Old School HP500
06-28-2024 | 12:19 PM
#3
Fast Singles Club
Joined: Oct 2011
Posts: 4,042
Likes: 490
From: Raystown Lake , Pa.
I would suggest using the 500EFI cam instead of the reversion prone HP cam. Still have some nice parts from my HP500 that will be going up for sale soon. Valve covers, circulating pump with blue pulley, blue 3 groove crank pulley and Gil/Merc exhaust manifolds.
Last edited by the deep; 06-28-2024 at 12:21 PM.
06-28-2024 | 01:07 PM
#4
Charter Member # 55
Joined: Oct 2000
Posts: 20,255
Likes: 2,504
From: Omaha/LOTO
Bottom end is the same as a 502mag. GM forged crank, rods, pistons. 8.75:1 compression.
GM rect port heads with I think 2.25 intake and 1.88 valves. Crane gold roller rockers.
Cam specs are out there, but stock cam had reversion issues. Better off to use a 500efi cam or 525EFI cam. Teague has copies of both.
Dart single plain intake and Holley 800cfm carb.
Gil Exhaust and some expensive blue paint
If you're starting from scratch, better off to make it into a 540ci
GM rect port heads with I think 2.25 intake and 1.88 valves. Crane gold roller rockers.
Cam specs are out there, but stock cam had reversion issues. Better off to use a 500efi cam or 525EFI cam. Teague has copies of both.
Dart single plain intake and Holley 800cfm carb.
Gil Exhaust and some expensive blue paint
If you're starting from scratch, better off to make it into a 540ci
06-28-2024 | 10:50 PM
#5
Registered
Joined: Jun 2004
Posts: 8,219
Likes: 573
From: St-Hyacinthe, quebec, canada
Bottom end is the same as a 502mag. GM forged crank, rods, pistons. 8.75:1 compression.
GM rect port heads with I think 2.25 intake and 1.88 valves. Crane gold roller rockers.
Cam specs are out there, but stock cam had reversion issues. Better off to use a 500efi cam or 525EFI cam. Teague has copies of both.
Dart single plain intake and Holley 800cfm carb.
Gil Exhaust and some expensive blue paint
If you're starting from scratch, better off to make it into a 540ci
GM rect port heads with I think 2.25 intake and 1.88 valves. Crane gold roller rockers.
Cam specs are out there, but stock cam had reversion issues. Better off to use a 500efi cam or 525EFI cam. Teague has copies of both.
Dart single plain intake and Holley 800cfm carb.
Gil Exhaust and some expensive blue paint
If you're starting from scratch, better off to make it into a 540ci
06-29-2024 | 04:00 AM
#6
Registered
Joined: Nov 2004
Posts: 14,108
Likes: 3,694
From: On A Dirt Floor
Quoting myself 
For Gen VI HP500's cam I have the following in my notes:
Merc HP500 Carb
Crane Gen VI#169611 Grind#HR-284-2S-10IG
Adv 284, 292 at .004” Lift with 1.7 .576 / .598
At .050” 222, 230
ICL 105, ECL 115
LSA 110
Part Number: 169611 Grind Number: HR-284-2S-10 IG
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1996 Up CHEVROLET 8 HYD. ROLLER WITH CAST IRON DISTRIBUTOR DRIVE GEAR
Engine Size Configuration
454-502 C.I. V
Valve Setting: Intake .000 Exhaust .000 HOT
Lift: Intake @Cam 339 @Valve 576 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 352 @Valve 598
Rocker Arm Ratio 1.70
Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 33.0 BTDC 71.0 ABDC 284 °
Exhaust 77.0 BBDC 35.0 ATDC 292 °
Spring Requirements: Triple Dual Outer Inner
Part Number 99896
Loads Closed 150 LBS @ 1.900 or 1 29/32
Open 441 LBS @ 1.330
Recommended RPM range with matching components
Minimum RPM 2500
Maximum RPM 6000
Valve Float 6500
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 6.0 BTDC 36.0 ABDC 105 222 °
Exhaust 50.0 BBDC 0.0 BTDC 115 230 °
Remarks:
CRANE 16535-16 LONG TRAVEL HYDRAULIC ROLLER- LIFTERS MUST BE USED WITH GREATER THAN .570 LIFT CAMSHAFTS TO PREVENT ALIGNMENT BAR DISENGAGEMENT.
Merc HP500 Carb
Crane Gen VI#169611 Grind#HR-284-2S-10IG
Adv 284, 292 at .004” Lift with 1.7 .576 / .598
At .050” 222, 230
ICL 105, ECL 115
LSA 110
Part Number: 169611 Grind Number: HR-284-2S-10 IG
Engine Identification:
Start Yr. End Yr. Make Cyl Description
1996 Up CHEVROLET 8 HYD. ROLLER WITH CAST IRON DISTRIBUTOR DRIVE GEAR
Engine Size Configuration
454-502 C.I. V
Valve Setting: Intake .000 Exhaust .000 HOT
Lift: Intake @Cam 339 @Valve 576 All Lifts are based
on zero lash and theoretical rocker arm ratios.
Exhaust @ Cam 352 @Valve 598
Rocker Arm Ratio 1.70
Cam Timing: TAPPET @.004
Lift: Opens Closes ADV Duration
Intake 33.0 BTDC 71.0 ABDC 284 °
Exhaust 77.0 BBDC 35.0 ATDC 292 °
Spring Requirements: Triple Dual Outer Inner
Part Number 99896
Loads Closed 150 LBS @ 1.900 or 1 29/32
Open 441 LBS @ 1.330
Recommended RPM range with matching components
Minimum RPM 2500
Maximum RPM 6000
Valve Float 6500
Cam Timing: TAPPET @.050
Lift: Opens Closes Max Lift Duration
Intake 6.0 BTDC 36.0 ABDC 105 222 °
Exhaust 50.0 BBDC 0.0 BTDC 115 230 °
Remarks:
CRANE 16535-16 LONG TRAVEL HYDRAULIC ROLLER- LIFTERS MUST BE USED WITH GREATER THAN .570 LIFT CAMSHAFTS TO PREVENT ALIGNMENT BAR DISENGAGEMENT.
06-29-2024 | 06:58 AM
#7
Registered
Joined: Dec 2013
Posts: 1,019
Likes: 457
From: Bourbonnais, IL
Free horsepower I believe is the concept. You're not going to stress the moving parts anymore with larger displacement and it will make more power. The more displacement argument in a boat just keeps getting better when you start modifying the engine with things like forced induction.
06-29-2024 | 08:03 AM
#8
Registered
Joined: Jun 2007
Posts: 7,318
Likes: 1,824
From: Merritt Island, FL
and not a tall deck block. Helps if its a twin.
Free horsepower I believe is the concept. You're not going to stress the moving parts anymore with larger displacement and it will make more power. The more displacement argument in a boat just keeps getting better when you start modifying the engine with things like forced induction.
