Team ZR-1 Corvette Racers
Custom Tuning
>Enter Here
Test and Tune
Common Information
IMSA 12 Hours of Sebring 2024
by teamzr1. 03/25/24 10:39 AM
Onstar means OnSpy
by teamzr1. 03/20/24 11:09 AM
Corvette Racing History
by teamzr1. 03/13/24 03:34 PM
If you cannot afford a C8 ZO6 - Than Steal One
by teamzr1. 03/12/24 03:47 PM
C8 Used Prices dropping like a Log
by teamzr1. 03/11/24 08:17 PM
IMSA 12 Hours of Sebring March 16th
by teamzr1. 03/07/24 08:48 AM
WEC Season Starts Feb 28th
by teamzr1. 03/02/24 01:24 PM
Newer Corvettes
Teammate Jason does 140 MPH in standing 1/2 mile
by teamzr1. 03/25/24 06:05 AM
C8 Corvette Convertible Water Leak
by teamzr1. 03/21/24 11:41 AM
GM Raises Extended Warranty Prices 30%
by teamzr1. 03/13/24 03:21 PM
Tech Talk
Stiffer Laws for Stealing CATs
by teamzr1. 03/12/24 05:14 PM
Forum Statistics
Forums27
Topics3,423
Posts6,135
Members50
Most Online265
Jan 21st, 2023
Previous Thread
Next Thread
Print Thread
Rate This Thread
#1153 - 12/24/06 10:49 PM 2007 “LS7” 7.0L V8  
Joined: Dec 2000
Posts: 5,268
teamzr1 Offline
Owner - Pays the bills
teamzr1  Offline
Owner - Pays the bills
Lives in Engine Bay

Joined: Dec 2000
Posts: 5,268
America
2007 “LS7” 7.0L V8 ( LS7 )

7.0L CORVETTE V8 (LS7) CAR ENGINE
2007 Model Year Summary


Overview
The 7.0L LS7 V8 is a bundle of superlatives: the most powerful production small-block V8 ever; ditto the highest operating speed (rpm) ever; more torque than the high-performance V10 in Porsche’s Carrera GT or the V12 in Ferarri’s 575M Maranello.

In an emotional sense, the LS7 connects the Corvette to its glorious past. Its 7.0-liter displacement translates to 427 cubic inches, identical to one of the most revered engines in racing and automotive lore—the original 427 Corvette big block. In a cold factual sense, the LS7 delivers a combination of attributes few engines—perhaps no engine--can match. It combines very high horsepower, torque and world-class race track performance with refined, tractable, rock steady operation on the street. Measured by mass, package size, performance or cost to the customer, the LS7 V8 meets or surpasses the best overhead cam V8s in the world.

The starting point for the LS7 was the first engine built for the fifth-generation Corvette—the Gen IV 6.0L LS2 V8. The LS2, in turn, had built on two milestone engines: the LS1 and LS6 V8s developed for the C4 Corvette. Those Gen III engines had introduced a host of leading-edge technologies to the grand tradition of the Chevrolet small block V8, starting with all-aluminum construction, a thermoplastic intake manifold and drive-by-wire electronic throttle.

The LS7 development team applied a number of design elements and technologies introduced and validated in the Corvette C5R road-racing program. To increase displacement, both bore and stroke were increased compared to the LS2--104.8 mm and 101.6 mm, respectively, versus 101.6 mm and 92.0 mm of the 6.0L Corvette V8. As a result, the LS7’s cast iron cylinder sleeves are pressed into, rather than cast in, the aluminum engine block. LS7 pistons feature tapered wrist pins to reduced weight. The piston rings are anodized to reduce blow-by and friction, while the skirts are coated with a polymer material to limit bore scuffing and reduce noise. Titanium connecting rods weigh 464 grams each or 27 percent less than the rods in the 6.0L LS2. The lighter rods reduce the pressure on the rod end bearings and the main bearings, and allow the bearings to be optimally sized for the least amount of friction. Six-bolt, doweled-in, forged steel main bearing caps hold the balanced crankshaft in place and reduce crank flex. The weight trimming, friction-reducing features in the LS7’s bottom end lower reciprocating mass and contribute to its 500-rprm maximum speed increase (7100 rpm fuel shut-off) compared to the LS2.

The old hot-rodding axiom about air in, air out applies to the LS7. The extra displacement would mean little in terms of horsepower if the engine could not draw in and then expel enough air to take advantage. To that end the LS7 is fitted with all-new cylinder heads. Fully CNC-machined intake and exhaust ports and combustion chambers reduce flow restrictions; the high machining consistency also allows a higher compression ratio. Valve angles are decreased to 12 degrees, compared to 15 degrees in the 6.0L LS2. The rocker arm ratio increases from 1.7:1 to 1.8:1 ratio. Low-friction hydraulic roller lifters actuate the valves, operated by the highest lift cam in Powertrain’s production vehicle inventory. Valves are larger and taller than those in the LS2, with titanium intake valves and hollow stem, sodium-filled exhaust valves to optimize heat transfer away from the valve face.

The intake system benefits from similar part-by-part review and refinement. The result is a 20-percent decrease in flow restriction compared to the LS2. The LS7 intake manifold is three-piece friction-welded composite, with large straight intake runners designed to maintain fast airflow velocity. Maximum air-flow volume increases 18 percent over the LS2. The filter element is supplied by Donaldson Company, Inc., known for high-performance racing filters.

The exhaust manifolds are stainless steel—slipperier and lighter than cast iron—hydroformed into a unique 4-into-1 collector designed to maximize flow. Exhaust pipes on the LS7-equipped Corvette Z06 are three-inches in diameter, compared to the 2.5-inch pipes on Corvettes built with the 6.0L LS2. The LS7 mufflers contain a butterfly valve that opens at high exhaust flow levels and by-passes the “tri-flow” S-shaped path the exhaust gases normally follow. This reduces exhaust restriction, yet allows the Corvette Z06 to hum at a more muted burble during part-throttle operation (or typical back-and-forth driving).

To ensure the 7.0L LS7 V8 operates at peak, low-friction efficiency, and to promote durability during extended high-rpm use under high cornering loads, the engine is equipped with a racing-style dry sump lubrication system and dual-gerotor oil pump. The first stage of the pump scavenges the small sump under the engine and delivers it to an eight-quart, remotely mounted reservoir. The second stage collects oil from the reservoir and sends it under pressure to the engine. The oil cools slightly in the reservoir, and then cools again in an air-to-oil cooler after it is collected by the second stage of the pump.

If its capability and high-speed potential seem to suggest otherwise, the LS7 nonetheless requires minimal maintenance. Its advanced iridium-core spark plugs and Dexcool coolant are validated to 100,000 miles of operation, with the same level of performance at 90,000 miles as they deliver at 10,0000. The LS7 also features an oil-level sensor and GM’s advanced Oil Life System. This technology measures stress on the engine and calculates oil life based on real-world use rather than a predetermined mileage interval. It eliminates unnecessary oil changes in vehicles that are driven in light duty conditions.

For all the improvements and advanced technologies built into the 7.0L LS7 V8, the bottom line still counts most. This is an ultra-high performance engine, with capabilities suited to one of the best performing sports cars in the world. It takes a back seat to no V8, blurring the line between overhead-cam and pushrod-actuated technology to the point where the distinction is meaningless—except for the relative cost advantages the pushrod engine delivers to both corporation and customer.


Team ZR-1
True Custom Performance Tuning
Teamzr1.com
Team ZR-1 Store
Enter Here
#1154 - 12/24/06 10:55 PM Re: 2007 “LS7” 7.0L V8  
Joined: Dec 2000
Posts: 5,268
teamzr1 Offline
Owner - Pays the bills
teamzr1  Offline
Owner - Pays the bills
Lives in Engine Bay

Joined: Dec 2000
Posts: 5,268
America
2007 "LS7" 7.0L V8 ( LS7 ) Car
Type: 7.0L Gen IV V8 Small Block
Displacement: 7008cc (427.6ci)
Compression ratio: 11.0:1
Valve configuration: overhead valves (2 valves per cylinder)
Assembly site: P.B.C. Wixom, Mi.
Valve lifters: hydraulic roller
Firing order: 1 - 8 - 7 - 2 - 6 - 5 - 4 - 3
Bore x stroke: 104.775 X 101.6
Fuel system: sequential fuel injection
Fuel Type: Premium Fuel required
Application: Horsepower: hp ( kw )
Chevrolet Corvette Z06 505 HP ( 377kw ) @ 6300 RPM ( SAE CERTIFIED )
Application: Torque: lb-ft. ( Nm )
Chevrolet Corvette Z06 470 lb-ft ( 637Nm ) @ 4800 RPM ( SAE CERTIFIED )
Fuel shut off: 7100 rpm
Emissions controls: catalytic converter
three-way catalyst
positive crankcase ventilation
MATERIALS
Block: cast aluminum
Cylinder head: cast aluminum
Intake manifold: composite
Exhaust manifold: Stainless Steel
Main bearing caps: Forged steel
Crankshaft: Forged 4140 steel
Camshaft: hollow steel
Connecting rods: Forged Titanium
Additional features: extended life spark plugs
Ti Intake Valve
extended life coolant
oil level sensor
Oil Life System


Team ZR-1
True Custom Performance Tuning
Teamzr1.com

Moderated by  teamzr1 

Who's Online Now
0 registered members (), 23 guests, and 7 spiders.
Key: Admin, Global Mod, Mod
What's New
Teammate Jason does 140 MPH in standing 1/2 mile
by teamzr1. 03/25/24 06:05 AM
C8 Corvette Convertible Water Leak
by teamzr1. 03/21/24 11:41 AM
IMSA 12 Hours of Sebring 2024
by teamzr1. 03/14/24 07:15 PM
No warranty Flipped Z06 now needs costly repairs
by teamzr1. 03/14/24 02:29 PM
Corvette Racing History
by teamzr1. 03/13/24 03:34 PM
Popular Topics(Views)
Techie
Teammate Jason does 140 MPH in standing 1/2 mile
by teamzr1. 03/25/24 06:05 AM
C8 Corvette Convertible Water Leak
by teamzr1. 03/21/24 11:41 AM
GM Raises Extended Warranty Prices 30%
by teamzr1. 03/13/24 03:21 PM
Stiffer Laws for Stealing CATs
by teamzr1. 03/12/24 05:14 PM
Powered by UBB.threads™ PHP Forum Software 7.6.0