Piston to Valve Clearance?
 

Has any one run into any problems? About at what point would you have to swap out pistons? I know every cam setup is going to be a little different, just curious to see what does and does not work.

good question but i don't think im gonna have that as a problem because i gotta keep it kinda streetable lol

Any of this help?

Engine Mechanical Specifications (6.2L)

Engine Type
V8

Displacement
6.2L
376 CID

Bore
103.241-103.259 mm
4.0065-4.0065 in

Stroke
92.0 mm
3.622 in

Compression Ratio
10.7:1

Firing Order
1-8-7-2-6-5-4-3

Spark Plug Gap
1.02 mm
0.04 in

Block

Camshaft Bearing Bore 1 and 5 Diameter
59.58-59.63 mm
2.345-2.347 in

Camshaft Bearing Bore 2 and 4 Diameter
59.08-59.13 mm
2.325-2.327 in

Camshaft Bearing Bore 3 Diameter
58.58-58.63 mm
2.306-2.308 in

Crankshaft Main Bearing Bore Diameter
69.871-69.889 mm
2.75-2.751 in

Crankshaft Main Bearing Bore Out-of-Round
0.006 mm
0.0002 in

Cylinder Bore Diameter
103.241-103.259 mm
4.0065-4.0065 in

Cylinder Head Deck Height - Measuring from the Centerline of Crankshaft to the Deck Face
234.57-234.82 mm
9.235-9.245 in

Cylinder Head Deck Surface Flatness - Measured within a 152.4 mm (6.0 in) Area
0.11 mm
0.004 in

Cylinder Head Deck Surface Flatness - Measuring the Overall Length of the Block Deck
0.22 mm
0.008 in

Valve Lifter Bore Diameter
21.417-21.443 mm
0.843-0.844 in

Camshaft

Camshaft End Play
0.025-0.305 mm
0.001-0.012 in

Camshaft Journal Diameter
54.99-55.04 mm
2.164-2.166 in

Camshaft Journal Out-of-Round
0.025 mm
0.001 in

Camshaft Lobe Lift - Intake
8.24 mm
0.324 in

Camshaft Lobe Lift - Exhaust
7.77 mm
0.306 in

Camshaft Runout - Measured at the Intermediate Journals
0.05 mm
0.002 in

Connecting Rod

Connecting Rod Bearing Clearance - Production
0.023-0.065 mm
0.0009-0.0025 in

Connecting Rod Bearing Clearance - Service
0.023-0.076 mm
0.0009-0.003 in

Connecting Rod Bore Diameter - Bearing End
56.505-56.525 mm
2.224-2.225 in

Connecting Rod Bore Out-of-Round - Bearing End - Production
0.004-0.008 mm
0.00015-0.0003 in

Connecting Rod Bore Out-of-Round - Bearing End - Service
0.004-0.008 mm
0.00015-0.0003 in

Connecting Rod Side Clearance
0.11-0.51 mm
0.00433-0.02 in

Crankshaft

Connecting Rod Journal Diameter - Production
53.318-53.338 mm
2.0991-2.0999 in

Connecting Rod Journal Diameter - Service
53.308 mm
2.0987 in

Connecting Rod Journal Out-of-Round - Production
0.005 mm
0.0002 in

Connecting Rod Journal Out-of-Round - Service
0.01 mm
0.0004 in

Connecting Rod Journal Taper - Maximum for 1/2 of Journal Length - Production
0.005 mm
0.0002 in

Connecting Rod Journal Taper - Maximum for 1/2 of Journal Length - Service
0.02 mm
0.00078 in

Crankshaft End Play
0.04-0.2 mm
0.0015-0.0078 in

Crankshaft Main Bearing Clearance - Production
0.02-0.052 mm
0.0008-0.0021 in

Crankshaft Main Bearing Clearance - Service
0.02-0.065 mm
0.0008-0.0025 in

Crankshaft Main Journal Diameter - Production
64.992-65.008 mm
2.558-2.559 in

Crankshaft Main Journal Diameter - Service
64.992 mm
2.558 in

Crankshaft Main Journal Out-of-Round - Production
0.003 mm
0.000118 in

Crankshaft Main Journal Out-of-Round - Service
0.008 mm
0.0003 in

Crankshaft Main Journal Taper - Production
0.01 mm
0.0004 in

Crankshaft Main Journal Taper - Service
0.02 mm
0.00078 in

Crankshaft Rear Flange Runout
0.05 mm
0.002 in

Crankshaft Reluctor Ring Runout - Measured 1.0 mm (0.04 in) Below Tooth Diameter
0.7 mm
0.028 in

Crankshaft Thrust Surface - Production
26.14-26.22 mm
1.029-1.0315 in

Crankshaft Thrust Surface - Service
26.22 mm
1.0315 in

Crankshaft Thrust Surface Runout
0.025 mm
0.001 in

Cylinder Head

Cylinder Head Height/Thickness - Measured from the Cylinder Head Deck to the Valve Rocker Arm Cover Seal Surface
120.2 mm
4.732 in

Surface Flatness - Block Deck - Measured within a 152.4 mm (6.0 in) Area
0.08 mm
0.003 in

Surface Flatness - Block Deck - Measuring the Overall Length of the Cylinder Head
0.1 mm
0.004 in

Surface Flatness - Exhaust Manifold Deck
0.13 mm
0.005 in

Surface Flatness - Intake Manifold Deck
0.08 mm
0.0031 in

Valve Guide Installed Height - Measured from the Spring Seat Surface to the Top of the Guide
17.32 mm
0.682 in

Intake Manifold

Surface Flatness - Measured at Gasket Sealing Surfaces and Measured Within a 200 mm (7.87 in) Area that Includes 2 Runner Port Openings
0.3 mm
0.118 in

Lubrication System

Oil Capacity - with Filter
5.2 liters
5.5 quarts

Oil Capacity - without Filter
4.7 liters
5.0 quarts

Oil Capacity - with Filter - RPO KPS
5.7 liters
6.0 quarts

Oil Pressure - Minimum - Hot
41 kPa at 1,000 engine RPM

124 kPa at 2,000 engine RPM

165 kPa at 4,000 engine RPM
6 psig at 1,000 engine RPM

18 psig at 2,000 engine RPM

24 psig at 4,000 engine RPM

Oil Pan

Front Cover Alignment - at Oil Pan Surface
0.0-0.5 mm
0.0-0.02 in

Crankshaft Rear Oil Seal Housing Alignment - at Oil Pan Surface
0.0-0.5 mm
0.0-0.02 in

Oil Pan Alignment - to Rear of Engine Block at Transmission Bell Housing Mounting Surface
0.0-0.1 mm
0.0-0.004 in

Piston Rings

Piston Ring End Gap - First Compression Ring - Measured in Cylinder Bore - Production
0.23-0.44 mm
0.009-0.017 in

Piston Ring End Gap - First Compression Ring - Measured in Cylinder Bore - Service
0.23-0.5 mm
0.009-0.0196 in

Piston Ring End Gap - Second Compression Ring - Measured in Cylinder Bore - Production
0.44-0.7 mm
0.017-0.027 in

Piston Ring End Gap - Second Compression Ring - Measured in Cylinder Bore - Service
0.44-0.76 mm
0.0173-0.03 in

Piston Ring End Gap - Oil Control Ring - Measured in Cylinder Bore - Production
0.18-0.75 mm
0.007-0.029 in

Piston Ring End Gap - Oil Control Ring - Measured in Cylinder Bore - Service
0.18-0.81 mm
0.007-0.032 in

Piston Ring to Groove Clearance - First Compression Ring - Production
0.04-0.085 mm
0.00157-0.00335 in

Piston Ring to Groove Clearance - First Compression Ring - Service
0.04-0.085 mm
0.00157-0.00335 in

Piston Ring to Groove Clearance - Second Compression Ring - Production
0.04-0.078 mm
0.00157-0.0031 in

Piston Ring to Groove Clearance - Second Compression Ring - Service
0.04-0.078 mm
0.00157-0.0031 in

Piston Ring to Groove Clearance - Oil Control Ring - Production
0.012-0.2 mm
0.0005-0.0078 in

Piston Ring to Groove Clearance - Oil Control Ring - Service
0.012-0.2 mm
0.0005-0.0078 in

Pistons and Pins

Pin - Piston Pin Clearance to Piston Pin Bore - Production
0.002-0.01 mm
0.0008-0.0004 in

Pin - Piston Pin Clearance to Piston Pin Bore - Service
0.002-0.015 mm
0.0008-0.0006 in

Pin - Piston Pin Diameter
23.952-23.955 mm
0.943-0.943 in

Pin - Piston Pin Fit in Connecting Rod Bore - Production
0.007-0.02 mm
0.00027-0.00078 in

Pin - Piston Pin Fit in Connecting Rod Bore - Service
0.007-0.0022 mm
0.00027-0.00086 in

Piston - Piston Diameter - Measured Over Skirt Coating
103.235-103.258 mm
4.064-4.065 in

Piston - Piston to Bore Clearance - Production
-0.036 to +0.016 mm
-0.0014 to +0.0006 in

Piston - Piston to Bore Clearance - Service Limit with Skirt Coating Worn Off
0.71 mm
0.0028 in

Valve System

Valves - Valve Face Angle
45 degrees

Valves - Valve Face Width
1.25 mm
0.05 in

Valves - Valve Lash
Net Lash - No Adjustment

Valves - Valve Lift - Intake
13.97 mm
0.55 in

Valves - Valve Lift - Exhaust
13.22 mm
0.52 in

Valves - Valve Seat Angle
46 degrees

Valves - Valve Seat Runout
0.05 mm
0.002 in

Valves - Valve Seat Width - Exhaust
1.78 mm
0.07 in

Valves - Seat Width - Intake
1.02 mm
0.04 in

Valves - Valve Stem Diameter - Production
7.955-7.976 mm
0.313-0.314 in

Valves - Valve Stem Diameter - Service
7.95 mm
0.313 in

Valves - Valve Stem-to-Guide Clearance - Production - Intake
0.025-0.066 mm
0.001-0.0026 in

Valves - Valve Stem-to-Guide Clearance - Service - Intake
0.093 mm
0.0037 in

Valves - Valve Stem-to-Guide Clearance - Production - Exhaust
0.025-0.066 mm
0.001-0.0026 in

Valves - Valve Stem-to-Guide Clearance - Service - Exhaust
0.093 mm
0.0037 in

Rocker Arms - Valve Rocker Arm Ratio
1.70:1

Valve Springs - Valve Spring Free Length
52.9 mm
2.08 in

Valve Springs - Valve Spring Installed Height
45.75 mm
1.8 in

Valve Springs - Valve Spring Load - Closed
400 N at 45.75 mm
90 lb at 1.8 in

Valve Springs - Valve Spring Load - Open
1175 N at 33.05 mm
264 lb at 1.30 in

- SK

there are plenty of cam manufacturers working on the LS3 and L99 that will be able to tell you if you need to change your pistons, however, unless you go with a pure donkey-di@# race cam, you shouldnt have a problem with valve/piston clearance.

that being said, the L99 and its VVT does require a little bit of finesse with the cams available for it as well as the tuning of the VVT to eliminate valve/piston contact.

but I wouldnt worry about the clearance unless you are going with a truly radical cam setup.