Journal of the Department of Agriculture, Journal of the Department of Agriculture, Western Australia, Series 4 Western Australia, Series 4
Volume 2
Number 2 February, 1961 Article 8
1-1-1961
Australian tractor tests : report on test no. 32 Australian tractor tests : report on test no. 32
G H. Vasey W. F. Baillie
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Recommended Citation Recommended Citation
Vasey, G H. and Baillie, W. F. (1961) "Australian tractor tests : report on test no. 32," Journal of the Department of Agriculture, Western Australia, Series 4: Vol. 2: No. 2, Article 8.
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AUSTRALIAN TRACTOR TESTS
•
•
REPORT ON TEST No. 32 (Farmers' Edition)
FORDSON DEXTA
(Tested for Ford Motor Co. of Australia Pty. Ltd., Geelong. Victoria)
,
.^^MMHS ^ K
A Fordson Dexta at Albany
T
HIS Report is t a k e n from t h e full Technical Report No. 32 of this t e s t : test results are shown here in briefer f o r m : fuller explanations are added. Values quoted may be rounded out to two i n s t e a d of t h r e e significant figures: to t h i s extent t h e values m a y differ slightly but not significantly from those shown in t h e Technical Report.G r a p h s of belt test performance, shown in t h e Technical Report, a r e not shown here.
T h e Technical Report is n o t available in large numbers, but it may be seen at, a n d copies of t h i s farmers' report m a y be h a d from, t h e offices of t h e State D e p a r t m e n t s of Agriculture, t h e Bureau of Sugar Experiment Stations (Queensland), and t h e Com- monwealth D e p a r t m e n t of P r i m a r y Industry.
1.—THE TESTS
(1) After twelve h o u r s of r u n n i n g - i n , two types of tests were carried out, in order to measure the performance of the engine, a s measured by t h e power in the belt driven by t h e belt pulley, a n d the performance of the tractor as a whole, as measured by
drawbar pull, t r a c t o r speed, wheel slip, a n d d r a w b a r horse-power (d.b.h.p.), with t h e t r a c t o r r u n n i n g on a b i t u m e n test track.
The m a i n results of these tests a r e given in Sections 2, 3, a n d 4. Other m e a s u r e - ments a n d observations were m a d e of
various features of the t r a c t o r ; these are given in Section 5.
In this Test No. 32. for the first time, tests were Included on the engine removed from the tractor. All normal auxiliaries were fitted and functioning; power output (shaft horse-power, s.h.p.) was measured at the crankshaft. See Section 2.
(2) Fuel Settings.—The engine of this t r a c t o r h a s only one fuel setting, a t which all t h e tests were carried out.
(3) Governor Control.—The engine was under t h e control of t h e governor set to give full fuel delivery, a n d so full power a t r a t e d engine speed.
The Australian Tractor Testing Committee is a joint body established by agreement between the Commonwealth, the States, and the University of Melbourne: under this agreement, the tests are carried out by the University of Melbourne. The address of the Tractor Testing Committee is:
C/o Department of Primary Industry, 301 Flinders Lane, Melbourne.
Journal of Agriculture, Vol 2 No 2, 1961
(4) Fuel.—Distillate, Diesel I n d e x 54, Specific Gravity 0.84; weight p e r Imperial gallon 8.41 lb.
(5) Specification.—Engine No. 1416077.
F o r a brief specification of t h i s t r a c t o r see Section 6 a t t h e e n d of t h i s report.
2.—SUMMARY OF POWER OUTPUT Table A
A t the Belt
At the Drawbar
(c) Fuel consumption in gallons/hour may be a simple unit, but it has no meaning unless we also quote the corresponding h.p. output.
(d) This is the " specific fuel consumption," the weight of fuel consumed per unit of energy developed by the engine ; (the unit of energy here is the h.p.-hour, similar to the electrical '• unit," the kilowatt-hour). When this figure is least the engine is giving its best economy or efficiency. I t is easy to change from column (e) to column (d) in Table B, e.g., as follows :—
1-75 galls./hr. while developing 30-0 h.p. means 1-75 — 30-0 galls./b.h.p./hr. = 0-058 gall./b.h.p./hr.
0-058 gall./b.h.p./hr. x 8-41 lb./gallon for this fuel = 0-49 lb./b.h.p./hr., as shown in column (d).
(e) Line 7, Table B., represents the average performance one might expect from the engine while driving a variety of belt
k loads, from light to heavy. In terms of average fuel consump- tion, it means about I f gallons an hour.
R a t e d engine s p e e d , r . p . m . M a x i m u m p o w e r (a) R a t e d p o w e r (6)
2,000 2 6 - 9 20(&2) M a x i m u m s h a f t h o r s e - p o w e r a t 2 , 0 0 0 r . p . m . : 3 3 * 0 . Note.—Letters in b r a c k e t s refer t o e x p l a n a t o r y foot- n o t e s .
(a) No atmospheric corrections are applied to diesel engines because there is no suitable formula ; the values shown above are, therefore, the observed maximum powers.
(6) Engines are not expected to run indefinitely at full or maximum power output. But they can be expected to run continuously for some hours at rated output, which is less than maximum, defined as follows :—
(61) Bated b.h.p. is defined as 85 per cent, of corrected maximum b.h.p. ;
(62) Bated d.b.h.p. is defined as 75 per cent, of corrected maximum d.b.h.p.
3.—BELT TESTS
T h e belt tests show t h e power (belt horse-power, b.h.p.) t h a t t h e t r a c t o r m a y be expected t o deliver w h e n driving a m a c h i n e by t h e belt.
Table B—Belt Test Results
I.- Rated engine speed, 2,000 r.p.m.
2. Fast idling speed 2,200 r.p.m.
3. Observed maximum b.h.p. a t rated speed 4. Corrected maximum
b.h.p. rated speed (a) 5. Calculated rated load (61) 6. Test at approximately
rated load
7. .Average loading under governor (e)
8. Measured engine torque at full fuel delivery
9. Repeat of (3) above after 67 hours
B.H.P.
3 0 0
3 0 0 25J
En- gine Speed
2,000
Fuel
Gall./ l b . / hr. (c) i b.h.p.
hr. (d)
1 • 75 0-49 Xo correction made
for diesel engines
25-9 2,125
1 7 1 2,140 1-6
1-2 0-51
0-61 87 ft. lb. a t maximum power
and rated speed
95 ft. lb. (maximum) a t 1,300 r.p.m.
Xo change
4.—DRAWBAR TESTS
(1) T h e following Tables C, D, a n d E, show t h e drawbar performance of t h e tractor, on t h e bitumen test t r a c k , wearing r e a r tyres 11 x 28, carrying m a x i m u m weight (1,500 lb. front 3,310 lb. r e a r ; total, 4,810 lb.), working in t h e gears named in t h e tables. Height of d r a w b a r 16 inches.
Drawbar tests, using s t a n d a r d weight of tractor (3,370 lb.), were carried out, b u t are not reported here.
Table C—Maximum Power, Rated ( 2 n d ) Gear
1. Rated engine speed, 2,000 r.p.m.
2. Observed maximum d.b.h.p. at rated en- gine speed ....
3. Corrected maximum d.b.h.p. at rated en- gine speed (a) 4. Calculated rated load (62)
D B H P
(/)
26-9
26-9 20
Pull lb.
2,850 Speed m.p.h.
3-54 Wheel
Slip
%
(?)
9 No correction made
for diesel engines
Table D—Pull a t Maximum d.b.h.p.
All gears, rated engine speed. See note (h).
Gear
1 2 3 4 5 6
D.B.H.P.
16 ( 0 27 28 28 28
Road
Pull lb.
3.700 2,850 2,200 1,725 1,000 gear not te
Speed m.p.h.
1-6 3-5 4-7 6 0 10-4 sted
Wheel Slip
Ze-
i s 9
« .->
3
(/) D.B.H.P. is the product of pull (lb.) and speed (m.p.h.) divided by 375.
(g) Wheel slip can be measured bo noting that, in travelling a given distance, the back wheels make more turns when working under load than when running with no load on the
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drawbar. The difference in these revolution counts divided by the former count gives the slip as a ratio, which can be written as a percentage (quoted in these tables to the nearest whole number.)
(A) These are not the maximum pulls available in the gears (i.e., not the maximum sustained pulls), but the pulls at maxi- mum, d.b. power, i.e., at full-throttle at rated engine speed.
(*) Engine not fully loaded, maximum d.b.h.p. in first gear limited by wheel slip.
Table E—Fuel Consumption. Various Loads, Rated (2nd) Gear
(4) Tractor Weights (lb.).
P u l l l b .
Speed m . p . h . D B H P
P e r - c e n t a g e
of M a x i -
m u m d . b . h . p .
Slip
F u e l
G a l l . / h r .
1,150 1,500 1,950 2,400
4 1 4-0 3-9 3-8
13 16 20f 24
47 60 75f 91
3 5 6 7
1-1 1-2 1-4 1-6
l b . / d . b . h . p .
h r .
0 - 7 3 0 - 6 5 0 - 5 9 0 - 5 5 t Rated drawbar load.
(2) Interpretation of Drawbar Tests.
(i) Drawbar tests a r e carried out on a h a r d prepared surface. Most field con- ditions present higher resistance to t h e tractor's motion, so t h a t , in t h e field, t h e maximum drawbar pulls available in any gear will usually be less t h a n those shown in the tables.
(ii) Wheel slip may also be greater in t h e field; to t h a t extent t r a c t o r speeds in miles per hour in t h e field will be less t h a n those shown in t h e tables.
(iii) Because of (i) a n d (ii) above, t h e drawbar horse-powers available in any gear in t h e field will usually be less t h a n those shown in t h e tables.
5.—OTHER OBSERVATIONS (1) Duration of Test.—67 hours, includ- ing r u n n i n g in.
(2) Repairs and Adjustments.—None.
(3) Engine—
Fuel settings—one, fuel p u m p calibra- tion checked in accordance with specification.
Heat controls—radiator and four-blade fan, t h e r m o s t a t .
Radiator water used—none.
Lubricating oil—S.A.E. 20.
Weight to engine, 14.0 lb.;
Weight from engine after test, 13.0 lb.
Weight condition
•Standard, unballasted tMaximum weight, heaviest
recommended Includes—
Water ballast (lb./wheel) ....
Solid ballast (lb./wheel) ....
Front
1,340 1,500
75
Rear ' Total
I
2,030 3,310 240 400
3,370 4,810 240 475
* This weight, including driver and fuel, was used in finding centre of gravity.
Special Note on Light-weight Tractors.—Tliis tractor is of the light-weight type designed for the operation of implements that are mounted on the three-point linkage, and controlled through the hydraulic system in such a way that some or all of the weight of the attached implement can be carried by the tractor, while the implement is at work. In this instance this is achieved by the Fordson Dexta " Qualitrol" unit.
A static test on the tractor in if« standard, or light-weight, condition showed that the hydraulic system was capable of increasing the tractor weight to not less than the maximum test weight without lifting the front wheels off the ground and without overloading the rear tyres.
•f Weight of tractor in drawbar tests quoted in this report.
(5) Wheels and Tyres.
T v r e s F r o n t H e a r
T y p e Size P r e s s u r e
O p e n c e n t r e bar t r e a d
11 x 2 8 , 6-ply 12 psi.
(6) Steering.—With track widths, front 53", rear 53", wheel base 72":—
Turning circles: Without brakes, L.H.
and R.H. 21'; with brakes, L.H. and R.H.
17'.
Comment: Easy to steer under load, sensitive to steering wheel; no power assistance.
(7) Centre of Gravity, with t r a c t o r in s t a n d a r d weight—2J" below, 29" forward of rear axle.
(8) Driver's Accommodation.—Access to seat, from either side forward of rear wheels. Foot-room and support, flat foot plates, foot rests, adequate. Comfort, deep plough-type seat with rubber cushion, ad- justable fore and aft 2Y'. Accessibility to controls, clutch a n d brake pedals 20" apart, pedals approximately 14" below loaded seat. Clearance between clutch pedal a n d steering wheel makes operation of clutch awkward when employing t h e live-drive clutch.
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Noise, sound p r e s s u r e level m e a s u r e d 3 feet above loaded seat, i n open field—
a t full power r a t e d speed—111 units, a t h i g h idling speed—105 u n i t s .
The special unit Is decibels of pressure compared with a base level of virtual silence. The levels quoted above are typical of tractors, which generally are noisy by accepted industrial standards.
(9) Instruments.—All clearly visible, m a r k i n g s a d e q u a t e . I n d i c a t i o n s were con- sistent t h r o u g h o u t tests. E n g i n e t a c h o - meter is m a r k e d for s t a n d a r d p.t.o. a n d belt speed a n d for road speed in t h e gears.
(10) Inspection of Engine and Trans- mission after Test.—After testing, t h e t r a c t o r was p a r t l y d i s m a n t l e d a n d i n - spected a n d found to be in a satisfactory condition.
(11) Instruction Books.—Instructions for s t a r t i n g , r u n n i n g , a n d m a i n t e n a n c e were satisfactory, a n d well illustrated.
6.—BRIEF SPECIFICATIONS
Fordson Dexta. (Based on Information Supplied by Manufacturers)
(1) Engine—No. 1416077.
4-stroke; 3 cylinders, vertical; c r a n k - shaft along t r a c t o r ; diesel ( i n - direct i n j e c t i o n ) .
Bore, 3 i " ; stroke, 5"; compression r a t i o , 16.5 : 1.
Rated speeds: Belt a n d d r a w b a r work, 2,000 r.p.m.
Fuel t y p e : Distillate.
Fuel system: Simms 3-cyl. in-line p u m p , 2-hole spray type injectors.
Two r e p l a c e a b l e - e l e m e n t filters in series. T a n k capacity, 7 gallons.
Air Cleaner: Oil b a t h .
Governor: P n e u m a t i c , incorporated in fuel p u m p .
Electrical system: 12-volt b a t t e r y a n d generator.
S t a r t i n g : Electric, h e a t e r in manifold a n d fuel p r i m e r for cold s t a r t i n g . Cooling: W a t e r (pressure s y s t e m ) , fan,
p u m p , a n d t h e r m o s t a t .
E x h a u s t : Vertical, a h e a d of operator.
Fordson Dexta s t a n d a r d s p a r k a r r e s t e r fitted which conforms w i t h S.A.E.
Code. See A u s t r a l i a n S p a r k Arrester. T e s t No. SPA-7.
Lubrication: Oil p u m p a n d full-flow filter, replaceable e l e m e n t type.
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(2) Chassis—
4-wheel; p n e u m a t i c tyres.
Wheel base 72".
Track w i d t h s : F r o n t 48" x 4" steps to 76", rear 48" x 4" steps to 76".
Tyre sizes: Front 5.50 x 16; r e a r 11 x 28.
Steering: Two-start worm drive.
Weight: Maximum, 4,810 lb.
(3) Belt Pulley—
Rear working, direction of r o t a t i o n a s required.
Diameter 9"; face w i d t h 6£".
Speed (at rated engine speed), 1,290 r.p.m.
Belt speed (at r a t e d engine s p e e d ) , 3,040 ft./min., in accordance w i t h overseas s t a n d a r d s (namely, 3,100
± 100 f.p.m.).
(4) Power Take-Off—
Centre r e a r ; clockwise; guarded.
Speed: 690 r.p.m. a t r a t e d engine speed, not in accordance w i t h overseas s t a n d a r d s (namely, 536 ± 10 r.p.m.). At engine speed of 1,550 r.p.m., p.t.o. would be 536 r.p.m.
Dimensions: 6 spline, 1 | " d i a m e t e r . (5) Drawbar—Linkage m o u n t e d d r a w b a r .
Height adjustable, 15"-26".
(6) Transmission—Conventional gears.
Clutch: Double dry p l a t e , 9" d i a m e t e r ; second throw of pedal o p e r a t e s live drive.
Gear ratios a n d road speeds (assuming no wheel slip) on 11 x 28 tyres, a t rated engine speed, as a d v e r - tised.
Forward Reverse
fieur ....
Ratio Speed.
m.p.h.
1 152-2
1-8 2 7 1 1
3-8 3 54 6
.-,()
4 43-5
8-3 5 26-5 10-7
6 15-5 17-5
L 98-4
2-8 H 35-2
7-7
(7) Hydraulics—Built-in, gear p u m p i n rear tranmission housing. Live drive.
(8) Three-point Linkage—Generally c o n - forms to BS1841-1951, Category 1.
O. H. VASEY, Officer In Charge Tractor Testing.
W. P. BAILLIE, Tractor Testing Officer.
September 1959. University of Melbourne.
