15 engines dyno tested
http://www.carcraft.com/eventcoverage/1 ... ar_setups/
stealthram base
heres a rather interesting test of a vortec head SBC with a STEALTH RAM and roller cam, that worked out rather well, but keep in mind a HOLLEY STEALTHRAM set up to fit VORTEC HEADS ,and a ROLLER CAM and mildly ported vortec heads will significantly out perform the STOCK TPI COMPONENTS
http://www.highperformancepontiac.com/t ... ck_engine/
The Plan
HPP's protocol for this story is simple: Test the engine with a stock-style TPI and aftermarket EFI cam profile, and then switch the manifold/induction system. In total, four different induction systems are analyzed, however, the camshaft that works well with the stock-length TPI manifold isn't optimized for the other intake manifolds with a much shorter runner. The manifold runner length varies from approximately 5 to 8 inches in total. This value is independent of the runner in the cylinder head. A Vortec cylinder-head runner is approximately 6 inches long. The total intake track length of the different manifolds varies from approximately 11.75 to 14 inches in comparison to the stock TPI's 24 inches.
For an engine to make the most power, the intake valve timing needs to be matched to the tuning (resonant) characteristics of the intake manifold. The runner length is the dominant effect in the equation, while the cross-section does play a much less important role. Due to this, all of the intake manifolds were tested with the camshaft used with the long runner TPI, and then retested with a more applicable grind that takes advantage of the shorter induction path. Since the second cam won't work well with the stock-style TPI, that system wasn't tested with it.
The Cams
For our exercise, the TPI or long-runner cam is identified as Cam No. 1. It's from Comp Cams, PN 08-304-8. The duration is stated as 210/220 degrees at 0.050-inch lift, intake and exhaust, respectively. Cam-lobe lift is 0.332-inch intake and 0.342-inch on the exhaust, and the lobe centerline is 114 degrees. The cam was installed at an intake lobe center of 110.5 degrees.
The short runner Cam No. 2 was custom-ground by Bullet Cams to Bob Wise's own specifications. Race Krafters has extensive engine-building experience and often employs its own cam profiles. This bump stick has 226/234 degrees of duration at 0.050-inch lift. Cam-lobe lift is 0.353/0.355-inch,564/0.532 lift at the valves with the 1.6:1 roller rocker, the centerline is 112 degrees, and the cam was installed at 108 degrees.
Dyno Test Tpi Engine Holley Four Barrel The contrast in throttle-body design is best represented by the 75mm Ram Jet single butter
Harland-Sharp full roller rockers were fitted with a 1.6:1 ratio on the intake valves and 1.5:1 on the exhaust valves. This produced a net lift of 0.531/0.513 on Cam No. 1 and 0.564/0.532 on Cam No. 2. The cylinder heads were upgraded to 2.02/1.60-inch valves over the stock 1.94/1.50 design.
The Manifolds
Stock-length TPI: Due to the high flow capacity of the Vortec cylinder heads, a stock GM TPI isn't used. Instead, ACCEL large-tube runners and a High-Flo Edelbrock Vortec manifold base is employed with an ACCEL twin 58mm throttle body (stock is 48mm). The plenum is a stock GM piece ported by RaceKrafters. This induction system is the same length as the stock GM design but has larger passages to promote better airflow. (This is the only setup with EGR provisions, so it will be the only one capable of passing smog inspections in smog-test states.)
Holley single-plane: Similar to a single-plane carburetor manifold, this design allows the use of a 750-cfm four-barrel air door, which is basically a carburetor throttle body. This manifold is the closest in operating characteristics to a carburetor system than any of the others. The end runners are 8 inches long, while the center path is 7.5 inches.
Holley Stealth Ram: This one has an upright plenum and is similar to the system GM used on the factory LT1 EFI engine, but the Holley has a 7-inch long-runner, while the LT1 is nearer 4 inches. A Holley twin 58mm throttle body is used.
GM Ram Jet: The GM Performance Parts manifold is a short-runner design with a more direct flow path to the cylinder head than the TPI. It's known for good flow characteristics and the ability to support higher engine speeds than the stock TPI. This manifold features a 5.75-inch long-runner. The throttle body is an LS1-style with a single 75mm butterfly.
BTW theres two common vortec intake manifold gaskets, these vortec heads have taller ports than the standard 23 degree first gen SBC heads
The Fel Pro 1255 is .120 thick
The GM 89017465 is .060 thick
DYNO RUNS WITH CAM NO. 2
Holley Single-Plane GM Ram Jet Holley Stealth Ram
RPM TQ HP RPM TQ HP RPM TQ HP
2,900 418.6 232.3 2,900 422.6 232.3 2,900 430.6 238.9
3,000 417.9 238.7 3,000 421.5 240.7 3,000 430.6 246.0
3,100 420.2 248.0 3,100 422.0 249.1 3,100 430.1 253.9
3,200 419.1 255.4 3,200 421.8 257.0 3,200 429.6 261.7
3,300 417.6 262.4 3,300 419.4 263.5 3,300 427.3 268.5
3,400 415.6 269.0 3,400 417.4 270.2 3,400 424.4 274.7
3,500 414.6 276.3 3,500 415.1 276.6 3,500 419.7 279.7
3,600 413.4 283.3 3,600 412.9 283.0 3,600 415.8 285.0
3,700 414.0 291.7 3,700 409.7 288.6 3,700 415.0 292.4
3,800 415.2 300.4 3,800 414.1 299.6 3,800 420.6 304.3
3,900 419.4 311.5 3,900 420.1 311.9 3,900 429.1 318.6
4,000 427.0 325.2 4,000 428.8 326.6 4,000 433.2 329.9
4,100 435.6 340.1 4,100 433.9 338.7 4,100 440.5 343.9
4,200 441.7 353.2 4,200 435.7 348.4 4,200 445.3 356.1
4,300 441.0 361.1 4,300 432.9 354.4 4,300 445.8 365.0
4,400 439.3 368.1 4,400 432.5 362.4 4,400 447.0 374.5
4,500 439.4 376.5 4,500 433.0 371.0 4,500 449.7 385.3
4,600 441.6 386.8 4,600 433.5 379.7 4,600 452.4 396.3
4,700 443.2 396.6 4,700 437.5 391.5 4,700 455.3 407.5
4,800 445.5 407.2 4,800 440.1 402.3 4,800 458.2 418.8
4,900 448.1 418.1 4,900 444.5 414.7 4,900 460.1 429.2
5,000 451.8 430.1 5,000 448.3 426.8 5,000 459.9 437.8
5,100 452.7 439.6 5,100 450.8 437.7 5,100 459.4 446.1
5,200 452.2 447.8 5,200 453.1 448.6 5,200 458.4 453.9
5,300 453.0 457.2 5,300 452.0 456.1 5,300 458.2 462.4
5,400 450.4 463.1 5,400 448.2 460.9 5,400 454.8 467.7
5,500 447.5 468.6 5,500 447.7 468.8 5,500 452.7 474.1
5,600 442.9 472.3 5,600 444.3 473.7 5,600 448.8 478.5
5,700 439.0 476.5 5,700 440.5 478.1 5,700 446.0 484.0
5,800 433.6 478.8 5,800 435.7 481.2 5,800 439.0 484.9
5,900 426.2 478.8 5,900 428.7 481.5 5,900 431.5 484.7
6,000 419.4 479.1 6,000 421.7 482.7 6,000 422.9 483.2
6,100 409.3 475.8 6,100 412.4 478.7 6,100 414.6 477.8
PART NUMBERS
Company Part No. Item
Comp Cams 08-304-8 Cam No. 1 hydraulic roller
Bullet Cams Custom Cam No. 2 hydraulic roller
Edelbrock/Vortech 3817 High-Flo manifold base
FAST 301000 XFI programmable ECU
GM Performance Parts 12489371 Ram Jet 350 intake manifold
GM Performance Parts 17096144 Ram Jet 350 58mm throttle body
GM Performance Parts 12489371 Ram Jet 350 fuel rails
Holley 9901-107 Standard single-plane, multi-port, EFI,
aluminum intake manifold for Vortec heads
Holley 9900-171 1,000-cfm billet-aluminum four-barrel throttle body
Holley 9900-172 Standard single-plane, multi-port, EFI-intake fuel-rail kit
Holley 7542 Stealth Ram Vortec-head satin intake
Holley 534-186 Stealth Ram fuel-rail kit with adj. reg.
Holley 112-503 2x58mm throttle body
ACCEL *NA Large-tube runner
ACCEL *NA 58mm throttle body
*ACCEL has discontinued these parts, but they can still be found on the used market.
SLP, Edelbrock, and Arizona Speed make runners,and BBK makes a throttle body.
Intake Track Comparison With Traditional Pontiac
For a comparison to a traditional Pontiac intake track, we spoke with Jim Taylor Engine Service. Since Jim has a treasure trove of Pontiac parts at his fingertips, he was able to provide an approximate value for the induction-system length. His measurements were taken with a piece of welding wire that was first placed along the roof, and then the floor of the port. The values are added together and divided by 2 for an average.
A cast-iron factory Q-jet manifold runner falls between 8.0 and 9.5 inches. Cylinder No. 5 is the longest at 9.5 inches, while No. 8 is the shortest at 8 inches. A Holley Street Dominator intake has runner lengths that vary between 8 and 9 inches, while an Edelbrock Victor Jr. comes in with 8.5 and 9.0 inches. When the popular 6X cylinder-head runner was measured using the same method, the roof came in at 5.75 inches and the floor at 4.0 inches. The Ram Air IV cylinder head proved to have a floor length of 4 inches and a roof of 6 inches. The approximate intake-port runner length is 4.875 inches for the 6X and 5.0 inches for the Ram Air IV casting.
Using this data, a Pontiac with a set of 6X cylinder heads and a production intake manifold has an approximate mean total intake track length of 13.625 inches, or just about one half of the TPI system distance. -R.B.
http://www.carcraft.com/eventcoverage/1 ... ar_setups/
stealthram base
heres a rather interesting test of a vortec head SBC with a STEALTH RAM and roller cam, that worked out rather well, but keep in mind a HOLLEY STEALTHRAM set up to fit VORTEC HEADS ,and a ROLLER CAM and mildly ported vortec heads will significantly out perform the STOCK TPI COMPONENTS
http://www.highperformancepontiac.com/t ... ck_engine/
The Plan
HPP's protocol for this story is simple: Test the engine with a stock-style TPI and aftermarket EFI cam profile, and then switch the manifold/induction system. In total, four different induction systems are analyzed, however, the camshaft that works well with the stock-length TPI manifold isn't optimized for the other intake manifolds with a much shorter runner. The manifold runner length varies from approximately 5 to 8 inches in total. This value is independent of the runner in the cylinder head. A Vortec cylinder-head runner is approximately 6 inches long. The total intake track length of the different manifolds varies from approximately 11.75 to 14 inches in comparison to the stock TPI's 24 inches.
For an engine to make the most power, the intake valve timing needs to be matched to the tuning (resonant) characteristics of the intake manifold. The runner length is the dominant effect in the equation, while the cross-section does play a much less important role. Due to this, all of the intake manifolds were tested with the camshaft used with the long runner TPI, and then retested with a more applicable grind that takes advantage of the shorter induction path. Since the second cam won't work well with the stock-style TPI, that system wasn't tested with it.
The Cams
For our exercise, the TPI or long-runner cam is identified as Cam No. 1. It's from Comp Cams, PN 08-304-8. The duration is stated as 210/220 degrees at 0.050-inch lift, intake and exhaust, respectively. Cam-lobe lift is 0.332-inch intake and 0.342-inch on the exhaust, and the lobe centerline is 114 degrees. The cam was installed at an intake lobe center of 110.5 degrees.
The short runner Cam No. 2 was custom-ground by Bullet Cams to Bob Wise's own specifications. Race Krafters has extensive engine-building experience and often employs its own cam profiles. This bump stick has 226/234 degrees of duration at 0.050-inch lift. Cam-lobe lift is 0.353/0.355-inch,564/0.532 lift at the valves with the 1.6:1 roller rocker, the centerline is 112 degrees, and the cam was installed at 108 degrees.
Dyno Test Tpi Engine Holley Four Barrel The contrast in throttle-body design is best represented by the 75mm Ram Jet single butter
Harland-Sharp full roller rockers were fitted with a 1.6:1 ratio on the intake valves and 1.5:1 on the exhaust valves. This produced a net lift of 0.531/0.513 on Cam No. 1 and 0.564/0.532 on Cam No. 2. The cylinder heads were upgraded to 2.02/1.60-inch valves over the stock 1.94/1.50 design.
The Manifolds
Stock-length TPI: Due to the high flow capacity of the Vortec cylinder heads, a stock GM TPI isn't used. Instead, ACCEL large-tube runners and a High-Flo Edelbrock Vortec manifold base is employed with an ACCEL twin 58mm throttle body (stock is 48mm). The plenum is a stock GM piece ported by RaceKrafters. This induction system is the same length as the stock GM design but has larger passages to promote better airflow. (This is the only setup with EGR provisions, so it will be the only one capable of passing smog inspections in smog-test states.)
Holley single-plane: Similar to a single-plane carburetor manifold, this design allows the use of a 750-cfm four-barrel air door, which is basically a carburetor throttle body. This manifold is the closest in operating characteristics to a carburetor system than any of the others. The end runners are 8 inches long, while the center path is 7.5 inches.
Holley Stealth Ram: This one has an upright plenum and is similar to the system GM used on the factory LT1 EFI engine, but the Holley has a 7-inch long-runner, while the LT1 is nearer 4 inches. A Holley twin 58mm throttle body is used.
GM Ram Jet: The GM Performance Parts manifold is a short-runner design with a more direct flow path to the cylinder head than the TPI. It's known for good flow characteristics and the ability to support higher engine speeds than the stock TPI. This manifold features a 5.75-inch long-runner. The throttle body is an LS1-style with a single 75mm butterfly.
The Fel Pro 1255 is .120 thick
The GM 89017465 is .060 thick
DYNO RUNS WITH CAM NO. 2
Holley Single-Plane GM Ram Jet Holley Stealth Ram
RPM TQ HP RPM TQ HP RPM TQ HP
2,900 418.6 232.3 2,900 422.6 232.3 2,900 430.6 238.9
3,000 417.9 238.7 3,000 421.5 240.7 3,000 430.6 246.0
3,100 420.2 248.0 3,100 422.0 249.1 3,100 430.1 253.9
3,200 419.1 255.4 3,200 421.8 257.0 3,200 429.6 261.7
3,300 417.6 262.4 3,300 419.4 263.5 3,300 427.3 268.5
3,400 415.6 269.0 3,400 417.4 270.2 3,400 424.4 274.7
3,500 414.6 276.3 3,500 415.1 276.6 3,500 419.7 279.7
3,600 413.4 283.3 3,600 412.9 283.0 3,600 415.8 285.0
3,700 414.0 291.7 3,700 409.7 288.6 3,700 415.0 292.4
3,800 415.2 300.4 3,800 414.1 299.6 3,800 420.6 304.3
3,900 419.4 311.5 3,900 420.1 311.9 3,900 429.1 318.6
4,000 427.0 325.2 4,000 428.8 326.6 4,000 433.2 329.9
4,100 435.6 340.1 4,100 433.9 338.7 4,100 440.5 343.9
4,200 441.7 353.2 4,200 435.7 348.4 4,200 445.3 356.1
4,300 441.0 361.1 4,300 432.9 354.4 4,300 445.8 365.0
4,400 439.3 368.1 4,400 432.5 362.4 4,400 447.0 374.5
4,500 439.4 376.5 4,500 433.0 371.0 4,500 449.7 385.3
4,600 441.6 386.8 4,600 433.5 379.7 4,600 452.4 396.3
4,700 443.2 396.6 4,700 437.5 391.5 4,700 455.3 407.5
4,800 445.5 407.2 4,800 440.1 402.3 4,800 458.2 418.8
4,900 448.1 418.1 4,900 444.5 414.7 4,900 460.1 429.2
5,000 451.8 430.1 5,000 448.3 426.8 5,000 459.9 437.8
5,100 452.7 439.6 5,100 450.8 437.7 5,100 459.4 446.1
5,200 452.2 447.8 5,200 453.1 448.6 5,200 458.4 453.9
5,300 453.0 457.2 5,300 452.0 456.1 5,300 458.2 462.4
5,400 450.4 463.1 5,400 448.2 460.9 5,400 454.8 467.7
5,500 447.5 468.6 5,500 447.7 468.8 5,500 452.7 474.1
5,600 442.9 472.3 5,600 444.3 473.7 5,600 448.8 478.5
5,700 439.0 476.5 5,700 440.5 478.1 5,700 446.0 484.0
5,800 433.6 478.8 5,800 435.7 481.2 5,800 439.0 484.9
5,900 426.2 478.8 5,900 428.7 481.5 5,900 431.5 484.7
6,000 419.4 479.1 6,000 421.7 482.7 6,000 422.9 483.2
6,100 409.3 475.8 6,100 412.4 478.7 6,100 414.6 477.8
PART NUMBERS
Company Part No. Item
Comp Cams 08-304-8 Cam No. 1 hydraulic roller
Bullet Cams Custom Cam No. 2 hydraulic roller
Edelbrock/Vortech 3817 High-Flo manifold base
FAST 301000 XFI programmable ECU
GM Performance Parts 12489371 Ram Jet 350 intake manifold
GM Performance Parts 17096144 Ram Jet 350 58mm throttle body
GM Performance Parts 12489371 Ram Jet 350 fuel rails
Holley 9901-107 Standard single-plane, multi-port, EFI,
aluminum intake manifold for Vortec heads
Holley 9900-171 1,000-cfm billet-aluminum four-barrel throttle body
Holley 9900-172 Standard single-plane, multi-port, EFI-intake fuel-rail kit
Holley 7542 Stealth Ram Vortec-head satin intake
Holley 534-186 Stealth Ram fuel-rail kit with adj. reg.
Holley 112-503 2x58mm throttle body
ACCEL *NA Large-tube runner
ACCEL *NA 58mm throttle body
*ACCEL has discontinued these parts, but they can still be found on the used market.
SLP, Edelbrock, and Arizona Speed make runners,and BBK makes a throttle body.
Intake Track Comparison With Traditional Pontiac
For a comparison to a traditional Pontiac intake track, we spoke with Jim Taylor Engine Service. Since Jim has a treasure trove of Pontiac parts at his fingertips, he was able to provide an approximate value for the induction-system length. His measurements were taken with a piece of welding wire that was first placed along the roof, and then the floor of the port. The values are added together and divided by 2 for an average.
A cast-iron factory Q-jet manifold runner falls between 8.0 and 9.5 inches. Cylinder No. 5 is the longest at 9.5 inches, while No. 8 is the shortest at 8 inches. A Holley Street Dominator intake has runner lengths that vary between 8 and 9 inches, while an Edelbrock Victor Jr. comes in with 8.5 and 9.0 inches. When the popular 6X cylinder-head runner was measured using the same method, the roof came in at 5.75 inches and the floor at 4.0 inches. The Ram Air IV cylinder head proved to have a floor length of 4 inches and a roof of 6 inches. The approximate intake-port runner length is 4.875 inches for the 6X and 5.0 inches for the Ram Air IV casting.
Using this data, a Pontiac with a set of 6X cylinder heads and a production intake manifold has an approximate mean total intake track length of 13.625 inches, or just about one half of the TPI system distance. -R.B.
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