You can pull up any old cam on the crane cam site and get the valve event numbers @ .050 lift
exhast valve
Thread Starter
Racer
Joined: Nov 2007
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From: Forrest City Ar
Thanks Paul I think I got it. If I use the 1.60 without the decemal 160 I get 1.84 tube size and 23" primary. that seems right before When I left the decemal in I was getting a tube size of 1.10" and lenght of 50" I knew that wasn't right.
Pro
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From: Jacksonville , NC
Team Owner
Joined: Apr 1999
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
Thread Starter
Racer
Joined: Nov 2007
Posts: 279
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From: Forrest City Ar
so if my engine builder told me that my cam was exhasrt duration @ .50 was 244 that is what they want in the calculation? They are very vage about cam spec's I think it may be like a trade secert for these guys because they told me lift was I-510 & E-510 duration @.50 I-244 & E-244. Are not these numbers usually a little different or did they hand grind them to the same?
Burning Brakes
Joined: Feb 2006
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From: AL
they can be the same
that calculator is looking for the exhaust event, probably at 0.05, but does not specify - would have to get the book or email the webmaster
the thing looks like it won't give you a header size that you can go out and buy anyway. probably need the book and formula to see what the results really mean
that calculator is looking for the exhaust event, probably at 0.05, but does not specify - would have to get the book or email the webmaster
the thing looks like it won't give you a header size that you can go out and buy anyway. probably need the book and formula to see what the results really mean
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Thread Starter
Racer
Joined: Nov 2007
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From: Forrest City Ar
the 244 number give bad results. can anyone suggest Primary header size and length based on this info 350" Dart heads 64cc, 200, Holly 4150 650. torque curve 2000-5000, 400ft lb. steep power curve from 2000 to 6000 holding thu 7000 then droping off peak 6700 430HP. engine guy says 1 3\4 talk to Mr. Stahl yesterday he said 1 5\8. The problem is I have factoru side pipe covers I want to run my system under.
Team Owner
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From: Reno Nevada
2024 C3 of the Year Finalist- Modified
You see these numbers on a cam card?
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 2 BTDC 40 ABDC 109 222 °
Exhaust 56 BBDC (2) BTDC 119 234 °
It is saying that the exhaust valve closes 56 degrees Before Bottom Dead Center.
IMO - 1 5/8th by @ 30 -34 inches and a 2.5 X 16 inch collector is about the best sub 450 hp header. As you go up in tube diameter the flow is slower so they need a shorter 1 3/4 X 28 primary
Camshaft Specification Card BACK TO LIST
Part Number: 113801 Grind Number: H-278-2 (REPLACES HMV-278-2)
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1957 1987 CHEVROLET 8 GOOD IDLE, DAILY PERFORMANCE USAGE, MILD BRACKET RACING, 3000-3400 CRUISE RPM, 9.5 TO 10.75 COMPRESSION RATIO ADVISED. BASIC RPM 2500-5500
Engine Size Configuration
262-400 C.I. V
Valve Setting: Intake .000 Exhaust .000 HOT
Lift: Intake @Cam 3114 @Valve 467 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3294 @Valve 494
Rocker Arm Ratio 1.5
Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 26 BTDC 72 ABDC 278 °
Exhaust 80 BBDC 30 ATDC 290 °
Spring Requirements: Triple Dual Outer Inner
Part Number 99848
Loads Closed 114 LBS @ 1.700 or 1 45/64
Open 324 LBS @ 1.230
Recommended RPM range with matching components
Minimum RPM 2200
Maximum RPM 6200
Valve Float 6800
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 2 BTDC 40 ABDC 109 222 °
Exhaust 56 BBDC (2) BTDC 119 234 °
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 2 BTDC 40 ABDC 109 222 °
Exhaust 56 BBDC (2) BTDC 119 234 °
It is saying that the exhaust valve closes 56 degrees Before Bottom Dead Center.
IMO - 1 5/8th by @ 30 -34 inches and a 2.5 X 16 inch collector is about the best sub 450 hp header. As you go up in tube diameter the flow is slower so they need a shorter 1 3/4 X 28 primary
Camshaft Specification Card BACK TO LIST
Part Number: 113801 Grind Number: H-278-2 (REPLACES HMV-278-2)
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1957 1987 CHEVROLET 8 GOOD IDLE, DAILY PERFORMANCE USAGE, MILD BRACKET RACING, 3000-3400 CRUISE RPM, 9.5 TO 10.75 COMPRESSION RATIO ADVISED. BASIC RPM 2500-5500
Engine Size Configuration
262-400 C.I. V
Valve Setting: Intake .000 Exhaust .000 HOT
Lift: Intake @Cam 3114 @Valve 467 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 3294 @Valve 494
Rocker Arm Ratio 1.5
Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 26 BTDC 72 ABDC 278 °
Exhaust 80 BBDC 30 ATDC 290 °
Spring Requirements: Triple Dual Outer Inner
Part Number 99848
Loads Closed 114 LBS @ 1.700 or 1 45/64
Open 324 LBS @ 1.230
Recommended RPM range with matching components
Minimum RPM 2200
Maximum RPM 6200
Valve Float 6800
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 2 BTDC 40 ABDC 109 222 °
Exhaust 56 BBDC (2) BTDC 119 234 °
Last edited by gkull; Apr 4, 2008 at 05:46 PM.
