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Inside the Boost-Ready LSX Crate Engine

Factory Pressure

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We've been trying to find the horsepower limits of the LS engine since the first supercharger kit for the 1998 Camaro, and we're not the only ones. Chevrolet Performance's Performance Marketing Manager Jamie Meyer has been watching customers pump copious amounts of boost into their racing efforts as well. With the direction of performance engineer Rocko Parker, Meyer and the team in the performance department developed a series of boost-ready engines for the Chevrolet Performance 2013 crate engine program.

The new bullets are called the LSX376-B8 and B15. You might already be aware of the LSX name for its heavy-duty block architecture that sources claim will withstand the forces generated by 2,000 hp. The number 376 is the cubic-inch displacement (6.2L) of the Corvette/Camaro LS3. The little B is for 8 pounds of boost, and the big B is for 15 pounds of boost. The critical area in a boosted application is "keeping the cylinder heads sealed," Parker says. "We are not pushing any limits, but because these long blocks carry a two-year warranty, we recommend staying at or below 15 psi."

Speaking of pushing the limits, we've had our hands on an LS3 crate engine for more than five years and relied on the aftermarket to supply us with stroker cranks and dished pistons to get the factory 10.7:1 compression ratio down to something we could supercharge. We found a stroked LS3 could make 600 rwhp easily using only 6 pounds from an Edelbrock E-Force Supercharger on pump gas and still fit under a Chevelle or Camaro hood. Using turbos, it made more than 1,000, but we had to take the engine apart and upgrade the rotating assembly to do it. Stories of the engine's exploits can be found at CarCraft.com when you search for "Late Crate Update" by freelance contributor Richard Holdener.

The B15 is different. It is factory engineered for amazing boost abuse, possibly beyond what our bolt-on twin-screw and Roots toys can generate. The core of the engine is the iron LSX block with Siamesed 4.065 bores that can handle 4.200 inches and a crankcase that can handle as much as 4.250 stroke, making it similar to the LS7 block (427-inch Corvette Z06). It has the same deck height as the LS3 at 9.240 inches, so your Camaro or Corvette goodies bolt on, and it is the only cast-iron 6.2L block. Similar factory supercharged engines like the LS9 (Corvette ZR1) and LSA (Cadillac CTS-V) are made from aluminum. Metallurgy aside, what sets the LSX block apart is the additional clamping force on the head gasket provided by eight additional head bolts, something you won't find on either the factory supercharged LSA or LS9 engines. In addition, the LSX has a thicker deck, six-bolt dowel-located billet main caps, and provisions for trick racing parts like motor plates, dry sumps, and mechanical cams. Think of it as all the best parts from all the supercharged factory engines in one package.

The rotator is also an improvement over the LS3. All LS engines have nodular iron cranks, except the LSA, LS7 (427-inch Corvette), and LS9. The B15 shares the crankshaft part number with the LSA supercharged Cadillac engine. It is made from forged steel and has a 3.62-inch stroke. The 6.098-inch rods are forged powdered metal from the LS3. The pistons are 4.065-bore, 4032 aluminum forgings with a 14cc dish that lowers the compression ratio to 9.0:1. They have a skirt coating and forced pin oiling for longevity.

That is a lot of alphabet soup. Let's review: You get an iron LSX block, an LSA supercharged crankshaft with good rods and forged pistons, special LSX/LS3 heads with an additional two bolts per cylinder, a cam, a balancer, a valvetrain, and valve covers, assembled from the factory for less than $8,000. That price is going to be hard to beat.

If you are going to run less than maximum boost, you can also buy the B8 for about $2,000 less. The primary difference is the cylinder heads. The B8 uses standard four-bolt-per-cylinder LS3 heads, forged powdered metal rods, and a nodular iron crank like the one in the LS3. You still get the same LSX block and forged pistons. The B8 is a lot more like the kind of engines we build here at Car Craft. Chevrolet Performance spent the money where it counts. The B8 should make a reliable 600–650 hp with 8 pounds of boost. The B15 should make 800–850 hp at 15 pounds. We also have the 3.5-inch Whipple pulley that makes 22 pounds. That should be good for more than 1,000—on paper, anyway.

Baseline

Using a factory LS3 manifold, the out-of-the-box B15 made almost 480 hp. The mild cam and non-ported heads kept it under 500. We aren't going to change a thing; instead, we are going to hit it with the Whipple then a set of turbos to see if 1,500 is possible from an engine you can buy from the factory.

RPM TQ HP
3,200 356 217
3,400 363 235
3,600 379 260
3,800 394 285
4,000 407 310
4,200 422 337
4,400 433 362
4,600 441 386
4,800 444 406
5,000 446 424
5,200 446 441
5,400 443 456
5,600 438 467
5,800 430 475
6,000 419 479
6,200 405 478
6,400 390 476
6,500 384 475

LSX BLOCK QUICK SPECS
Type 6.2L Gen IV small-block
Bore x stroke 4.065 x 3.622
Compression 9.0:1
Block LSX cast-iron
Cylinder heads Cast-aluminum, rec port six-bolt LSX/LS3
Valve diameter (intake/exhaust) Hollow stem 2.16-inch/solid stem 1.59-inch
Valvespring height 1.8
Chamber volume 70cc
Crankshaft Forged steel undercut and rolled rod/main pins
Main pin 2.56-inch
Rod pin 2.10-inch
Connecting rods Powdered metal w/ bronze small end
Pistons Aluminum forged 4032 (14cc dish)
Rings Solid steel top ring; cast-iron second; 0.025 ring gaps
Wristpin Full-floating 0.943 diameter
Camshaft Hydraulic roller 210/230 at 0.050 w/ 0.560/0.555-inch lift (intake/exhaust)
Rocker arm ratio 1.7:1
Oil 5W30 Mobil One
Maximum engine speed 6,500 rpm
Firing order 1-8-7-2-6-5-4-3

PARTS LIST
Description Source PN Price
105mm throttle body Accufab F105 $349.99
4.0L supercharger Whipple Superchargers WK-19060 6,499.99
Bolt kit Milodon 85002 9.25
F-body balancer ATI Performance Products 917242 435
Flywheel McLeod 460538 425
Headers Hooker 2471-1HKR 449
LSX B15 Chevrolet Performance 19299306 7,796.99*
LSX B8 Chevrolet Performance 19171049 5,979.97***
LS1 installation adapter Precision Performance Products N/A 15
Oil filter Penske Cadillac 89017524 8.08
Oil Filter Kit Milodon 21575 195.97**
Oil pan Milodon 30915 344.97**
Oil pan gasket Penske Cadillac 12612350 39.87
Oil pickup Milodon 18290 79.97**

*Price from Jegs.com
**Price from SummitRacing.com
***Price from Scoggin-Dickey.com

SOURCES
Summit Racing
Akron
OH
800-230-3030
330-630-0240
www.summitracing.com/
Chevrolet Performance
800-450-4150
http://www.chevroletperformance.
com
Whipple Superchargers
3292 N. Weber
Fresno
CA  93722
559-442-1261
www.whipplesuperchargers.com
Milodon
2250 Agate Ct.
Simi Valley
CA  93065
805-577-5950
www.milodon.net
JEGS
101 JEGS Place
Delaware
OH  43015
800-345-4545
www.jegs.com
Precision Performance Products
Cerritos
CA
5-62/-402-1108
www.precisionperformance.com
Holley Performance Products
1801 Russellville Rd.
Bowling Green
KY  42101
270-781-9741
www.holley.com
Accufab Racing
1326 East Francis St.
Ontario
CA  91761
909-930-1751
www.accufabracing.com
ATI Racing
6747 Whitestone Road
Baltimore
MD  21207
1-877-298-5039
http://www.atiracing.com
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48 comments
Flavio Leon
Flavio Leon

Exactly!!! u gotta laff at the haters not only are they way off on that fact...but if u dont like superchargers then dont post on a supercharger setup!!! lol !!!

Reginald Walker
Reginald Walker

Nice!! Im trying to decide the right upgrade to my 68SS. Going from 9+ Demon carb to Super charger. 454 chevy bored to 570 ci. Just want to do different with the super charger

Daniel Jones
Daniel Jones

So people think its easy power but you still have to build the crap out of your motor to be able to handle all the punishment a supercharger will give it.

Kyle Mack
Kyle Mack

Why waste the money strapping a supercharger to a 4 litter makes No sense plus the fact that all that power is unfortunately not doing anything for the car

David Ormsby
David Ormsby

A supercharged V8 funny car has 6000 horsepower and will do the 1/4 mile in 4.5seconds at 330mile an hour or 510 kmh, you could give a formula 1 car a 1/2 track head start and still beat it by 1 second. But funny cars dont last long and can't turn corners.

David Ormsby
David Ormsby

Superchargers are back big, time new technology have made them more efficient while creating more pressure while using less horsepower to run them than the old Superchargers did.love it .

Dan Edwards
Dan Edwards

Another LS? YAAAAAAAAAAAAAAAAAAAAAAAAAWWWWWWWWWWWNNNNNNN!

Jay Rey
Jay Rey

Ready to go in my pick up

Cory Conway
Cory Conway

Give me,give me, give me, give me,give me! Please. I said please

Shaun Townsend
Shaun Townsend

Hey Michael hey mike hey mike, guess what day it is! Blown lsx day!!

Greg Reinarts
Greg Reinarts

I run a Ford Racing 521 with a Hampton 871 blower on it, incredible power.

Joshua Pugh
Joshua Pugh

I don't do boost it's easy power so you get 500-1000 so what? You bought it. I could throw one on the 4.6 in my truck and make 600 easy but it's not me. Naturaly Asperiated ALL the way. Me and my brother Morgan Pugh are going to build a 460 this summer and might end up having to finish it next summer. We know we likely won't make it but our goal is 800+ Horsepower and 800+ torque but if we get anywhere close to that we will be happy. And that is something we could truly call ours and be proud of.

John Lawrence
John Lawrence

Would like to get my hands on her main bolts lol

Dean Henderson
Dean Henderson

another reason I dropped CC. Who can afford something like this....?

Travis Womack
Travis Womack

They finally made more power than the mustangs 5.8.....

Robert Hall
Robert Hall

Ill rip three of them whipples inna 87 fox body.. to hell with 1000hp im goin for 3k

Jon Heslekrants
Jon Heslekrants

Sven-Olof Boman Ryen 376 is the 6.2L LS3 displacement, the SC is 4.0L. This is one bad to the bone engine!

Michael Horner
Michael Horner

The 4.0L is the size of the supercharger. I'll take two please.

Scott Alno
Scott Alno

Can put my van 1988 chevy fullsize?

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