Hi evryone. I posted this question under V8 Tech but haven't gotten any responses. Does anyone know if the crank and pistons in an LS3 are cast or forged??

Thanks.....

 

Looks like the crank shaft was cast.... Don't see anything about pistons:

http://www.gmpowertrain.com/Librarie...rine.sflb.ashx

 

I'm curious too... Isn't it a 10.7 CR on the LS3? Forged would make more sense...but I'm not sure been looking for a bit myself and can't seem to find a definite answer.

 

Thanks for the info. If the crank is cast the pistons are likely too. It makes a difference on how much boost you can add if you supercharge or turbo.

I wonder if this marine engine has same components as the car engine? HP is rated at 418 on the marine version on premium fuel.

The compression in the LS3 is 10.7 while the L99 is 10.4.

 

LS3 Engine specs

Balanced:
Internal
Block Part Number:
12584727
Bore x stroke (in):
4.06 x 3.62 (103.25 x 92mm)
Camshaft duration (@.050 in):
204 degree intake / 211 degree exhaust
Camshaft Part Number:
12603844
Camshaft Type:
Hydraulic roller
Compression ratio:
10.7:1
Connecting rods (P/N 12617570):
Powdered metal
Crankshaft (P/N 12597569):
Nodular iron
Cylinder heads (P/N 12598594):
LS3 rectangle port; as cast with 68cc chambers
Displacement (cu in):
376 cu in (6.2L)
Engine type:
LS Series Gen IV small-block V-8
Maximum recommended rpm:
6600
Pistons Part Number:
19165089
Pistons Type:
Hypereutectic aluminum
Recommended fuel:
92 octane
Reluctor wheel:
58X
Rocker arm ratio:
1.7:1
Rocker arms exhaust Part Number:
10214664
Rocker arms exhaust Type:
Investment cast, roller trunnion
Rocker arms intake Part Number:
12569167
Rocker arms intake Type:
Investment cast, roller trunnion
Valve Lift (in):
.551 intake / .522 exhaust
Valve size (in):
2.16 intake / 1.59 exhaust

 

nice post!!! ^

 

Thanks for the post z28pete. That certainly leaves no more questions on the tech of the LS3.

 

^^^ Awesome post. Thanks!