Can someone tell me the spec. on the C5 eng. heads. Valve size , flow.

 

Cylinder Head

Cylinder Head Engine Block Deck Flatness (Measured within a 152.4 mm (6.0 in) area) 0.08 mm 0.003 in

Cylinder Head Engine Block Deck Flatness (Measuring the Overall Length of the Cylinder Head) 0.1 mm 0.004 in

Cylinder Head Exhaust Manifold Deck Flatness
0.22 mm 0.008 in

Cylinder Head Intake Manifold Deck Flatness
0.22 mm 0.008 in

Cylinder Head Height (Measured from the Cylinder Head Deck to the Valve Rocker Arm Cover Seal Surface)
120.2 mm (Minimum) 4.732 in (Minimum)

Valve System

Valve Face Angle 45 degrees

Valve Guide Installed Height (Measured from the Cylinder Head Spring Seat Surface to the Top of the Valve Guide) 17.32 mm 0.682 in

Valve Lash Net Lash--No Adjustment

Valve Lift (Intake) 11.99 mm 0.472 in

Valve Lift (Exhaust) 12.15 mm 0.479 in

Valve Lifter Hydraulic Roller

Valve Margin 1.25 mm (Minimum) 0.05 in (Minimum)

Valve Rocker Arm Ratio 1.70:1

Valve Seat Angle 46 degrees

Valve Seat Runout 0.05 mm (Maximum) 0.002 in (Maximum)

Valve Seat Width (Intake) 1.02 mm 0.04 in

Valve Seat Width (Exhaust) 1.78 mm 0.07 in

Valve Spring Free Length 52.9 mm 2.08 in

Valve Spring Installed Height (Intake) 45.75 mm 1.8 in

Valve Spring Installed Height (Exhaust) 45.75 mm 1.8 in

Valve Spring Pressure (Closed) 340 N at 45.75 mm 76 lb at 1.8 in

Valve Spring Pressure (Open) 980 N at 33.55 mm 220 lb at 1.32 in

Valve Stem Clearance (Production--Intake) 0.025-0.066 mm 0.001-0.0026 in

Valve Stem Clearance (Production--Exhaust) 0.025-0.066 mm 0.001-0.0026 in

Valve Stem Clearance (Service--Intake) 0.093 mm (Max) 0.0037 in (Max)

Valve Stem Clearance (Service--Exhaust) 0.093 mm (Max) 0.0037 in (Max)

Valve Stem Diameter (Production) 7.955-7.976 mm 0.313-0.314 in

Valve Stem Diameter (Service) 7.95 mm (Min) 0.313 in (Min)

Valve Stem Oil Seal Installed Height (Measured from the Valve Spring Shim to Top Edge of Seal Body) 18.1-19.1 mm 0.712-0.752 in






[Modified by WhiteC5Vette, 3:46 PM 3/2/2003]

 

2.00 " Intake
1.55 " exhaust
:cheers:

 

WOW!!!!! Those heads stock I have heard can flow 385 cfm. This is amazing if those numbers are with that size valve!!!

Keith

 

Most LS1 heads with high flow #s are heavily reworked and fitted with larger valves. Have yet to see any LS1/LS6 head flow 385 cfm....

 

I think you'd have to start with C5R heads to flow 385 cfm. :cheers:

 

Yes, my mistake. I thought these where C5R heads. Best flowing LS6 heads I have see are 340 CFM and best LS1 heads are 300 CFM. Of course, both of those are full out race ports.

Keith