|
|
Combo 101.
Combo 101 uses AFR 210 heads and a mechanical street roller cam. This 406 cu. in. engine makes 494 ft-lbs at 5000 RPM and 487 horses at 5500 RPM. The carb is too small. There are plenty of high-horse 350's that need more than a 750 carb. With 210 cc AFR heads, a mechanical roller cam with 0.525/0.543 in. of lift, and a Victor Jr. intake, the engine builder somehow thinks that this 406 beast will breathe freely with a 750. Surely an 850 would have performed better.
Not only is this engine restricted on the intake side–it also has 1 5/8 in. headers to restrict the exhaust gases. If this engine doesn't deserve at least 1 3/4 in. headers, what does? The article tells that the revs are to be kept at a minimum, and smaller headers will do this. However, these are too small. As diameter increases, cross-sectional area increases quadratically. In other words, the extra 1/8 in. in diameter increases flow area by 16%! This is an engine that could use this extra 16%.
|
|
| Displacement: |
406 cu. in. |
| Carburetor: |
Holley 750 |
| Heads: |
Air Flow Research 210, with 2.08/1.60 in. valves. |
| Intake: |
Edelbrock Victor Jr. |
| Camshaft: |
Crane mechanical street roller, with 0.525/0.543 in. of lift and 236°/244° of duration @ 0.050 in. of lift. |
| Exhaust: |
Hedman 1 5/8 in. headers with Borla XR-1 mufflers |
| Pistons: |
forged |
| Rods: |
stock |
| Crank: |
GM |
| Ignition: |
MSD 6AL |
| Comp. Ratio: |
10:1 |
|
|
| MAX HP: |
487 @ 5500 |
| MAX Torque: |
494 @ 5000 |
|
|
|
Combo 102.
Combo 102 is a GM ZZ4 350 cu. in. engine with AFR 195 heads and a Comp Cams hydraulic roller cam. With an 850 carb and 1 3/4 in. headers, this engine produces 506 HP and 436 ft-lbs of torque. This engine shows what that adequate induction and exhaust systems are imperative for more power. 3 in. mufflers could have helped a bit, though.
|
|
| Displacement: |
350 cu. in. |
| Carburetor: |
Demon 850 |
| Heads: |
Air Flow Research 195, with 2.02/1.60 in. valves |
| Intake: |
Edelbrock Victor Jr. |
| Camshaft: |
Comp Cams hydraulic roller, with 0.562/0.580 in. of lift and 248/254° of duration @ 0.050 in. of lift. |
| Exhaust: |
Hooker 1 3/4 in. headers and 2 1/2 in. Flowmaster mufflers |
| Pistons: |
GM high-silicon aluminum |
| Rods: |
GM |
| Crank: |
GM forged |
| Ignition: |
MSD 6AL |
| Comp. Ratio: |
10:1 |
|
|
| MAX HP: |
506 @ 6500 |
| MAX Torque: |
436 @ 5500 |
|
|
|
Combo 103.
Combo 103 comes from pages 36-41 of the October 2001 issue of Car Craft. This engine is a Motown 415 mule from Bill Mitchell Hardcore Racing Products, and it is very similar to Combo 92. Combo 103 makes 485 HP and 515 ft-lbs of torque with World Products MoTown heads and a cam with lift in the lower 0.500's.
|
|
| Displacement: |
415 cu. in. World Products MoTown (4.125 in. bore x 3.875 in. stroke) |
| Carburetor: |
Holley 750 with a Holley 850 base—flow is 870 cfm. |
| Heads: |
World Products MoTown 220, with 2.08/1.60 valves |
| Intake: |
World Products Sportsman dual plane |
| Camshaft: |
Crane hydraulic, with 0.516/0.525 in. of lift and 244/252° of duration @ 0.050 in. of lift. |
| Rockers: |
Manley aluminum roller, 1.5:1 |
| Headers: |
1 3/4 in. |
| Pistons: |
Wiseco-JE forged aluminum (4.185 in. bore). |
| Rods: |
Manley 4340 forged steel H-beam 6.0 in. |
| Crank: |
4130 forged steel (3.875 in. stroke). |
| Distributor: |
HEI |
| Timing: |
38° |
| Comp. Ratio: |
9.0:1 |
|
|
| MAX HP: |
485 @ 5600 and 5700 |
| MAX Torque: |
515 @ 4300 |
|
|
|
Combo 104.
Combos 104 and 105 come from pages 76-77 of the September 2001 issue of Car Craft.
Combo 104 uses the new Edelbrock E-Tec 170 (GM Vortec replacement) heads with a moderate cam to produce 400 HP and 417 ft-lbs of torque.
|
|
| Displacement: |
355 cu. in. |
| Carburetor: |
Edelbrock 750 Performer. |
| Heads: |
Edelbrock E-Tec 170, with 1.94/1.50 valves |
| Intake: |
Edelbrock RPM Air-Gap Vortec |
| Camshaft: |
Erson TQ40H hydraulic flat-tappet, with 0.471 in. of lift and 218/228° of duration @ 0.050 in. of lift. (Lift with 1.6:1 rockers is 0.503 in.) |
| Rockers: |
1.6:1 |
| Headers: |
1 3/4 in. primaries with 3 in. collectors |
| Pistons: |
stock. |
| Rods: |
stock |
| Crank: |
stock |
| Comp. Ratio: |
8.5:1 |
|
|
| MAX HP: |
400 @ 5500 |
| MAX Torque: |
417 @ 4500 |
|
|
|
Combo 105.
Combo 105 uses the new Edelbrock E-Tec 200 (GM Fast-Burn replacement) heads and the same cam as Combination 104, but the 200 cc. intake runners could use much more cam. This combination actually makes less power and torque than the previous engine with Edelbrock Vortec replacement heads.
|
|
| Displacement: |
355 cu. in. |
| Carburetor: |
Edelbrock 750 Performer. |
| Heads: |
Edelbrock E-Tec 200, with 2.02/1.60 valves |
| Intake: |
Edelbrock RPM Air-Gap Vortec |
| Camshaft: |
Erson TQ40H hydraulic flat-tappet, with 0.471 in. of lift and 218/228° of duration @ 0.050 in. of lift. (Lift with 1.6:1 rockers is 0.503 in.) |
| Rockers: |
1.6:1 |
| Headers: |
1 3/4 in. primaries with 3 in. collectors |
| Pistons: |
stock. |
| Rods: |
stock |
| Crank: |
stock |
| Comp. Ratio: |
8.6:1 |
|
|
| MAX HP: |
391 @ 5400 |
| MAX Torque: |
413 @ 4400 |
|
|
|
Combo 106.
Combos 106 and 107 come from pages 60-64 of the March 2002 issue of Chevy High Performance.
Using a 383, these combos make power just over 400 horses and torque in the 450 region. With help from a modest Crane roller cam, these combinations test World Products MoTown 220 iron and aluminum heads.
|
|
| Displacement: |
383 cu. in. |
| Carburetor: |
Holley 750 double pumper |
| Heads: |
World Products MoTown 220 iron (217 actual cc), with 2.055/1.60 valves |
| Intake: |
World Products Sportsman dual plane |
| Camshaft: |
Crane hydraulic roller, with 0.525/0.543 in. of lift and 232/240° of duration @ 0.050 in. of lift. |
| Rockers: |
Crane gold aluminum roller, 1.5:1 |
| Exhaust: |
Hedman 1 5/8 in. headers with 2 1/2 in. Borla mufflers. |
| Pistons: |
SRP forged aluminum |
| Rods: |
SCAT forged 4130 I-beam 6.0 in. |
| Crank: |
SCAT internally balanced cast-iron |
| Distributor: |
Moroso HEI with a Crane HI-6 ignition |
| Timing: |
37° |
| Comp. Ratio: |
9.9:1 |
|
|
| MAX HP: |
407 @ 5600 |
| MAX Torque: |
449 @ 4200 |
|
|
|
Combo 107.
Combo 107 uses aluminum MoTown heads instead of the iron ones. They have CNC'd chambers from World Products. These heads were tested on the flowbench, and they actually flowed less than the irons. The hardened seats had apparently distorted the metal too much, so the heads were opened until they flowed as much as the iron ones. These heads showed a 5 ft-lb improvement and a 1 horse gain.
|
|
| Displacement: |
383 cu. in. |
| Carburetor: |
Holley 750 double pumper |
| Heads: |
World Products MoTown 220 aluminum (224 actual cc), with 2.055/1.60 valves |
| Intake: |
World Products Sportsman dual plane |
| Camshaft: |
Crane hydraulic roller, with 0.525/0.543 in. of lift and 232/240° of duration @ 0.050 in. of lift. |
| Rockers: |
Crane gold aluminum roller, 1.5:1 |
| Exhaust: |
Hedman 1 5/8 in. headers with 2 1/2 in. Borla mufflers. |
| Pistons: |
SRP forged aluminum |
| Rods: |
SCAT forged 4130 I-beam 6.0 in. |
| Crank: |
SCAT internally balanced cast-iron |
| Distributor: |
Moroso HEI with a Crane HI-6 ignition |
| Timing: |
37° |
| Comp. Ratio: |
9.9:1 |
|
|
| MAX HP: |
408 @ 5600 |
| MAX Torque: |
454 @ 4200 |
|
