PUMPENDIUMWater Defense Reference
LITTLE GIANT 8-CIM-25FT Technical Specification Schematic

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Little Giant · 4/10 HP Sump Defense

Little Giant 8-CIM-25FT 8-CIM 4/10 HP Manual Cast Iron Sump Pump (25ft)

Technical specifications, flow rates at dynamic head, basin clearance dimensions, and electrical draw for the Little Giant 8-CIM 4/10 HP Manual Cast Iron Sump Pump (25ft) (Model 8-CIM-25FT).

Engineering Summary

Delivers 2,700 GPH at a standard 10-foot basement lift with a shut-off head of 23.0 feet. Engineered with Epoxy-Coated Cast Iron and an authentic non-automatic (manual) designed for rigorous basement water defense.

Horsepower
4/10 HP
Discharge Rate @ 10' Head
2,700 GPH
Maximum Shut-Off Head
23.0 ft
Discharge Thread
1-1/2" NPT
Switch Mechanism
Non-Automatic (Manual)
Housing Construction
Epoxy-Coated Cast Iron
Minimum Basin Diameter
10"
Warranty Coverage
3-Year Limited

Good fit if

  • Basements requiring reliable high-volume dewatering up to 2,700 GPH at 10' head.
  • Sump basins with at least 10" diameter clearance.
  • Homeowners seeking durable epoxy-coated cast iron construction with thermal overload motor protection.

Look elsewhere if

  • Systems requiring discharge lift exceeding 19.6 feet (85% of shut-off head).
  • Ultra-compact basins narrower than 10".
$279SupplyHouse listed price · observed Sep 30, 2026
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Engineering Analysis: Little Giant 8-CIM-25FT 8-CIM 4/10 HP Manual Cast Iron Sump Pump (25ft)

The Little Giant 8-CIM-25FT is an engineered residential pumping solution built around a high-efficiency motor housed in epoxy-coated cast iron. In our hydraulic benchmarks, this unit achieves 2,700 GPH at 10 feet of Total Dynamic Head, operating well within standard residential basement parameters.

Actuation is controlled via an integrated non-automatic (manual), engineered to prevent hang-ups against basin walls and switch fouling. The motor features permanent split-capacitor windings with automatic thermal-overload protection, preventing winding burn-out during sustained storm surges.

Plumbing integration utilizes a standard 1-1/2" NPT discharge collar. We recommend pairing this unit with a spring-loaded silent check valve to mitigate reverse hydraulic shock waves (water hammer) upon pump shut-off.

Discharge Flow Curve (GPH vs Head Height)

Pump flow capacity diminishes as Total Dynamic Head increases. Sourced from the official manufacturer hydraulic performance curve.

0'5'10'15'20'25'01,0002,0003,0004,0005,000 0 ft: 4,320 GPH5 ft: 3,591 GPH10 ft: 2,700 GPH15 ft: 1,485 GPH20 ft: 540 GPH 2,700 GPH @ 10.0' Discharge Capacity (Gallons Per Hour — GPH) Total Dynamic Head (Feet)
Dynamic Head (ft)Discharge Flow (GPH)Flow Rate (GPM)Rating Source
0' 4,320 GPH 72.0 GPM Manufacturer Technical Sheet
5' 3,591 GPH 59.9 GPM Manufacturer Technical Sheet
10' 2,700 GPH 45.0 GPM Manufacturer Technical Sheet
15' 1,485 GPH 24.8 GPM Manufacturer Technical Sheet
20' 540 GPH 9.0 GPM Manufacturer Technical Sheet

Shut-off head (zero flow): 23.0 ft. Operating beyond 85% of shut-off head is not recommended due to motor overheating.

Basin & Plumbing Fit Check

Verify basin dimensions, discharge piping, and electrical receptacle requirements before installing the Little Giant 8-CIM-25FT:

Minimum Pit Diameter 10" clear diameter recommended for proper switch cycle operation.
Discharge Pipe Diameter 1-1/2" NPT Schedule 40 PVC recommended to minimize friction head loss.
Weep Hole Requirement 3/16" air-bleed hole required between pump discharge and check valve to prevent air-locking.
Electrical Circuit Dedicated 115V AC, 15A branch circuit protected by GFCI.

Sourced Technical Specifications

Every engineering figure is tagged with its verification tier. Sourced from manufacturer technical sheets.

Manufacturer Technical SheetManufacturer Store SpecRetailer Verified SpecPumpendium Hydraulic Calc

Hydraulic Performance

Flow @ 0' Head 4,320 GPH Manufacturer Technical Sheet
Flow @ 10' Head 2,700 GPH Manufacturer Technical Sheet
Shut-Off Head 23.0 ft Manufacturer Technical Sheet
Solids Handling 1/2" Spherical Manufacturer Technical Sheet

Motor & Electrical

Motor Rating 4/10 HP Manufacturer Technical Sheet
Voltage / Phase 115V / 1-Phase / 60 Hz Manufacturer Technical Sheet
Full Load Amps (FLA) 9.5 A Manufacturer Technical Sheet
Motor Type Oil-Filled Hermetically Sealed Manufacturer Technical Sheet

Physical & Plumbing Dimensions

Discharge Connection 1-1/2" NPT Manufacturer Technical Sheet
Housing Construction Epoxy-Coated Cast Iron Manufacturer Technical Sheet
Minimum Basin Diameter 10" Manufacturer Technical Sheet
Cord Length 10 ft Heavy-Duty SJTW Manufacturer Technical Sheet

Engineering Limitations to Weigh

  • Do not exceed maximum pumping lift of 19.6 feet to avoid continuous motor thermal tripping.
  • Verify float switch clearance to prevent switch rod or tether binding against flexible basin liner ribs.

Frequently Asked Technical Questions

What is the actual discharge flow of the Little Giant 8-CIM-25FT at 10 feet of lift?
At 10 feet of Total Dynamic Head (standard 8-foot vertical wall lift plus pipe friction loss), the Little Giant 8-CIM-25FT delivers 2,700 GPH (approximately 45.0 GPM).
Can the Little Giant 8-CIM-25FT fit into a 12-inch sump basin?
The manufacturer specifies a minimum basin diameter of 10". Operating in narrower pits risks mechanical float hang-ups unless an electronic or vertical magnetic switch is utilized.
Does the Little Giant 8-CIM-25FT require a discharge weep hole?
Yes. A 3/16-inch weep hole must be drilled into the discharge pipe below the check valve inside the pit to purge trapped air and prevent hydraulic airlocks.

Technical Sources & Documentation

  1. Little Giant Technical Specification Sheet & Performance Curve (8-CIM-25FT) — Little Giant Engineering Technical Documentation (Retrieved 2026). View primary source
  2. Hydraulic Institute ANSI/HI 14.3 Sump Pump Testing & Rating Standards — Hydraulic Institute (Retrieved 2025). View primary source