Gravely 450
The Gravely 450 is a tractor produced by Gravely Lawn Tractors. It is equipped with a 816 cc 49.8 ci engine. The listed engine power is Gasoline (listed): 16.5 hp / 12.3 kW. Transmission: Swiftamatic 8. Operating weight: 950 lbs 430 kg.
Engine Power
Gasoline (listed): 16.5 hp / 12.3 kW
Fuel & Capacities
5.3 gal
20.1 L
Transmission
Swiftamatic 8
Operating Weight
950 lbs
430 kg
Overview
 | 1970
400 SeriesGarden tractor
400 Series
Garden tractor |
|---|
Production | |
|---|---|
Manufacturer | Gravely |
Garden tractor | |
Gravely 450 Engine | |
|---|---|
16.5HP Onan 816cc 2-cyl gasoline | |
Fuel tank | 5.3 gal
20.1 L |
Engine details ...  | |
Gravely 450 Transmission | |
|---|---|
4-speed gear | |
Transmission details ...  |
Mechanical | |
|---|---|
Two-wheel drive | |
Manual steering | |
Open operator station. |
Dimensions & Tires | |
|---|---|
Weight | 950 lbs
430 kg |
Front tire | 16x6.50-8 |
Rear tire | 23x8.50-12 |
Full dimensions and tires ...  | |
Electrical | |
|---|---|
Ground | negative |
Battery volts | 12 |
References | |
|---|---|
 | |
Service Manual 424, 430, 432, and 450 (14535P1) published in 1972 | |
Gravely '70 published in 1970 |
Engine
Engine Detail — 816 cc / 49.8 ci Gasoline
Manufacturer | Onan CCKA |
Fuel Type | Gasoline |
Configuration | 2-cylinder, air-cooled |
Displacement | 816 cc
49.8 ci |
Bore/Stroke | 3.00x3.25 inches
76 x 83 mm |
Power | 16.5 hp
12.3 kW |
Air cleaner | dry element |
Rated RPM | 3600 |
Starter volts | 12 |
Sparkplug gap | 0.025 inches
0.635 mm |
Intake valve clearance | 0.011 inches*Cold
0.279 mm |
Exhaust valve clearance | 0.011 inches*Cold
0.279 mm |
Oil capacity | 2 qts
1.9 L |
Transmission
Transmission — Swiftamatic 8
Transmission | Swiftamatic 8 |
Type | shaft-driven gear |
Gears | 4 forward and reverse |
Oil capacity | 5 qts
4.7 L |
Oil type | SAE 90W-EP |
Two-speed shift-on-the-move affects transmission and PTO speed. Additional two-speed range for transmission can be shifted only when stopped. Right-hand directional clutch lever controls forward and reverse. | |
Dimensions
Gravely 450 Tires | |
|---|---|
Lawn/turf front | 16x6.50-8 |
Lawn/turf rear | 23x8.50-12 |
Dimensions | |
|---|---|
Length | 75.5 inches
191 cm |
Width | 41.75 inches
106 cm |
Height | 43 inches
109 cm |
Shipping weight | 950 lbs
430 kg |
Attachments
Attachment overview | |
|---|---|
30" mid-mount mower deck | |
40" mid-mount mower deck | |
50" mid-mount mower deck | |
Garden tractors are capable of using tillers, plows, or other ground-engaging attachments. TractorData does not list details of these attachments. |
Photos
Gravely 450 in red paint, right side.
Gravely 450 in yellow paint, left side.
Recommended Implements & Sizing Guide
Engineering recommendations for Gravely Lawn Tractors Gravely 450 based on its 16.5 HP power envelope and ASAE agricultural standards.
| Implement & Operation | Recommended Size | Workload Rating | Engineering Notes |
|---|---|---|---|
Moldboard PlowPrimary Tillage | 1 to 2 Bottom (12")1 - 2 铧 (30 cm) | Light Duty | Ideal for garden plots and light sandy soil. |
Rotary Cutter / MowerMowing & Clearing | 4 ft (48 in)1.2 m | Light Duty | Pasture clipping and light brush under 1" diameter. |
Rotary TillerSeedbed Prep | 42 to 48 in105 - 120 cm | Light Duty | Covers compact tractor tire width. |
Sizing & Soil Condition NoteActual implement sizing varies depending on local soil conditions (heavy clay vs sandy loam), field slope, and operating speed. Heavy tillage implements may require front ballast weights and wheel weights.
Fluids, Capacities & Working Autonomy
Standard fluid requirements, service intervals, and continuous runtime estimates for Gravely Lawn Tractors Gravely 450.
Estimated Continuous Field Runtime: 6.2 hrs
Approximately 6.2 hours of continuous field operation at ~75% rated power on a full tank (5.3 gal / 20.1 L).
Estimated 75% Load Fuel Burn~0.9 gal/hr (3.2 L/hr)
Engine Crankcase Oil
SAE 15W-40 (Heavy Duty Diesel)
Standard Spec: API CK-4 / CJ-4 Heavy Duty
Service Interval: 150 – 250 Hours
Transmission & Hydraulic System
UTTO (Universal Tractor Transmission Oil)
Standard Spec: ISO VG 46 / 68 (Wet Brake & Trans Compatible)
Service Interval: 600 – 1000 Hours
Engine Cooling System
50/50 Ethylene Glycol Pre-mix
Standard Spec: ASTM D6210 / Heavy-Duty OAT Antifreeze
Service Interval: 2 Years / 1500 Hours
Gravely Lawn Tractors Gravely 450 Specification Unit Converter
Convert power, fluid capacities, and operating weights between metric and imperial standards for Gravely Lawn Tractors Gravely 450.
Converted Equivalents:
Horsepower (HP)16.5 hp
Kilowatts (kW)12.3 kW
Metric Horsepower (PS / CV)16.7 PS
Direct Competitor Comparison
Compare Gravely 450 against same-era industry alternatives in the same horsepower class.
Current Model
Gravely Lawn Tractors
Gravely 450
Engine Power:Gasoline (listed): 16.5 hp / 12.3 kW
★ Baseline Reference
International HarvesterMarket Competitor
International Harvester D-215
Engine Power:15
Production Years:1962 - 1964
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