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Discussion Starter · #1 ·
The vehicle is a 68-72 Old Cutlass in DuSold Designs for a Pro-Touring makeover. The engine is the LSX376-B15 and I think it's a Magnuson Heartbeat 2650? Can you identify the supercharger (2300 or 2650 Hearthbeat) and which of the multitude of applications this was made for? The shop says the expectation is 700 to the wheels on a DynoJet at ADM. Is that realistic with the engine rated to a max of 15 pounds of boost?

If you were to purchase a LSX376-15 wouldn't you at least change out the powdermetal connecting rods; or is something else in that rotating assembly causing GM to state 15 pounds of boost max? In my application having to go dry sump the GM forged crank would go and a LT4 forged crank (or other dry sump crank) would replace it. At that point you begin to wonder if it's just better starting with a Dart LS Next block and the LSX-LS3 6-bolt heads on the engine and buying a balanced rotating assembly?
 

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that is a 2300 heartbeat
with good cam and fuel 700 will be easy. 900 isnt out of the question if you wanted to push it

as for engine , why buy a long block complete to just rip it apart? its pretty much an lsa in a lsx block. so 15 psi easy but have seen them take much more.

If you wanted a custom engine , then best to have a pro builder do it to your specs.

and lt and ls stuff is different so your comparing apples to oranges.

once you price the dart block with heads and all parts , youll be quite a bit more $$$$ than the b15
 
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Discussion Starter · #3 ·
-What identifies it as a 2300 Heartbeat versus a 2650? Is it the height, fuel rails; etc?
-What application (Vette, CTS-V, truck; etc.) was this unit for?

I ask as I am considering the Heartbeat for my build which is a '77 Pontiac Lemans (CanAm). The size isn't so much about total power or even power under the curve but rather about overall efficiency. Would the 2650 version and its increased volume (no idea if the cooling bricks are bigger) provide better cooling for endurance/road racing? I recognize it takes more power to drive the 2650; the goal is to optimize cooling with lower boost levels while running 700-800 rear wheel on 93 octane. if the supercharger cools runs cooler and I can rely on one large C&R front intercooler versus having to add additional twin side intercoolers it will reduce the expense and complexity involved in my Pro-Touring build.

As to the B-15 in my application, I learned a Dailey dry sump will fit on an LS wet sump application, and I think Wegner has a front drive (with AC) for it? If the B-15 will endure that type of racing; then you are correct; building a custom engine will be much more expensive and unnecessary. I would rather upgrade to a better dry sump system than spend it on a long snout dry sump rotating assembly which takes me down the custom build path.
GM LS Production Right Side | Dailey Engineering
 

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Both those maggies look beautiful.
 

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that is a 2300 heartbeat
with good cam and fuel 700 will be easy. 900 isnt out of the question if you wanted to push it

as for engine , why buy a long block complete to just rip it apart? its pretty much an lsa in a lsx block. so 15 psi easy but have seen them take much more.

If you wanted a custom engine , then best to have a pro builder do it to your specs.

and lt and ls stuff is different so your comparing apples to oranges.

once you price the dart block with heads and all parts , youll be quite a bit more $$$$ than the b15
Just to add to your info above:
B-15 uses same crank and con rods as does LSA, and is warranted to 900 fwHP.
Pistons are forged and cam is different.

Take care Chase!
Bruce
 

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Discussion Starter · #9 ·
Thanks to all; what's interesting is it seems the Magnuson Magnum 2650 has the same basic height as the Heartbeat 2300 (which is almost identical to the LSA and Kong 2650, but slightly taller than the ZR1 2300). If my goal is 725-750 rwhp with the most efficient supercharger (design of rotors, efficiency of bricks) with large enough port volume and efficient cooling is there a road racing front-runner?

Assumptions: It's on the B-15 long block and I have ample room for a large front intercooler and runs 93-octance gasoline (I have no desire to run methanol, interchillers or racing gasoline). I will consider a couple of gallons of E-85(add DSX flex fuel kit) only as a way to spike the inconsistent nature of 93-octane in Texas. Street use 50% and road racing 50% in conditions between the Dallas, Austin, Houston triangle that see very hot conditions.

My take; certainly not based on real world experience:
1) ZR1 2300 with Matt's lid and C&R bricks
2) Magnuson Magnum 2650
3) Magnuson Heartbeat 2300
4) Kong 2650 with a non-Kong lid
5) LSA ported supercharger with Matt's lid and C&R brick.

Not in Contention: Kong Lid
 
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