While the version pictured is for the GM LS7 engine, Summit Racing has timing set options for every 1997-2015 Gen 3 and Gen 4 LS motor that’s running a 3-bolt performance cam. (Image/Summit Racing)

Timing Chains are one of the most critical components in an engine. On one side you have the 57-pound crankshaft feeding near-instantaneous acceleration and deceleration loads from idle to redline. On the other end you have a nine-pound cam and sixteen lifters, pushrods, rockers, springs, retainers, and valve locks that must be kept in perfect harmony.

All of that weight, plus a few thousand pounds of combined spring force, is a lot of mass to control at 7,000+ rpm.

And while you know that a Chevrolet LS engine loves more camshaft, you still have to keep it all in sync.

Turns out, there’s an easy way and a hard way to do it.

  • The Hard Way: Double-roller timing chains are strong but don’t fit behind the oil pump and timing cover without spacers and grinding.
  • The Easy Way: Premium, American-made Summit Racing Pro LS Billet Timing Chain Sets. These single-roller chain sets use an extremely high-quality roller chain for the ultimate in durability.

But these timing sets don’t just solve your timing problem, there are plenty of other reasons why you’d want to use one on your LS project:

  • Made from precision machined billet to exacting tolerances.
  • Precisely balanced with weight reduction holes to offset the weight of the 1x or 4x poles on the front of the timing gear. This reduces chain whip at high rpm for more accurate timing and less wear.
  • Available in 1X and 4X versions for all Gen. 3 and 4 (1997-2015) LS engines utilizing a 3-bolt performance camshaft. LS7-specific sets are available as well.
  • Available in standard, -.005 in. and -.010 in. lengths for align-honed blocks.
  • They’re adjustable, with included captured color-coded degree bushings to advance or retard the cam in two-degree increments for a total of eight degrees either way. The crank sprocket is adjustable in four-degree increments too.
  • Solve piston to valve clearance issues without the need to fly-cut pistons. Advancing the cam adds exhaust clearance. Retarding the cam increases intake clearance.
  • Micro-finished pins reduce friction for more horsepower and reduced wear.
  • They’re continuously tested for hardness, tensile strength, and dyno performance to ensure quality.
  • Upper gears are available separately. They’re compatible with common OE-style LS2 replacement timing chains.
  • Dampers and damper bracket kits are available for the early Gen. 3 engines that offer even more stability and durability.

These Pro LS Timing Chain Sets and Gears are part of Summit Racing’s growing Pro LS line of engine components initially introduced in 2018. Since its launch, the Pro LS lineup has continued to expand and includes forged pistons, rods, and cranks, along with a large selection of camshafts and valvetrain parts.

Here’s a complete list of part numbers and applications for the Summit Racing Pro LS Timing Gear and Chain Sets.

Summit Racing Pro LS Timing Gears & Gear Sets

Part NumberPart
Type
LS Engine ApplicationCamshaft Gear, BoltLength
SUM-G6643-1XTiming GearLS Gen 3
& Gen 4
1X, 3-BoltStandard
SUM-G6643-1X-005Timing GearLS Gen 3
& Gen 4
1X, 3-Bolt-0.005" Line Hone
SUM-G6643-1X-010Timing GearLS Gen 3
& Gen 4
1X, 3-Bolt-0.010" Line Hone
SUM-G6644-4XTiming GearLS Gen 44X, 3-BoltStandard
SUM-G6644-4X-005Timing GearLS Gen 44X, 3-Bolt-0.005" Line Hone
SUM-G6644-4X-010Timing GearLS Gen 44X, 3-Bolt-0.010" Line Hone
SUM-G6645-1XTiming SetLS Gen 3
& Gen 4
1X, 3-BoltStandard
SUM-G6645-1X-005Timing SetLS Gen 3
& Gen 4
1X, 3-Bolt-0.005" Line Hone
SUM-G6645-1X-010Timing SetLS Gen 3
& Gen 4
1X, 3-Bolt-0.010" Line Hone
SUM-G6647-4XTiming SetLS Gen 44X, 3-BoltStandard
SUM-G6647-4X-005Timing SetLS Gen 44X, 3-Bolt-0.005" Line Hone
SUM-G6647-4X-010Timing SetLS Gen 44X, 3-Bolt-0.010" Line Hone
SUM-G6649-4X-LS7Timing SetLS74X, 3-BoltStandard
SUM-G6649-LS7005Timing SetLS74X, 3-Bolt-0.005" Line Hone
SUM-G6649-LS7010Timing SetLS74X, 3-Bolt-0.010" Line Hone
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Author: Brian Nutter

After a stint in the U.S. Air Force, Brian Nutter studied at the Houston, TX-based School of Automotive Machinists in 1997. The early part of his automotive career included working for engine builders Scott Shafiroff and C.J. Batten, followed by several years developing performance pistons at Wiseco Piston Co. Today, Brian develops performance parts for Summit Racing Equipment and is a regular OnAllCylinders contributor. For fun, he runs his 427-powered C5 Z06 in ECTA land-speed racing, at OPTIMA® street car events, and at a mix of autocross, drag racing, and track days.