Engines and Components› Pistons and Piston Rings

Mini Spares

998cc Flat Top Piston

$35.44

SKU: P20950-20

In Stock
In Stock
Ships by Sep 12
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Mini Spares piston is a single 998cc flat top piston designed with high silicon content. It features drilled oil drain-back holes for maximum strength and is suitable for both road and race engines. This piston replaces original Hepolite pistons 18516KR and P20950 for the 998cc Coopers.
Show original supplier description
The Mini Spares Evolution design piston is a high-performance component manufactured from superior aluminum, intended for 998cc engines. These flat-top, non-slipper pistons are constructed with a high silicon content and feature drilled oil drain-back holes for enhanced strength, replacing older Hepolite designs. Suitable for compression ratios up to 12.5:1, this piston will yield approximately 9.6:1 CR when paired with a Cooper cylinder head. It is designed as a direct replacement for original Hepolite pistons 18516KR and P20950, used on the original 998cc Coopers. Note that these pistons are not dimensionally interchangeable with Hepolite types and must be installed in complete sets of four. For installation with later press-fit type connecting rods, the circlips can be discarded. The recommended usage is one piston per Mini. These pistons are also suitable for use with specialized heat treatments, making them a competitive option for any engine build.

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

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Specifications

BrandMini Spares
Part NumberP20950-20
CategoryEngines and Components

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Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

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