Caterpillar 299-5204 Piston Assembly

Specifications

Part TypePiston assembly (piston body with pin and pin locks/clips)
Bore Size170 mm (Cat 3500-series long-bore piston)
ConstructionOne-piece steel piston with oil-gallery cooling and combustion bowl (per IPD/Reliance equivalents)
Pin Bore2.75 in (69.85 mm), bushing included (per IPD 2995204 equivalent)
Valve Pockets0 (flat/bowl crown, no valve reliefs)
Engine FamilyCaterpillar 3500 series diesel (3508 / 3512 / 3516 and B/C variants)
Compression Ratio14:1 (per Cat Parts Store listing description)

Technical notes

The 299-5204 is Caterpillar's 170 mm long-bore piston used across the 3500-series diesel engine family, including the 3512B marine application along with 3508/3508B, 3512/3512C and 3516/3516B. Distributor listings describe it as a piston body supplied with pin and pin clips; aftermarket one-piece-steel equivalents (IPD/Reliance) feature a closed oil-cooling gallery and a combustion bowl crown with no valve pockets. Pin bore is 2.75 in (69.85 mm) with a bushing. The part is offered standalone as a piston assembly and within full cylinder packs (piston with pin and locks, ring set, and liner with O-rings). All corroborating sources catalog it strictly under diesel 3500-series engines; it is not the spark-ignited G3500 gas-engine piston.

Compliance

Sold as a Caterpillar OEM-numbered engine spare and replicated by aftermarket suppliers (IPD/Reliance, KMP) under the same OEM reference; no marine class-society certification is asserted by the distributor listings reviewed.

Compatibility

Other parts in this series

Related

RFQ answered within ~4 h at major hubs routed to vetted suppliers no public pricing

Frequently asked questions

Does Caterpillar piston 299-5204 fit the 3512B marine engine?
Yes. Multiple independent diesel-parts distributors list 299-5204 (2995204) as fitting the Cat 3512B, alongside the 3508/3508B, 3512/3512C and 3516/3516B engines in the 3500 diesel series.
Is 299-5204 a complete cylinder kit or just the piston?
299-5204 itself is the piston assembly (piston body with pin and pin clips). It is also packaged into complete cylinder kits that add the piston rings and a liner with O-rings.
Will 299-5204 work on a G3508/G3512/G3516 gas engine?
No. Every corroborating source catalogs this piston under the 3500-series diesel engines only. The spark-ignited G3500 gas engines use different pistons, so 299-5204 should not be applied to gas variants.
Request quote