Wow... The gen 4 small blocks are REALLY getting cheap!

[mylesm260]

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GM Marine's 6.0L

-Direct Swap for our Generation 1 Small blocks and 4.3's
-Aluminum
-Variable Valve Timing
-Already in marine production (Idmar and GM marine)
-Truck and Marine already use the same ignition and intake components
-Engines are WAY WAY tougher (high RPM) than our old Gen 1 Small Blocks (they have 6 bolt mains for crying out loud)



That 5.3 Liter is rated for an Honest 290 NET HP in a truck with the restrictive exhaust and catalytic converters. In a Boat it would make an honest 320 HP, perfect for an alpha-1.

Variable valve timing means that it will make more torque than the old 5.7's from idle to red-line! it also means much lower fuel consumption.

Aluminum means you're boat will be much lighter! (and will obviously require a heat exchanger)



The ONLY problem with these engines, is nobody makes exhaust manifolds for them, except indmar, and they're really expensive (2010 EPA compliant with Catalytic converters), and they're not designed to work with mercruiser Y pipes.

The only real solution I could think of would be to have a custom manifold flange adapter plate made up on a C+C machine, and use the old GM Big block manifolds, as they have equal port spacing.

Anyone have any thoughts?

Marine starters and alternators are available for these engines. And because they are coil near plug ignition, no cap and rotor is needed.

The electronics I'm sure I can figure out, EFI is my forte, I'm 100% sure I can get it running and tuned in a boat (I'm running truck EFI on my 4.3 right now)

 

[fabrimacator21]

Re: Wow... The gen 4 small blocks are REALLY getting cheap!

They are IMHO the best bang for the buck out there today. I'm looking into swapping out my 355 for a 6.0 for my blazer.


The Lq9 and lq4 are the two I'm looking at for my truck. Gm's power rating are a bit modest too. Theres dyno tests where a BONE stock Lq4 (rated at 325hp and 380 ft lbs) with some headers made 380hp and 440 ft lbs of tq.

Not sure what all would be required to make one marine worthy but they can be had with less then 50k miles on them for 1200 bucks.


Tq rivals big blocks too... these things are making 300 ft lbs OFF IDLE.

 

[mylesm260]

Re: Wow... The gen 4 small blocks are REALLY getting cheap!

Like I was saying, for all practical purposes the truck vortec's already ARE marine motors, they just need a starter, and alternator and manifolds.

Same bolt pattern as our Gen 1's.

Here's my train of thought for the adapter plate... Kind of a round to square thing.

They are IMHO the best bang for the buck out there today. I'm looking into swapping out my 355 for a 6.0 for my blazer.

Yeah, These motors really are fantastic. In a recent truck comparison, the GM gen 4 small block powered truck outperformed and got better mileage than toyota's V8 powered truck.

To put things in perspective, the toyota engine has 4 cam shafts (DOHC) and 32 valve (4 valves per cylinder)

and the GM engine has 1 cam shaft and 16 valve.

Despite the massive difference in "technology" the GM gen IV vortec is a smaller package, that weighs less and gets more power and better milage.

Tq rivals big blocks too... these things are making 300 ft lbs OFF IDLE.

Variable valve timing! it's like having a high torque cam, and a racing cam all at the same time!

Advanced timing @ idle and retarded timing @ high rpms, it's perfect.

In comparison, our gen 1 engines are cave-man engines.

 

[mylesm260]

Re: Wow... The gen 4 small blocks are REALLY getting cheap!

Hmmm

Manifolds

Engine in boat with manifolds (not Sterndrive)



GM Powertrain dives into marine market


The Vortec 6000 V8 from GM Powertrain includes a symmetrical runner composite intake manifold designed to optimize airflow and allow for enhanced corrosion resistance.

For 2002 applications, the GM Powertrain Vortec 6000 V8 will be available to several marine OEMs. The Vortec 6000 engine is featured in several GM trucks, including the 2001 GMC Sierra C3, GMC Yukon Denali, and Chevrolet Suburban. With a targeted power rating of 242 kW (325 hp) at 5000 rpm and 500 N?m (370 lb?ft) at 4000 rpm in the pickup range, the 6.0-L engine produces an additional 52 kW (70 hp) and 54 N?m (40 lb?ft) over the 5.7-L. For marine applications, the Vortec 6000 delivers 260 kW (350 hp) at 5200 rpm and 518 N?m (382 lb?ft) at 4400 rpm.

GM Powertrain engineers used the proven small-block architecture as a basis for creating the Vortec 6000 and focused on only those improvements that would provide enhancements to engine torque and power delivery. The engine has a deep-skirt cast-iron block and features aluminum cylinder heads, similar in design to those developed for the 2001 LS6 Corvette V8, which allow for better flow, are 25 kg (56 lb) lighter, and have improved valve-seat durability. They also dissipate heat more quickly, reduce overall cooling requirements, and allow an increase in spark advance without pre-ignition.

Intake and exhaust ports are identical to those in the LS6 head, for an increase in volumetric efficiency. The Vortec 6000 heads have a larger combustion chamber than the LS6 to accommodate the increased engine displacement. New, more durable, multi-layer-steel head gaskets maintain proper heat conductivity with the engine's cast-iron engine block.

A new steel camshaft, unique to the Vortec 6000, is the single biggest contributor to the increase in power. The cam increases valve lift and duration slightly to take full advantage of the increase in volumetric efficiency allowed by the new cylinder head design. Performance improvements are also garnered with the addition of a lower-restriction exhaust system. A coil-near-plug ignition system delivers increased ignition energy, helps reduce emissions, and improves idle quality.


GM, Fountain Powerboats, and Mercury MerCruiser jointly developed a concept boat, VX6, that features two enhanced Vortec 6000 engines.

The block has six-bolt main bearing caps, which help in the overall rigidity and the reduction of NVH. A new firing order reduces stress on the internally balanced and counterweighted cast nodular iron crankshaft by 7%.

The Vortec 6000 has alternative-fuel capabilities (compressed natural gas or liquid propane gas) in the heavy-duty models. An advanced coolant-loss protection system protects the engine in the event of coolant drainage, either partial or total. If a loss is detected, the computer limits engine power and allows the engine to run as an air-cooled system, giving the driver a limited ability to find a repair facility or suitable pull-off area.

GM engines that are sold to the marine industry are designed from the beginning to meet both the vehicle and marine customer's requirements. Some of the specially designed marine features for the Vortec 6000 include a symmetrical runner composite intake manifold designed to optimize airflow and allow for enhanced corrosion resistance. The engine is also equipped with a PCV system for emissions control, proven overhead valve technology, and a coil-per-cylinder ignition system that delivers a dedicated spark to each spark plug and improves overall engine performance.

The LS6 inspired aluminum cylinder heads are designed with increased volumetric efficiency for maximum power in this application. An assortment of accessory parts such as electronic throttle control hardware, ECM, sight shield, and related parts will be available in kit form to package the Vortec 6000.

Because about 25% of GM's larger displacement engines are typically sold for marine use, much of the validation on the Vortec 6000 was done using the marine market's more severe test parameters. In one particular test, called the Marine Dock, an engine is run at virtually wide-open throttle for 300 h straight during 60-min cycles (55-min wide-open throttle/5 min idle). According to GM, this testing is more severe than the standard durability testing used for truck applications.

GM, Fountain Powerboats, and Mercury MerCruiser jointly developed a concept boat, VX6, to demonstrate the capability of the newly marinized engine. The VX6 is a competition version of the latest edition 11-m (35-ft) Lightning Sport Boat that features two enhanced Vortec 6000 engines with a total output of 445 kW (600 hp) at 6000 rpm and 680 N?m (500 lb?ft) at 4000 rpm. The VX6 can reach speeds of more than 160 km/h (100 mph).

 

[mylesm260]

Re: Wow... The gen 4 small blocks are REALLY getting cheap!

Sweet!

I found a supplier who sells manifolds for them!

they're for PCM engines, but they have a separate manifold and riser.

Winter project here I come!