CHEVY LS1 related info

Discussion in 'Blocks' started by grumpyvette, Nov 17, 2010.

  1. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    LS1 Engine Performance Build and Dyno Test
    Written by Jim Smart on September 18, 2017

    It can be safely said GM’s all-new LS1 opened the door to a new world of technology and performance in the 1990s. It can also be accurately stated the LS family is easily the most successful V-8 in American automotive history aside from the time-proven small-block Chevy, which remains in production 63 years later. We consider the LS engine something of a lesson in perfection—cathedral style intake ports, evenly spaced elliptical exhaust ports, fulcrum pivot rocker arms, a skirted cross-bolted block with a tall deck, steel crank, and a host of other great features. GM took all of the best attributes of the small-block Chevy and small-block Ford and rolled it all into the skirted LS. The LS has only gotten better with time and more advanced engineering, leading up to the LSX.

    To return to the original LS pushrod V-8 has been a privilege because this has enabled us to examine how far Chevrolet has come with this engine. If you’ve got a vehicle powered by the LSX you know what we mean. It is great fun working with such an incredible engine. Last time, we took you through the machining and build up of a 5.7L LS1 being built by L&R Engines just south of Los Angeles in Santa Fe Springs. These guys pay extreme attention to detail in all of their engine builds. You never know what you’re going to see at L&R Engines. Their work ranges from commonplace small-block Chevys and LS mills to Studebakers, Packards, classic Chrysler Slant Sixes, Detroit diesels, and more. If it sucks, squeezes, bangs, and blows L&R knows what to do with it.

    We have machined, cleaned, and assembled our LS1. Now for the home stretch of this project that includes a valve job and final completion, and a date with a Dynojet 902 at Westech Performance near Riverside, California. The beauty of the LS is its wonderful simplicity—two gorgeous aluminum castings stacked on top of a groovy skirted Y-block ready for just about anything you can throw at it.

    We wanted to dyno test this LS1 two ways: one with the FAST LSXR 102mm intake manifold designed for car applications like the Camaro, Chevelle, Nova, and Corvette and one with the tall Dorman or FAST LSXRT intake designed for truck and SUV applications. The difference in the two intake manifolds is clear. The FAST LSXR 102 manifold employs short runners designed for high-rpm horsepower and torque. The Dorman truck/SUV intake manifold turns its attentions mostly to low- to mid-range torque with less focus on horsepower. We were unable to test the Dorman or the FAST LSXRT intake because we weren’t able to source the appropriate fuel rails in time to meet deadline. However, we can tell you the Dorman OEM replacement intake with its long intake runners is engineered for raw twist in a truck. Ditto for the FAST LSXRT truck/SUV intake for LS vehicles with a higher hoodline.

    Let’s wrap this thing up.


    1. We’re working with the original LS1 cylinder head castings sporting 2.000-inch intake and 1.550-inch exhaust valves. We have replaced the valves and guides with Speed Pro parts and cut fresh seats. Chamber size is 66.67cc. We’re confident that with some good custom port and bowl work along with a hotter cam we would have pushed this thing closer to 500 horsepower.


    2. You’ve got to love the LS1’s cathedral intake ports, which were a quantum leap size-wise when they arrived in the late 1990s. It doesn’t take much to get power from these ports.


    3. LS1 exhaust ports sport a straightforward angle with a high ceiling, which means excellent scavenging. Perform a little port work and these guys will flow. We had to chase the spark plug holes, which had minor thread damage.


    4. When we began this LS1 build we threw all of the stock bolts in the recycle bin. If you want it bulletproof, you’ll have to opt for ARP fasteners throughout. We chased threads in the bolt holes and were sure to use a thread lubricant.


    5. LS engines sport lifter guides/holders, which drop right into place as shown. These hydraulic rollers from Comp have been lubricated with assembly lube.


    6. Fel-Pro head gaskets have been laid down on hospital-clean surfaces. We’re ready for the cylinder heads. It is virtually impossible to screw this up. Fel-Pro marks the head gaskets “FRONT” for easy lay-down.


    7. The cylinder heads were installed and torqued to specifications in proper order. Keep in mind that factory cylinder head bolts can’t be reused because they are torque-to-yield bolts. ARP bolts are not torque-to-yield and are torqued like conventional cylinder head bolts.


    8. The valvetrain is installed and torqued to proper specifications. Make sure the rocker tip is centered on the valve stem.


    9. Shown here is the stock harmonic damper, which is not what we installed in Part 1. We showed you the Summit Racing underdrive harmonic damper, which reduces accessory speed and frees up power. Harmonic damper selection depends on how you intend to use your LS1.


    10. We opted for a stock LS water pump, which we ordered from Rock Auto. No real preparation is necessary, just make sure the contact surfaces and the seals are clean before you bolt it on.


    11. The valve covers are installed next, incorporating Fel-Pro seals.


    12. FAST engineers teamed up with airflow specialists at RHS to develop polymer intake manifolds for GM LS engines. While the LSXR features a 102mm air inlet that is perfectly suited to the FAST Big Mouth 102mm throttle body, we’ve opted for the 92mm throttle body. Other features include integrated nitrous bungs and perfect bolt-on fitment that allows the use of factory accessories without modification or clearance concerns. We’re running 36 lb/hr FAST injectors, which will work fine with our 5.7L and a hot cam.


    13. Especially cool is this 92mm throttle body, ideal for street and strip, that arrives on your doorstep in a convenient protective carrying case (seriously!) packed in foam. FAST throttle bodies include an idle air control (IAC) solenoid and a throttle position sensor (TPS).


    14. Our completed LS1 at L&R Engines is ready to go on the dyno.


    15. Steve Brule of Westech Performance gets our LS1 ready for a series of pulls using the FAST system. Engine oil is added for the break-in.


    16. Our FAST LSXR 102mm intake manifold is installed and set up with 36 lb/hr injectors and FAST fuel rails.


    17. This handsome induction package netted us 447.8 horsepower and 434.6 lb-ft of torque.
  2. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

  3. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    List of intakes tested and reviewed:

    > Stock LS3

    > Stock LY6

    > Stock LS2 (with adapters)

    > FAST Adjustable LSXR (long runners)

    > FAST Adjustable LSXR (medium runners)

    > FAST Adjustable LSXR (short runners)

    > FAST Adjustable LSXRT (short runners)

    > Holley Mid-Rise EFI

    > Holley Mid Rise (dual 4150 TB)

    > Holley Hi Ram (105mm TB)

    > Holley Hi Ram (dual 4150)

    > Holley Sniper (low)

    > Holley Sniper (high)

    > Edelbrock Vic Jr.

    > Edelbrock Super Victor 4150

    > Edelbrock Super Victor 4500

    > Edelbrock Cross Ram

    > Mast 4150 Single-Plane

    > Speedmaster IR Downdraft

    In a separate test (415 stroker), but still compared to the stock LS3 intake:

    > Stock LS3 (415 stroker)

    > Edelbrock Pro-Flo XT LS3 (415 stroker)

    > Performance Design Carbon pTR (415 stroker)

    Last edited: Mar 4, 2018
  4. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member
    Greg Brown blankets a 416ci LS with Hemi heads to make 636 HP on pump gas.

    That’s the outrage we’d expect from the Mopar faithful or perhaps even the Ford hemi guys. After all, their righteous indignation is aimed directly at a set of hemi heads sitting astride an LS short-block.

    Allow that to stew in its own juices for a moment or two. Then ignore the automotive theologians and focus instead on the fact that hot rodding has always ridden on the knife’s edge of automotive heresy. It wasn’t all that long ago that hot rodders were reviled hooligans.

    Still, the two terms “hemi” and “LS” would seem to be mutually exclusive, except to Greg Brown. To him, the two were destined to partner up to create the unlikeliest of performance engines. Brown’s initial foray into the world of hemi heads began when he saw the need—long before perhaps there was a need—for a set of hemi heads on a small-block Ford. Emerging from a rather large pile of aluminum shavings, he presented the world a set of Hammerhead hemi castings banging valves up and down on a 351W and later a 427 Ford. That alone was cause for celebration, but Brown was already looking ahead.

    Being the creative guy that he is, it occurred to him one day that there was but a mere 0.020-inch difference in the bore spacing between a small-block Ford (4.380-inch) and GM’s LS engine (4.40-inch). This simple observation led him to drill a 10-bolt LS head pattern into a pair of castings and with a few other changes he had what he needed to bolt a set of Hammerheads on an LS engine. Aligning his ducks beak-to-tail wasn’t nearly as easy as that oversimplified description, but a good idea whose time has come is a force that cannot be ignored.

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    Brown has spent the past 18 months dealing with all the pesky minutiae required to make the valves go up and down without issues. He introduced his premiere hemi LS at the 2017 PRI show and HOT ROD was immediately intrigued. We put the pressure on him by recording the event as the LS hemi churned up the dyno for its maiden effort. But before we get to the sexy power numbers, let’s do the equivalent of automotive cave diving into those massive aluminum ports that started all this craziness.

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    Brown’s initial effort was aimed at building a set of hemi heads that would bolt directly to a small-block Ford. While the valve arrangement and the massive valve covers certainly exude hemi, looking at the chamber might lead you to think this is nothing more than a wedge chamber with big valves. According to Brown, that’s exactly what it is. “It’s really just a rotated wedge chamber.” But a near-centralized spark plug and wide canted valves pointed in make it look like a hemi. ‘Nuff said.

    The main advantage of this valve arrangement is that the valves open toward the center of the cylinder bore as opposed to wedge heads with inline valves that open toward the cylinder wall. The difference is all about flow. With a 2.20-inch intake valve, this head with Brown’s street-friendly 45-degree valve job will push the needle to 379 cfm on the intake side and 263 cfm on the exhaust side, both at 0.700 lift. And those are not the peak numbers; the intake can over-achieve beyond 400 cfm at 0.800-inch lift.

    This is what the hemi heads look like before they start producing some serious airflow. Brown discovered that his original Ford small-block hemi castings would also fit a large-bore LS3-style engine with a few tweaks.
    Brown says that he has several customers focused on turbo-boosting these castings. With porting and a larger valve, Brown has already achieved 470 cfm on the intake side. The combination of massive airflow with boost should be impressive.

    Of course, these expansive heads also require their own specific valvetrain. For this, Brown sought out Jesel’s assistance and all Hammerheads come with Jesel Professional series shaft rockers. For this LS engine, Brown fitted the heads with Comp beehive springs for the hydraulic roller cam.

    The Hammerhead intake port layout was originally designed to allow Ford Windsor intakes to bolt right on. We’ll get to how Brown solved that for the LS a little later. The exhaust ports were a bit more of a challenge with Brown settling on the Ford/Yates C3 layout. This allows an engine builder to at least buy the exhaust flanges to facilitate custom headers.

    These castings were treated to the same production valve job and valve sizes as any standard Hammerhead heads with no special port work added. Valve sizes are 2.200- / 1.65-inch valves with a 62cc combustion chamber.
    To begin this hemi LS odyssey, Brown’s initial customer, Ricky Tucker, wanted this unique combination stuffed into a Pro Touring ’69 Camaro. Brown started with a production LS3 block at a 4.165-inch bore and honed the cylinders another 0.005-inch and pumped the displacement with a 4.00-inch Lunati steel forged crank along with 6.125-inch Lunati H-beam rods.

    An effort like this does require some help from solid sources like the guys at Diamond who had already helped Brown with hemi pistons for his initial Ford effort. The pistons are really just a set of LS strokers with a crown configured to accommodate the hemi valve layout and larger 2.200-inch intake valves. Brown told us that bore spacing is measured from the center outwards. So the outboard valves would be skewed slightly inboard compared to a stock valve position on an LS engine.

    The castings also require a dedicated set of Jesel Pro aluminum rockers. The hemi valve layout requires the long exhaust rocker but with mild hydraulic roller camshaft valve timing, rocker deflection is minimal.
    For piston-to-valve clearance, Brown came up with a simple solution. While a standard valve relief pattern would supply a 0.050-inch radial clearance (given the 2.200-inch valve size) between the valve edge and the piston, that would become tighter with the outboard cylinders due to the hemi heads’ shorter bore spacing. So Brown had Diamond machine the valve pockets for a 2.250-inch valve diameter, creating the additional radial clearance.

    Brown says that while these Diamond pistons were custom machined and therefore expensive, he’s working with a couple of piston companies to come up with production parts that would be more affordably priced. For sealing, Brown went with a set of 1.5/1.5/3.0mm Total Seal ductile-iron top and Napier second ring set with a standard tension oil ring set.

    The next big hurdle was a bit more challenging. Brown’s Hammerhead castings reverse the normal LS valve layout, meaning that while an LS engine orients the valves starting with the intake while the hemi heads lead with an exhaust valve. This demands a re-oriented camshaft that reverses the intake and exhaust lobes. At the time, Brown had Comp Cams employ a billet LS cam core to create his camshaft. This clearly isn’t an off-the-shelf cam even though the specs are still very mild at 238/246 degrees at 0.050 with 0.595-inch lift on both the intake and exhaust ground on a 112-degre lobe separation angle (LSA).

    The biggest challenge was creating a manifold to meet his customer’s requirements. Brown chose a Chevrolet Racing SB2 manifold that he cut down the center, adding two 5/8-inch thick lengths of aluminum to create the proper width and runner positions.
    Interestingly, Brown later discovered almost by accident that the new Gen V LT1 and LT4 engines switched the valve orientation and now place the exhaust valve at the front of the chamber instead of the intake. He immediately recognized that he could use a Gen V cam blank for future LS hemi builds, saving considerable expense over a billet core. The Gen V engines use a single-bolt cam drive, but other than that, it is an easy retro-fit to any LS engine. Sometimes the world just delivers an unexpected present right to your shop door. Greg Brown must live right.

    But the challenges of building an LS hemi were far from resolved. The stock LS engine deck height is 9.240 inches while the Hammerheads were originally designed for either a short-deck Windsor at 8.206 or the taller 351W deck of 9.48. Since Brown had designed his original Hammerheads to accommodate either of the Ford intake manifolds, the LS presented a significant design impediment.

    This is the finalized manifold that is now a bolt-together two-piece manifold. Without the prior photo you’d never know this manifold had been extensively modified.
    His solution for this first LS hemi effort focused on a NASCAR restrictor-plate version of the SB2 intake. “That wasn’t my first choice, but the customer required that the engine fit under the flat, stock hood of a ’69 Camaro. That made it tough.” The restrictor plate version SB2 was a solid two inches shorter and provided the real estate to fit it with a Holley 1,000 cfm throttle body. But that doesn’t mean this intake bolted right up.

    When asked how much time he had invested in this intake, Brown just sighed and admitted he easily had over 40 hours in this casting just to make it fit. To start, he sawed it right down the middle, adding a pair of 5/8-inch thick plates. Plus, the customer wanted the engine to look carbureted, so the short, Deatschwerks 50-lb/hr injectors were placed on the inboard side of the intake runners. With the final welding of the now two-piece intake complete, it’s difficult to fully appreciate the effort that went into its creation.

    Brown says he’s initiated a plan with Tyler Hogan at Hogan’s Racing Manifolds to build a sheetmetal base for the LS hemi engines that would accommodate the multiple top half Holley castings that would allow both a single or dual four-barrel mount or a front-mounted EFI-style throttle body which will also make this a much more affordable induction. Brown said that if he had been able to use the taller manifold, the engine would have gained significant torque, but packaging constraints dictated the shorter version. All that means is there is plenty of power still available, given fewer tuning restraints.

    With the engine assembled, Brown delivered the engine to Pro Motor Engines in Mooresville, North Carolina where Dennis Borem and company bolted the hemi on the dyno while Holley’s Robin Lawrence lent his considerable tuning skills to the Holley HP EFI system. In a short period of time the wide-body LS churned out a peak torque of 545 lb-ft at 5,500 rpm and 636 hp at a very manageable 6,500. This is a 10.5:1 compression pump-gas engine that would run all day at these elevated numbers. Despite the large, single-plane intake and big-tube headers, this 416 was still capable of over 400 lb-ft even at 2,800 rpm.

    Even with all this innovation, Hammerhead prices a pair of these castings for a hydraulic roller cam at only $5,995. There’s far more to a complete engine of course, but not as pricey as first appears. So there you have it, LS irreverence on a grand scale that will soon find its way under the hood of a Detroit Speed-built ’69 Camaro. We can only imagine the questions that will crowd around the engine compartment every time Tucker pops the hood.

    From underneath, the rotating assembly is much more traditional LS with a Lunati 4.00-inch crank and Lunati H-beam 6.125-inch connecting rods.
    Of course, the hemi valve layout demands custom positioned valve reliefs in the Diamond forged 2618 pistons. The pistons also sport a 1.5mm/1.5mm/3.0mm ring pack.
    For this first engine, Brown used a tool steel billet core, but has since discovered that the LT1/LT4 Gen V LS camshaft core uses the same valve orientation so that cam family can now be used with the hemi heads. The lobes for the LT mechanical fuel pump will be unused. (Photo credit: Comp Cams)
    Brown positioned the LS7-style Deatschwerks injectors underneath the runners to give the manifold a cleaner look. Air is metered by a Holley 1,000cfm 4150-style throttle body.
    A Vintage Air front drive spins the accessories like A/C, water pump, alternator, and power steering. Brown added an Edelbrock water pump that required a small amount of machining and features a simple-to-replace impeller cartridge.
    It took Greg Brown (right) about 14 months to make the initial packaging happen for this hemi LS with help from Chester Armstrong (left).
    All the dyno testing was performed at Pro Motor Engines (PME) in Mooresville, North Carolina with help from Dennis Borem.
    Control over spark and sequential fuel was assigned to Holley’s HP EFI system.
    To make sure it all went smoothly, Holley’s Robin Lawrence made a trip to Mooresville to ensure that all the tuning was optimized.
    Available valve covers for the Hemi heads are black crinkle cast aluminum (as on this engine), Moroso-built aluminum sheetmetal, and bare cast aluminum (machined ribs optional).
    Brown uses Moroso early-style Mopar spark plug wires to connect between the stock LS3 coils and the normal, gasket-style Autolite 0.750-inch reach spark plugs.
    This underneath shot of the modified SB2 manifold shows the fuel rails and injector placement. This was done primarily for aesthetics and there potentially could be a slight power gain were the injectors moved higher on the runner.
    This is the manifold-side view of the intake port. It’s nearly a straight shot right to the back side of the valve.
    The exhaust port is as tall as practical and uses a readily available Ford/Yates/SVO exhaust flange layout.
    The headers are custom fabricated using a Yates flange. Also note the -8AN hose used as an oil return from the valve covers to the pan. Since LS engines do not feature a dedicated oil return, Brown says this ensures the oil is not captured in the valve covers.
    The original LS heads used two different length head bolts or studs. Ironically, the stud length Brown needed for the Hammerhead castings are exactly the same length as the longer of the two early head studs on the LS.
    This reveals a little more about how much effort went into making that SB2 manifold work. Each plate is 5/8-inch thick making the total spacer roughly 1.125-inch wide. Also note how Brown had to offset the ports to properly line up.
    This is the manifold in its finished form with the Holley 1,000cfm throttle body bolted in place.
    The cooling system routing remains the same, which necessitates plumbing these steam lines between all four corners of both heads and the radiator.
    For this mild hydraulic roller cam on the LS engine, Brown used Comp beehive springs with a 1.950-inch installed height and 150 lbs. of seat force. With Jesel rockers, pushrod length becomes critical since there is limited range of adjustment on the rocker.
    The Jesel Pro series rocker shaft system appears simple but there’s quite a bit of engineering that goes into these pieces. The rockers are available in half ratios from 1.60:1 to 1.85:1.
    Brown had to machine a custom valley cover for the engine with a chamfer along both lengths to clear the heads.
    Brown used the Holley HP EFI system to control spark and fuel on the engine with tuning help from Holley’s Robin Lawrence.
    This tight view of the Lunati crank and rod package reveals how much the pistons pull out of the bottom of the cylinder sleeves even with a 4.00-inch stroke. Brown used ARP fasteners for the main studs and rod bolts.
    Brown used a factory Corvette pan (PN 12624617) for the LS stroker along with a new ATI balancer that works in conjunction with the Vintage Air accessory drive. Studs make mounting the accessory drive much easier.
    Cylinder Head Flow*

    Lift: Intake: Exhaust:
    0.200 156 138
    0.300 225 178
    0.400 290 216
    0.500 339 240
    0.600 366 255
    0.700 379 263
    0.750 384 268
    0.800 390 275
    *Numbers are for a standard set of Hammerhead hemi heads. The heads were flowed using a test depression of 28 inches of water with the heads mounted on a 4.125-inch bore fixture.

    Cam Specs

    Intake: 238˚ at .050-inch lift
    Exhaust: 246˚ at .050-inch lift
    Valve lift: 0.595 inches
    LSA: 112˚

    On The Dyno

    RPM: TQ: HP:
    2,800 411 219
    3,000 422 241
    3,200 442 269
    3,400 469 304
    3,600 488 335
    3,800 493 357
    4,000 499 380
    4,200 502 410
    4,400 500 419
    4,600 509 446
    4,800 524 479
    5,000 535 509
    5,200 539 534
    5,400 543 558
    5,600 543 579
    5,800 539 595
    6,000 533 609
    6,200 525 619
    6,400 517 630
    6,600 462 581
    Avg.: 508.0 459.9
    Peak/rpm: 545 @ 5,500 636 @ 6,500
  5. Maniacmechanic1

    Maniacmechanic1 solid fixture here in the forum

    They are Ok Grumpy.

    If you ever price out the Goodies....

    They Just Look Better and I Love the Exhaust Sound of Both.
  6. Grumpy

    Grumpy The Grumpy Grease Monkey mechanical engineer. Staff Member

    yes, after reading through the article,
    yes the fabrication and engineering is impressive,
    I'm fairly sure that all the custom parts and fabrication would cost considerably more,
    than a serious BBC, that could be built at a similar cost to produce,
    considerably more power with less effort.
    before you go jumping head first off the financial dock,
    it logically pays to check the depth of the financial water,
    or put a different way, to carefully list and verify,
    what the projects net cost vs the time and effort would be?
    and what the resulting engines expected power and durability you could reasonably expect,
    so the fact you could or you can do something is not always an indication that the value per dollar spent will be worth the result.
    lets say you could duplicate that project and its results, if you could do it for under about $10K-$11K it might be worth the effort,if it cost $14-$15K plus, there are in my opinion, much better alternatives.
    if you check, youll find that engines like a SOHC ford 427 or a BOSS 429 or a Chrysler 426 hemi
    can easily be built to exceed 600 plus hp, as can a BBC, the issue is the cost per hp, and durability. a 496-540 BBC can easily be built to match or exceed the 600-650hp level at a lower cost than most of the others simply because performance parts are far more common and less expensive.

    just so others can look over the test results, on those ls intakes

    both cross sectional area, and length effect flow but remember, displacement compression and cam timing also are major factors.
    what most people fail to take into account is that the cam timing and exhaust scavenging being properly matched is critical.
    changing the cam timing or header configuration would change some of the resulting intake flow rankings

    Last edited: Aug 12, 2018 at 10:03 AM

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