dead miss new single plane intake carb an ignition

[pontiacgp]

are you people for reals look dude the carb is not to big. turn the set screw all the way in then turn out 1 1/2 out each and that should be good

the carb is too big .....it's not a guessing game as far as what an engine needs....all 350's are the same no matter if you have 250 hp or 500 hp....and those adjustment screw are just the idle mixture screws and have nothing to do with the carb once it's past the idling circuit..

here's the equations that I posted above.....how do you figure the carb isn't too big?

here`s the equation to find out what carb is right...(cid * Rpm)/ 2(1728) * Ve= CFM needed..

355x6000 / 3456 x 100% = 616.31

 

[sickolds]

i have a sbc 383 with 750 vac sec and it fuking fly's and has no flat spots and wy do performance cars use 750??????????????

 

[sickolds]

mbo 2.
Combo 2 has a little more compression, which could account for a little bit of power gain, but the cam with longer duration is what really raises the power. I am sure that the torque does not increase too much, and it may actually decrease. The carb upgrade might have added power, but the 600 cfm carb could have easily produced this much power.

Displacement: 350 cu. in.
Carburetor: modified 750 cfm
Heads: World Products Sportsman II
Intake: Dart II Sportsman dual plane
Camshaft: 268° hydraulic, (probably the Comp Cams Xtreme Energy 268°, with 268/280° of duration, 224/230° of duration @ 0.050 in. of lift, and 0.477/0.480 in. of lift.)
Comp. Ratio: 9.5:1
MAX HP: 375 @ 6000
Combo 3.
Combo 3 has even more compression than the previous combos, which probably adds some power. The combustion chambers are cleaned up some, and an even more aggressive cam is used on this engine. If the camshaft is the Xtreme Energy grind, the torque is beginning to have some trouble with this amount of duration.

Displacement: 350 cu. in.
Carburetor: modified 750 cfm
Heads: World Products Sportsman II, bowl blended
Intake: Dart II Sportsman dual plane
Camshaft: 274° hydraulic, (probably the Comp Cams Xtreme Energy 274°, with 274/286° of duration, 230/236° of duration @ 0.050 in. of lift, and 0.487/0.490 in. of lift.)
Comp. Ratio: 9.8:1
MAX HP: 430 @ 6000
Combo 4.
Combos 4-7 comes from page 39 of the February 1989 issue of Hot Rod Magazine. All four combos use the 383 cu. in. engine with rebuilt GM heads and Holley 750 double pumper. These combos show the difference between some intakes and heads.

Combo 4 uses an Edelbrock Performer intake and a 280° cam. The power and torque numbers are pretty good.

Displacement: 383 cu. in.
Carburetor: Holley 750 double pumper
Heads: GM #441 castings, 76cc chambers, 2.02/1.60 in. valves, pocket ported
Intake: Edelbrock Performer
Camshaft: Comp Cams 280° Magnum hydraulic, with 280/280° of duration, 230/230° of duration @ 0.050 in. lift, and 0.480/0.480 in. lift
Rockers: 1.5:1
Headers: 1 5/8 in. street
Pistons: TRW forged
Rods: 5.565 in.
Crank: cast
Comp. Ratio: 9.3:1
MAX HP: 382 @ 5300
MAX Torque: 400 @ 4500
Combo 5.
Combo 5 keeps the Performer intake from Combo 4, but a 292° cam is used. This camshaft duration increase drives the power up 17 HP, and the torque stays about the same. It is suprising that a cam with this much duration does not drop the torque level.

Displacement: 383 cu. in.
Carburetor: Holley 750 double pumper
Heads: GM #441 castings, 76cc chambers, 2.02/1.60 in. valves, pocket ported
Intake: Edelbrock Performer
Camshaft: Comp Cams 292° Magnum hydraulic, with 292/292° of duration, 244/244° of duration @ 0.050 in. lift, and 0.501/0.501 in. lift
Rockers: 1.5:1
Headers: 1 5/8 in. street
Pistons: TRW forged
Rods: 5.565 in.
Crank: cast
Comp. Ratio: 9.3:1
MAX HP: 399 @ 5700
MAX Torque: 399 @ 5000 and 5500
Combo 6.
Combo 6 goes back to the 280° camshaft, but an Edelbrock Victor Jr. intake is used instead. This combination produces 17 more HP and a little more torque. Even though the Victor Jr. intake has been billed a high-RPM-only intake, this comparison shows that the intake produced more low-end torque than the Performer. Victor Jr.'s are becoming popular intakes as more car guys realize just how streetable they are.

Displacement: 383 cu. in.
Carburetor: Holley 750 double pumper
Heads: GM #441 castings, 76cc chambers, 2.02/1.60 in. valves, pocket ported
Intake: Edelbrock Victor Jr.
Camshaft: Comp Cams 280° Magnum hydraulic, with 280/280° of duration, 230/230° of duration @ 0.050 in. lift,and 0.480/0.480 in. lift
Rockers: 1.5:1
Headers: 1 5/8 in. street
Pistons: TRW forged
Rods: 5.565 in.
Crank: cast
Comp. Ratio: 9.3:1
MAX HP: 400 @ 5700
MAX Torque: 403 @ 4500 and 5000
Combo 7.
Combo 7 uses the Victor Jr. intake with the longer duration cam. The result is over 420 HP and a torque level still over 400 ft-lbs.

Displacement: 383 cu. in.
Carburetor: Holley 750 double pumper
Heads: GM #441 castings, 76cc chambers, 2.02/1.60 in. valves, pocket ported
Intake: Edelbrock Victor Jr.
Camshaft: Comp Cams 292° Magnum hydraulic, with 292/292° of duration, 244/244° of duration @ 0.050 in. lift, and 0.501/0.501 in. lift
Rockers: 1.5:1
Headers: 1 5/8 in. street
Pistons: TRW forged
Rods: 5.565 in.
Crank: cast
Comp. Ratio: 9.3:1
MAX HP: Over 420
MAX Torque: Over 400
Combo 8.
Combos 8-10 come from the Trick Flow Specialties web site. All three combinations use the same 383 cu. in. engine with a moderate roller camshaft and 10:1 compression. The next three combos vary cylinder heads.

Combo 8 uses the Trick Flow 23° Street heads. These heads are not the Twisted Wedge heads for which Trick Flow became known. Instead, these are direct bolt-on heads, and are marketed to compete with $750/pair to $1,000/pair heads such as the World Products Sportsman II, Dart Iron Eagle, Edelbrock Performer RPM, Holley Systemax, etc. With some help from the roller cam, this engine makes 460 HP and 451 ft-lbs of torque.

Displacement: 383 cu. in.
Carburetor: Holley 750 double pumper
Heads: Trick Flow 23° Street
Intake: Edelbrock Victor Jr.
Camshaft: Comp Cams hydraulic roller, with 230/236° of duration @ 0.050 in. lift, and 0.510/0.520 in. lift
Rockers: Trick Flow roller, 1.5:1
Headers: 1 3/4 in. primaries, with 3 in. exhaust and Flowmaster mufflers
Pistons: KB hypereutectic, 12 cc dish
Rods: Trick Flow forged, 5.7 in.
Crank: Trick Flow forged
Distributor: MSD Billet with 6AL ignition
Comp. Ratio: 10.0:1
MAX HP: 460 @ 6000
MAX Torque: 451 @ 5000 :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!: :!:

 

[sickolds]

Combo 13.
Combo 13 is close to Combo 12, but it uses the 190cc Street heads instead of the 195cc version. These heads are supposed to be better suited to the smaller 350 cu. in. small block. Notice that the 270° Magnum is very close to the cam in Combo 12. Perhaps the reason for the power and torque increase is the larger 750 cfm double pumper and extra half-point of compression.

Displacement: 355 cu. in.
Carburetor: Holley 750 double pumper
Heads: Air Flow Research 190cc Street
Intake: Air Flow Research FloPower RPM
Camshaft: Comp Cams 270° Magnum hydraulic, with 270° of duration, 224° of duration @ 0.050 in. lift, and 0.470 in. lift
Headers: 1 5/8 in.
Distributor: MSD
Timing: 34°
Comp. Ratio: 9.5:1
MAX HP: 430 @ 5000
MAX Torque: 470 @ 4500
Combo 14.
Combo 14 uses the same parts as Combo 13, but a hydraulic roller camshaft is used. The result is 20 more HP with the same amount of torque.

Displacement: 355 cu. in.
Carburetor: Holley 750 double pumper
Heads: Air Flow Research 190cc Street
Intake: Air Flow Research FloPower RPM
Camshaft: Comp Cams hydraulic roller, with 230/236° of duration @ 0.050 in. lift, and 0.510/0.520 in. lift
Headers: 1 5/8 in.
Distributor: MSD
Timing: 36°
Comp. Ratio: 9.5:1
MAX HP: 450 @ 5500
MAX Torque: 470 @ 4500
Combo 15.
Combo 15 uses a 383 cu. in. engine with 9.5:1 compression and a 750 double pumper. With a 280° hydraulic camshaft and the AFR 190cc Street heads, this combination makes an awesome 471 HP and an incredible 515 ft-lbs of torque. This is the ultimate street engine.

Displacement: 383 cu. in.
Carburetor: Holley 750 double pumper
Heads: Air Flow Research 190cc Street
Intake: Air Flow Research FloPower RPM
Camshaft: Comp Cams 280° Magnum hydraulic, with 280° of duration, 230° of duration @ 0.050 in. lift, and 0.480 in. lift
Headers: 1 3/4 in.
Distributor: MSD
Timing: 34°
Comp. Ratio: 9.5:1
MAX HP: 471 @ 5500
MAX Torque: 515 @ 4500
Combo 16.
Combo 16 uses the same parts as Combo 15, but with a hydraulic roller camshaft. The awesome 500 HP/ 500 ft-lb mark is almost reached. This is an awesome street engine also.

Displacement: 383 cu. in.
Carburetor: Holley 750 double pumper
Heads: Air Flow Research 190cc Street
Intake: Air Flow Research FloPower RPM
Camshaft: Comp Cams hydraulic roller, with 230/236° of duration @ 0.050 in. lift, and 0.510/0.520 in. lift
Headers: 1 3/4 in.
Distributor: MSD
Timing: 36°
Comp. Ratio: 9.5:1
MAX HP: 491 @ 5500
MAX Torque: 501 @ 4000
:?: :?: :?: :?: :?: :?: :?: :?: :!: :!: :!: :!: :!: :!: :!: :!:

 

[sickolds]

so do those combos have carbs that are to big? :?: :?: :?: :?: :?: :?: :?: :?: :?: :?: :?: :?: :?: well :?: :?: :?: :?: :?: :?: :?:

 

[pontiacgp]

so what are your times with the 750 carb compared to a 650 or 600?

the calculations for your 383 is 665 at 6000 rpm with 100% volumetric efficiency ...more realist for the volumetric efficiency is probably around 80 - 90% which requires a carb of almost 600 at 6000 rpm...

these numbers are not made up, it's a physical equation and people use them so they don't have to guess what their car needs

 

[bigbrute]

mid 15 now 600 holley not sure with the 750 it still hass a stock rear gear an one wheel peal so im not to up set all it did was spin..... my old man herd it breaking up a lil on the big end an about 1/8 i noticed a chang on my time slips i plan on going with a 3.90 4.10 or 4.56 an mini spoll for now

 

[sickolds]

dude the second part of that carb does not open all the way to give it true 750 the second part opens on vac demand
(CFM and Carburetors:
Carburetors are rated by CFM (cubic feet per minute) capacity. 4V carburetors are rated at 1.5 inches (Hg) of pressure drop (manifold vacuum) and 2V carburetors at 3 inches (Hg). Rule: For maximum performance, select a carburetor that is rated higher than the engine CFM requirement. Use 110% to 130% higher on single-plane manifolds. Example: If the engine needs 590 CFM, select a carburetor rated in the range of 650 to 770 CFM for a single-plane manifold. A 750 would be right. An 850 probably would cause driveability problems at lower RPM. A 1050 probably would cause actual loss of HP below 4500 RPM. For dual-plane manifolds use 120% to 150% higher.).....................

 

[sickolds]

so???????????

 

[sickolds]

well????????