Cams & Idle Vacuum
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From: Mercedes Norte, Heredia, Costa Rica
Car: 1984 Z28 Hardtop
Engine: 383 Carb
Transmission: 4L60
Axle/Gears: 3.54 Dana 44
Cams & Idle Vacuum
Just curious, what kinds of cam grinds is everyone running, and how many inches of vacuum are you pulling at what idle speed?
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1984 Silver Z28, 383 cid 4 bolt, ARP Fasteners, 2 1/2" Cowl Induction Hood, 600 cfm Performer Carburetor, Torker II Intake, Performer RPM Heads, XE268H Cam, Magnum Roller Tip Rockers, MSD6A Ignition, Blaster2 Coil, HEI Distributor w/ Adjustable Advance, 700R4, TransGo SK, 2.73:1 Limited Slip Dana 44, Terminator Headers, Custom 3" TIG Welded Stainless Exhaust, Flowmaster Muffler, 4 Wheel Disc Brakes, Oil Cooler
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1984 Silver Z28, 383 cid 4 bolt, ARP Fasteners, 2 1/2" Cowl Induction Hood, 600 cfm Performer Carburetor, Torker II Intake, Performer RPM Heads, XE268H Cam, Magnum Roller Tip Rockers, MSD6A Ignition, Blaster2 Coil, HEI Distributor w/ Adjustable Advance, 700R4, TransGo SK, 2.73:1 Limited Slip Dana 44, Terminator Headers, Custom 3" TIG Welded Stainless Exhaust, Flowmaster Muffler, 4 Wheel Disc Brakes, Oil Cooler
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Ape,
Some of my observations:
1974 355, 11:1, 2.02-1.60 valves, Crane .474/.474, 222°/222°, 111 LSA, holds about 15" Hg at 1,050 RPM through a POS Holley 4160. Made 420 BHP on engine dyno.
1994 LT1 350 10.5:1, CompCams .533/.544, 220°/235°, 114° LSA, holds about 17.5" @ 900 RPM. Should make about 385-390 HP at flywheel.
1986 LP9 TPI, "LA" cam, .373/.410, 190°/207°, 110° LSA, holds about 19" @ 850 RPM. Might beat a couple of eggs if you hold them right (has no *********). Maybe 210 RWHP?
Generally, more overlap = less vacuum. Less vacuum = more trouble on a stock PCM.
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Later,
Vader
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"Make Me Bad"
Adobe Acrobat Reader 4.0
Some of my observations:
1974 355, 11:1, 2.02-1.60 valves, Crane .474/.474, 222°/222°, 111 LSA, holds about 15" Hg at 1,050 RPM through a POS Holley 4160. Made 420 BHP on engine dyno.
1994 LT1 350 10.5:1, CompCams .533/.544, 220°/235°, 114° LSA, holds about 17.5" @ 900 RPM. Should make about 385-390 HP at flywheel.
1986 LP9 TPI, "LA" cam, .373/.410, 190°/207°, 110° LSA, holds about 19" @ 850 RPM. Might beat a couple of eggs if you hold them right (has no *********). Maybe 210 RWHP?
Generally, more overlap = less vacuum. Less vacuum = more trouble on a stock PCM.
------------------
Later,
Vader
------------------
"Make Me Bad"
Adobe Acrobat Reader 4.0
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Joined: Feb 2000
Posts: 322
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From: San Antonio, Tx
Car: 2001 Camaro Z28/1995 Camaro Z28
Engine: just a little 5.7(LS1-320/340 RW)
Transmission: SMOOOOOOTH T-56/Auto. . .
Axle/Gears: 3.42 and 2.73
1978 305, 9.0:1, 1.84-1.50 valves, Engle ~.470/.470, 215/215, 115 LSA, holds about 17"Hg @ 800+ RPM using a Holley 4160.
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Duffster (age 31)
BEAT DOWN HARD 88' Camaro Sport Coupe,
1978 Caprice Classic 305 motor havin'(WITH NO COMPUTER),84' 700R4 Tranny usin', 84' Z-28 Nose clip wearin',
84' Z-28 Hood covered,
AND THE TIRES:
245/60-16 Firehawk SS20 on Firbird rim(1-passenger rear),
235/55-15 BF Goodrich's on CompTA's on Z28 rims(2-on front),
235/60-16 Pirelli P600 w/a curb check or 3 also on Firebird rim(1-drivers rear),
REAR HATCH MASTER OF ALL!!!
Duffster_Camaro@HOTMAIL.COM
Owner of the Camaro 0 out of 10 Third-genners approve of, no longer part of the non-existent Iowa crew.
------------------
Duffster (age 31)
BEAT DOWN HARD 88' Camaro Sport Coupe,
1978 Caprice Classic 305 motor havin'(WITH NO COMPUTER),84' 700R4 Tranny usin', 84' Z-28 Nose clip wearin',
84' Z-28 Hood covered,
AND THE TIRES:
245/60-16 Firehawk SS20 on Firbird rim(1-passenger rear),
235/55-15 BF Goodrich's on CompTA's on Z28 rims(2-on front),
235/60-16 Pirelli P600 w/a curb check or 3 also on Firebird rim(1-drivers rear),
REAR HATCH MASTER OF ALL!!!
Duffster_Camaro@HOTMAIL.COM
Owner of the Camaro 0 out of 10 Third-genners approve of, no longer part of the non-existent Iowa crew.
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