HP 468 with an aggressive cam and 13:1 pistons. Stock heads knock it down a little. I was running a 1050 dominator, but too much (too rich) for daily street driving. Was awesome when opened up.

I'm looking for a carb rec for my application. Not going to be track driven, but I have wide open roads all over the place.

I was thinking 850 with vacuum secondaries.

Please chime in with ideas. I don't want to smell like raw fuel anymore while driving the car.

Thanks,

[GregWeld]

Bear ===


There is MATH for that:

Take your CUBIC INCHES X's MAX RPM divide by 3456 X's the V/E of .85


So in your case

468 X's 6000 = 2,808,000
2,808,000 div by 3456 = 812.5
812.5 X's .85 = 690 CFM

That is making some assumptions - such as max rpm - and using a relatively conservative assumption of engine volumetric efficiency (85%)

I'd probably be running an 850 CFM and mess with the jetting til it was right.

Math works out to an 800 CFM if you raise the RPMS to 6500 and use .90 for VE....

Too big is worse than slightly small IMHO. Higher airflow will help your idle - and throttle response and you won't notice the 10 HP at the top end you might lose. My bet is that with the right carb - your torque would jump up and your car will be and feel far faster.

[Vegas69]

If your engine is set up correctly now, it won't respond well to your plans. Your trying to make a one trick pony that likes to run take a walk in a jail cell. I'd change the cam, pistons, intake, carb, converter, etc.

[OLDFLM]

FWIW My 440cid Pontiac made:

601hp/551tq with a 1050 Dominator

590hp/550tq with a 950HP and a 1" spacer

576hp/541tq with a PRO Systems 820 cfm 4150 carb and no spacer FTW!

HTH

V/R,
Ty

[GregWeld]

Originally Posted by OLDFLM

FWIW My 440cid Pontiac made:

601hp/551tq with a 1050 Dominator

590hp/550tq with a 950HP and a 1" spacer

576hp/541tq with a PRO Systems 820 cfm 4150 carb and no spacer FTW!

HTH

V/R,
Ty

NUMBERS, don't tell the whole story. He's asking for drivability. Having done this for awhile.... My bet is the 820 would DRIVE far better than the 1050 Dominator. Throttle response would be improved etc.

What I can't figure out is the 13:1 comp ratio and "street" driving...

[bearcat]

Originally Posted by GregWeld

NUMBERS, don't tell the whole story. He's asking for drivability. Having done this for awhile.... My bet is the 820 would DRIVE far better than the 1050 Dominator. Throttle response would be improved etc.

What I can't figure out is the 13:1 comp ratio and "street" driving...

I'm going to build up another engine when I absorb the cost of this project. Car is driving. I don't want to tear it apart at this point in time. Maybe over the summer. (I live in PHX)

[bearcat]

oh btw. Went with quick fuel 850. Badass set up now.