David Brown 3800 Selectamatic

The David Brown 3800 Selectamatic is a tractor produced by David Brown. It is equipped with a 146.1 ci 2.4 L engine. The listed engine power is 39.16 hp 29.2 kW. Transmission: 12 forward and 4 reverse. Operating weight: 3885 lbs 1762 kg.

Engine Power

39.16 hp 29.2 kW

Fuel & Capacities

9.5 gal 36.0 L

Transmission

12 forward and 4 reverse

Operating Weight

3885 lbs 1762 kg

Overview

	1968 - 1971 Utility tractor

Production
Manufacturer	David Brown
Utility tractor
Built in Meltham Mills, Huddersfield, England
Original price	$4,000 (1971)

David Brown 3800 Engine
David Brown 2.4L 3-cyl gasoline
Engine details ...

David Brown 3800 Power
PTO (claimed)	39 hp 29.1 kW
Drawbar (tested)	32.13 hp 24.0 kW
PTO (tested)	39.16 hp 29.2 kW
Performance test details ...

Mechanical
Two-wheel drive
Final drives	spur gear
Differential lock	rear diff lock standard
Steering	manual
	power-assist optional
Mechanical shoe brakes
Open operating station.

Capacity
Fuel	9.5 gal 36.0 L
Hydraulic system	6 gal 22.7 L

Hydraulics
Type	Selectamatic
Capacity	6 gal 22.7 L
Pressure	2000 psi 137.9 bar
Pump flow	7.3 gpm 27.6 lpm

Tractor hitch
Rear Type	I
Control	position and draft control
Rear lift (at ends)	1600 lbs (working) 725 kg
	1950 lbs (static) 884 kg

Power Take-off (PTO)
Rear PTO	live
Rear PTO Type	540/1000

Dimensions & Tires
Wheelbase	76 inches 193 cm
Weight	3885 lbs 1762 kg
Front tire	6.00-16
Rear tire	13.6/12-28
Full dimensions and tires ...

Engine

Engine Detail — 146.1 ci / 2.4 L Gasoline

Manufacturer	David Brown
Fuel Type	Gasoline
Configuration	3-cylinder, liquid-cooled
Displacement	146.1 ci 2.4 L
Bore/Stroke	3.939x4.000 inches 100 x 102 mm
Air cleaner	oil bath
Compression	6.75:1
Rated RPM	2200
Operating RPM	700-2200
Torque	115 lb-ft 155.9 Nm
Torque RPM	1400
Starter volts	12
Oil capacity	6.75 qts 6.4 L
Coolant capacity	9 qts 8.5 L

Transmission

Transmission options
6-speed gear
12-speed gear

Transmission — 6 forward and 2 reverse gear

Type	gear
Gears	6 forward and 2 reverse
Clutch	dry disc
Oil capacity	24 qts 22.7 L

Transmission — 12 forward and 4 reverse gear

Type	gear
Gears	12 forward and 4 reverse
Clutch	dry disc
Oil capacity	24 qts 22.7 L

Dimensions

David Brown 3800 Tires
Ag front	6.00-16
Ag rear	13.6/12-28
Ag front	14.9/13-24
	14.9/13-28

Dimensions
Wheelbase	76 inches 193 cm
Length	115.625 inches 293 cm
Width	64.5 inches (min) 163 cm
Height (hood)	51.25 inches 130 cm
Operating weight	3885 lbs 1762 kg
Ballasted weight	5835 lbs 2646 kg
Clearance (front axle)	17.5 inches 44 cm
Clearance (drawbar)	11.75 inches 29 cm
Front tread	48 to 72 inches 121 to 182 cm
Rear tread	48 to 76 inches 121 to 193 cm
Rear tread	60 to 80 inches 152 to 203 cm (PAVT)

Tests

Nebraska Tractor Test 1018
Gasoline 6-speed 2WD September 2 - 11, 1969 Link: Nebraska Tractor Test 1018 file
PTO performance
Power at rated engine speed	39.16 hp 29.2 kW
Fuel use	3.6 gal/hour 13.6 l/hour
Power at rated PTO speed	37.24 hp 27.8 kW
Fuel use	3.3 gal/hour 12.5 l/hour
Drawbar performance
Max power	32.13 hp 24.0 kW
Fuel use	3.4 gal/hour 12.9 l/hour
Gear 3 used for power test.
Max pull	4419 lbs 2004 kg
Gear 1 used for pull test.

Photos

David Brown 3800 Selectamatic tractor photo

Recommended Implements & Sizing Guide

Engineering recommendations for David Brown 3800 Selectamatic based on its 39.16 HP power envelope and ASAE agricultural standards.

Implement & Operation	Recommended Size	Workload Rating	Engineering Notes
Moldboard PlowPrimary Tillage	2 to 3 Bottom (14-16")2 - 3 铧 (35-40 cm)	Medium Duty	Standard utility farm tillage.
Rotary Cutter / MowerMowing & Clearing	5 ft (60 in)1.5 m	Medium Duty	Pasture maintenance and weeds up to 1.5" diameter.
Rotary TillerSeedbed Prep	54 to 60 in135 - 150 cm	Medium Duty	Thorough seedbed preparation in orchards and vegetable plots.
Disc HarrowSecondary Tillage	5 to 6 ft (16-18" discs)1.5 - 1.8 m (40-45 cm 耙片)	Light Duty	Small acreage soil break-up and secondary aeration.
Hay BalerHay & Forage	Small Square Baler (14x18")小方捆打捆机 (36x46 cm)	Medium Duty	Classic 2-string baler for horse and small livestock hay.

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 David Brown 3800 Selectamatic.

Estimated Continuous Field Runtime: 4.7 hrs

Approximately 4.7 hours of continuous field operation at ~75% rated power on a full tank (9.5 gal / 36 L).

Estimated 75% Load Fuel Burn~2 gal/hr (7.7 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