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Thought I'd post some interesting new facts on the new family 60degreev6 "LZ" engines These are the "High Value" engines.
3900 "LZ9" V6 and its related smaller brother the 3500 "LZ4" and "LZE"
NOTE: this is not the same 3500 we've seen in the past few years here. This is a new 3500 variant. Yeah can get quite confusing..
The 3900 and 3500 LZ engines share the same block.
3.9L displacement, (238cid) 99mm Bore, 84mm stroke. (yes LS1's have a a 99mm bore too)
3.5L displacement 99mm bore 76mm stroke
Block centerline is changed by 3mm.
Camshaft bearings are larger journal diameter (55mm now up from 51mm we are used to) to accomodate larger camshaft profiles.
9.8:1 compression ratio (at least for the 3900, havn't checked the 3500 yet)
Camshaft phasing, which can advance and retard the camshaft 25 degree's throughout the powerband to create a broad flat torque/powerband.
Tuned Plenum with Intake Manifold Tuning Valve, -opens and closes dual ports in the plenum to create a low and high rpm runners/plenum.
The 3900 uses a larger ported lower Intake manifold,
There is a larger 72mm throttle body on the Plenum,
Heads are different, and do not share any related component with previous 60v6 heads. 47.5mm (1.87inch) Intake valves and 38.7mm (1.52inch) exhaust valves are in the heads which feature revised port shapes and different combustion chamber shapes. as far as the rockers all I know is that "Features rocker arms similar to those found on LS1 V8's" What the actual ratio is not sure if its still 1.6:1 or now 1.7:1 like the LS engines.
Exhaust manifolds are new redesigned and tuned for maximum performance (as per what GM claims anyways)
Each cylinder bores have piston oil squirters to keep pistons cool.
Features a High volume oil pump to accomodate the larger oil system requirements from the squirters and as well as the cam phaser actuator setup. The Oil pump drive gear is different and cannot be interchanged withe the previous engines drive gear.
New style Delphi Multec 3.5 injectors featuring new design features.
New redesigned Cooling system which flows the coolant through and around the block in a different more uniform path through the engine.
There are other small changes and whatnot that I know I'm missing.
3900 "LZ9" V6 and its related smaller brother the 3500 "LZ4" and "LZE"
NOTE: this is not the same 3500 we've seen in the past few years here. This is a new 3500 variant. Yeah can get quite confusing..
The 3900 and 3500 LZ engines share the same block.
3.9L displacement, (238cid) 99mm Bore, 84mm stroke. (yes LS1's have a a 99mm bore too)
3.5L displacement 99mm bore 76mm stroke
Block centerline is changed by 3mm.
Camshaft bearings are larger journal diameter (55mm now up from 51mm we are used to) to accomodate larger camshaft profiles.
9.8:1 compression ratio (at least for the 3900, havn't checked the 3500 yet)
Camshaft phasing, which can advance and retard the camshaft 25 degree's throughout the powerband to create a broad flat torque/powerband.
Tuned Plenum with Intake Manifold Tuning Valve, -opens and closes dual ports in the plenum to create a low and high rpm runners/plenum.
The 3900 uses a larger ported lower Intake manifold,
There is a larger 72mm throttle body on the Plenum,
Heads are different, and do not share any related component with previous 60v6 heads. 47.5mm (1.87inch) Intake valves and 38.7mm (1.52inch) exhaust valves are in the heads which feature revised port shapes and different combustion chamber shapes. as far as the rockers all I know is that "Features rocker arms similar to those found on LS1 V8's" What the actual ratio is not sure if its still 1.6:1 or now 1.7:1 like the LS engines.
Exhaust manifolds are new redesigned and tuned for maximum performance (as per what GM claims anyways)
Each cylinder bores have piston oil squirters to keep pistons cool.
Features a High volume oil pump to accomodate the larger oil system requirements from the squirters and as well as the cam phaser actuator setup. The Oil pump drive gear is different and cannot be interchanged withe the previous engines drive gear.
New style Delphi Multec 3.5 injectors featuring new design features.
New redesigned Cooling system which flows the coolant through and around the block in a different more uniform path through the engine.
There are other small changes and whatnot that I know I'm missing.
Very cool stuff. Id like to check out the heads and see what they changed as far as shape goes. Im gonna need a new setup for the flowbench to go to that bore size. Fun fun fun
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