New guy with 383 and cam questions
06-25-2020, 08:32 PM
#33
Registered
I "borrowed" SB's cam from his 350 for my 9.8:1 partially forged 383.
It's
Comp Cams OE roller style CS 268XFI HR13 Cam
Valve Lift .570” Intake .565” Exhaust
Duration at .050 lift, 218 Intake 224 Exhaust
Advertised duration intake 268, exhaust 276
113 Degree Lobe Separation Angle
Intake Centerline 109 Degrees, intake close 63 degrees after bottom dead center
I got 5300 RPM last September at 65 degrees temperature with half a tank of fuel. If I had kept on it and really trimmed it out there might have been more rpm, but not much.
That was running a 21" Mirage plus through a 1.50 ratio Alpha gen 2 with Amsoil Severe Gear in it and a drive shower.
I have ported iron Dart Iron Eagles, a fresh Davis Unified Ignition, Comp Beehive springs and Comp short travel lifters. My boat is a big fatty compared to OPs.
I always had trouble with higher rpms til last year when i opened up the runners. You gotta breathe to use all the capabilities of the engine.
It's
Comp Cams OE roller style CS 268XFI HR13 Cam
Valve Lift .570” Intake .565” Exhaust
Duration at .050 lift, 218 Intake 224 Exhaust
Advertised duration intake 268, exhaust 276
113 Degree Lobe Separation Angle
Intake Centerline 109 Degrees, intake close 63 degrees after bottom dead center
I got 5300 RPM last September at 65 degrees temperature with half a tank of fuel. If I had kept on it and really trimmed it out there might have been more rpm, but not much.
That was running a 21" Mirage plus through a 1.50 ratio Alpha gen 2 with Amsoil Severe Gear in it and a drive shower.
I have ported iron Dart Iron Eagles, a fresh Davis Unified Ignition, Comp Beehive springs and Comp short travel lifters. My boat is a big fatty compared to OPs.
I always had trouble with higher rpms til last year when i opened up the runners. You gotta breathe to use all the capabilities of the engine.
Last edited by NHGuy; 06-25-2020 at 08:44 PM.
