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M8 143 Custom CP Piston Kit

$975.00

When you're building a 143" M8 the right way, the piston isn't an afterthought. It's the foundation.

These are custom-spec CP-Carrillo Pistons, forged and machined to our exact specifications for the 4.500" bore × 4.500" stroke platform. Zero CC dome. +4 valve pockets. Under-head lightened. Vertical gas ports. Every detail engineered for one thing: making reliable, repeatable power at the compression ratios a serious 143" build demands.

These pistons were developed alongside our WP143 and WP143S camshafts and our +4mm Ward CNC ported heads.

What's Included:

  • Forged CP-Carrillo Pistons: Custom Ward Performance spec, zero CC dome, 4.500" bore.

  • Ring Pack: .043" steel gas nitrided top ring, .043" steel Napier backcut 2nd ring (THG), 3.0mm low tension oil ring

  • Wrist Pins: .927" × 2.500", .180" wall, 5100 chrome moly, chamfered for wire locks

  • Wire Locks: .927" × .073" circlips

  • Calico CT3 Coated Skirts: Applied by CP for reduced friction and scuff resistance

  • Vertical Gas Ports: Machined by CP

  • Ring gaps pre-set by us on a precision diamond ring filer. Bolt them in and go. No hours at the bench with a file and feeler gauge.

  • Proudly Made in the USA.

When you're building a 143" M8 the right way, the piston isn't an afterthought. It's the foundation.

These are custom-spec CP-Carrillo Pistons, forged and machined to our exact specifications for the 4.500" bore × 4.500" stroke platform. Zero CC dome. +4 valve pockets. Under-head lightened. Vertical gas ports. Every detail engineered for one thing: making reliable, repeatable power at the compression ratios a serious 143" build demands.

These pistons were developed alongside our WP143 and WP143S camshafts and our +4mm Ward CNC ported heads.

What's Included:

  • Forged CP-Carrillo Pistons: Custom Ward Performance spec, zero CC dome, 4.500" bore.

  • Ring Pack: .043" steel gas nitrided top ring, .043" steel Napier backcut 2nd ring (THG), 3.0mm low tension oil ring

  • Wrist Pins: .927" × 2.500", .180" wall, 5100 chrome moly, chamfered for wire locks

  • Wire Locks: .927" × .073" circlips

  • Calico CT3 Coated Skirts: Applied by CP for reduced friction and scuff resistance

  • Vertical Gas Ports: Machined by CP

  • Ring gaps pre-set by us on a precision diamond ring filer. Bolt them in and go. No hours at the bench with a file and feeler gauge.

  • Proudly Made in the USA.

Full Specs:

  • Bore: 4.500"

  • Stroke: 4.500"

  • Dome Volume: Zero CC dome

  • Valve Pockets: +4mm

  • Weight: 637g per assembly

  • Skirt Coating: Calico CT3 (applied by CP)

  • Gas Ports: Vertical

  • Under-Head: Lightened / milled

Wrist Pins:

  • Diameter: .927"

  • Length: 2.500"

  • Wall Thickness: .180"

  • Material: 5100 Chrome Moly

  • Retention: Wire locks (.927" × .073" circlips)

  • Pin Fitting: Done by CP

Ring Pack:

  • Top Ring: .043" steel, gas nitrided, 4.505" bore

  • 2nd Ring: .043" steel, Napier backcut, THG, 4.505" bore

  • Oil Ring: 3.0mm low tension, 4.500" bore

Compression:

At .040" piston-to-head clearance

  • 92cc chamber: 12.44:1

  • 90cc chamber: 12.67:1

  • 88cc chamber: 12.90:1

  • 86cc chamber: 13.15:1

  • 84cc chamber: 13.41:1

  • Choosing the right compression ratio for your build, or pairing these pistons with the right cam and head combination, is what we do. Contact us and we'll get you sorted.