Kharkov Engine Design Bureau
PROSPECTS OF APPLICATION OF
TWO-STROKE TURBO-PISTON
OPPOSED-PISTON DIESEL ENGINE OF TD
FAMILY IN ARMORED VEHICLES
Kharkov engine design bureau
Main advantages of TD engines.
Engines of this family have following design characteristics, which ensure advantages
over rival firms, which manufacture four-stroke engines:
1. Small overall dimensions in combination with high power.
2. Small heat emission to the cooling system and possibility to operate at high temperatures
of liquid and motor oil cooling.
3. Small displacement and weight of power pack compartment of combat vehicle
4. High acceleration and brake power of the engine.
5. Good effectiveness.
6. Minor losses of engine power when
operating at high ambient temperatures
and in mountain.
7. High reliability and maintainability
8. Multi-fuel operation
9. Universal layout of engine
10. Reliable starting.
Kharkov engine design bureau
1. Small overall dimensions in combination with high power.
Engine 6TD-2 – one of the representatives of TD family – has displacement 0.88m3 and power
1200 hp, power-to-weight ratio makes 1363 hp/m3
One of the best rival firm has following performances:
Russian engine V92S2 has displacement 1.18m3 and develops power up to 1000 hp; power-to-
weight ratio makes 847 hp/m3, at that it should be taken into consideration that engine
V92S2 does not include starter-generator and high-pressure air compressor and engine
6TD-2 does have them.
German engine МV873KA501 of "МТU" company has displacement 3.68 m3 and develops
power up to 1500 hp; power-to-weight ratio makes 407 hp/m3.
As evident from the examples the power-to-weight ratio of engines of 6TD type is 1.6…3.3
times higher as compared to the competitors.
Smaller overall dimensions of 6TD engines determine smaller weight as compared to the other
engines. Specific weight of 6TD-2 engine makes 0.98 kg hp, that is better than Russian
engine V92S2 by 20% and than German engine МV873КА501– by 80%.
These high performances are achieved due to application of two-stroke cycle in diesel operation
and higher speed of crankshaft (2800 min-1). The letter gives possibility to transfer power
from engine to the gearboxes without intermediate reduction gear, which increases
weight, volume of engine compartment and power loss of power unit as a whole.
Kharkov engine design bureau
2. Small heat emission to the cooling system and possibility to operate at high
temperatures of liquid and motor oil cooling.
Total heat emission of two-stroke engine to the cooling liquid and oil makes 17…18% of
heat entered the engine together with fuel (1.6 MJ/kWh). In four-stroke engines this
figure makes 22…25% (2.1 MJ/kWh). Therefore if the power of engines is equal the
application of engines of 6TD type ensures decrease of the required power of cooling
system by more than 30% in comparison to the four-stroke ones that makes is possible to
decrease the size of radiators and power consumption for fan drive of this system.
In case of upgrading of the existing models of armored vehicles when installing new engine of
TD type having power by 30% higher than standard one the replacement of the existing
cooling system is not required as the total heat emission of the engine will be the same.
Engines of TD type can operate at 130qqC temperature of cooling liquid and oil. This gives the
advantage when operating in desert.
Kharkov engine design bureau
3. Small displacement and weight of power pack compartment of combat vehicle.
Power pack compartments occupy 30…40% of the total space of the armored vehicle.
Weight and size of the combat vehicle substantially depend on the size of power pack
compartment.
Internal space of tanks of Ukrainian manufacture does not exceed 11m3, and size of PPC does
not exceed 3.1m3 with engine power of 1200 hp (T-84 tank). The internal space of tanks of
European countries with four-stroke engine (France, England, Sweden, Germany) makes
17…18m3, and PPC size is 6…7m3. Note that engine occupies 30…35% and power unit
cooling system occupies 30…40% of the PPC. Basing on advantages in comparison to the
four-stroke engines namely smaller sizes of engine and cooling system PPC with engine of
TD type leaving its competitors behind was developed.
Power-to-weight ratio of new tanks of the developed countries makes: England – 240 hp/m3,
Russia - 312 hp/m3, Germany - 333 hp/m3, Ukraine - 400 hp/m3.
Basing on these figures the Ukrainian PPC is 1.2…1.6 times better than competitors' one.
Kharkov engine design bureau
4. High acceleration and brake power of the engine.
Engines of TD type are equipped with compressor of supercharging air and power turbine,
which have direct rigid (gear) connection with engine crankshaft.
This structure ensures high accelerating characteristics of combat vehicle.
When engine braking the tank produces brake power, which makes 50% of the rated effective
power. In four-stroke engines this figure makes not more than 20…25%. High
acceleration and brake power of the engine ensure advantages when operating the combat
vehicle.
Kharkov engine design bureau
5. Good effectiveness.
The indicated efficiency of TD-type engines is 50%, the effective efficiency is 40%, the fuel rate
is 155…165 g/hp.h, which corresponds to the best two-stroke and four-stroke diesel
engines. Taking into account that the power loss in the power pack compartment fitted
with the engines of TD type are less owing to non-availability of losses in the intermediate
reduction gear, decrease of power consumption for cooling system fan drive, the
operational effectiveness of these engines is better than of four-stroke engines.
Kharkov engine design bureau
6. Minor losses of engine power when operating at high ambient temperatures and in
mountain.
The power losses of engines of TD type are 1.8…2.2 times less than those of four-stroke engines
when operating at +55ºC. This advantage is achieved due to the high effectiveness of
turbo-supercharging aggregates, high level of air charge turbulization in the combustion
chamber, intensive system of carburation and combustion.
Kharkov engine design bureau
7. High reliability and maintainability
In the TD-type engines the gas exchange process is performed by way of direct-flow movement
of air and gas in the engine cylinder at the expense of pressure difference in the inlet and
outlet receivers. There is no gas-distributing valve gear typical for the four-stroke engines
in the TD-type engines. Besides, in TD type engine the combustion chamber is formed
directly between two moving pistons, this eliminates availability of the cylinder head and
the gas joint in this place. According to the statistical data 40…50% failures in the four-
stroke engine operation are caused by damages of gas-distributing valve gear and seal
failure of gas joint between the cylinder head and engine block.
The most frequent damages of valves and seal failure of gas joint happen at high ambient
temperature, it requires the additional routine maintenance and repair during four-stroke
diesel engine operation.
During operation of TD-type engines the fulfillment of above-mentioned scope of works is not
required.
Kharkov engine design bureau
8. Multi-fuel operation
The TD-type engines make it possible to use jet fuel (kerosene) and petrol along with diesel
fuel.
This requirement is met at the expense of availability of the heat plate in the pistons, which
reaches the temperature up to 1000ºC and ensuring the high effectiveness of the fuel
combustion with the nozzles arranged in the combustion chamber at the equal distances.
Because of the outlet valves in the four-stroke diesel engines the meeting of this requirement is
made with some restrictions.
Kharkov engine design bureau
9. Universal layout of engine
All versions of TD-type engines enable power take-off from two sides of crankshaft plus
additional power take-off for the cooling system fan drive or other needs. The overall
dimensions of engine are small: the height of engine is 580mm, the width is 950 mm,
which enables a big variety of versions of its installation into power pack compartments of
various armoured vehicles.
The engine includes the starter-generator of 5, 10, 18 kW and high-pressure compressor of
150atm, which are not available in a lot of four-stroke engines.
As a rule the engine is installed on three supports (two supports in the clips and one floating
support), it does not require the procedure of the common centering with the reduction
gear and gear boxes as it is required for four-stroke engines.
The TD-type engines can be connected with the power-consuming units through tooth-type
coupling, coupling with rubber-bushed studs, torus type coupling or using the
engagement. Engine can operate with cooling systems of ejector and fan types with
rarefaction at the suction up to 0.015МPа and counter-pressure at the outlet up to 0.034
МPа.
Kharkov engine design bureau
10. Reliable starting.
The engines are equipped with pneumatic, electric and combined starting systems.
Starting facilitation systems are available: autonomous torch heater and calorizer starting
system.
The engine is surely started over the temperature range from minus 400C to plus 550С.
It can be started using the tow and using the auxiliary power source (APU).
Kharkov engine design bureau
RELIABILITY AND LIFE OF TANK DIESEL ENGINES
CRITERIA COMPARATIVE TABLE
Volume mass coefficient
Country & Engine Power, Mass, Op. Volume
HP kg volume, l mass
coeff-t
Kvm
Ukraine 5TDFMA 1050 1050 13,6 77,2
Ukraine 6TD-2 1200 1180 16,3 72,4
Ukraine 6TD-3 1400 1210 16,3 74,2
Russia V-46-6 780 1020 38,2 26,7
Russia V-92C2 1000 1020 38,2 26,7
Poland V46-TK PZ Volya 1000 1020 38,2 28,5
Germany MB873 1500 1090 38,2 54,3
Germany MT883 1500 2590 47,7 65,7
Britain C12V 1200 Perkins 1200 1800 27,4 72
Israel AVDS 1790-9A 1200 1880 26,1 75,9
China X150-960 960 2223 29,3 47,2
Better 50…100 *
* Kosjak A.F., Bernadiner A.G., Cavushkin V.P.
Снижение металлоемкости дизелей. - Труды ЦНИИДИ, 1981, p.13-21
Kharkov engine design bureau
RELIABILITY AND LIFE OF TANK DIESEL ENGINES
CRITERIA COMPARATIVE TABLE
Average Piston Speed, Average effective pressure and Life criteria
Country & Engine Power, Rot. Size D/L, Op. Av. Av. Life
HP freq., mm volume, Piston effect- crite-
r/min l Speed tive pres- ria,
Vp, m/s sure Pe, x=Vp*
bar Pe
Ukraine 5TDFMA 1050 2850 120/ 2x120 13,6 11,4 12,2 139,1
Ukraine 6TD-2 1200 2600 120/ 2x120 16,3 10,4 12,7 132,1
Ukraine 6TD-3 1400 2850 120/ 2x120 16,3 11,4 13,6 155
Russia V-46-6 780 2000 150/180 38,2 12 9,2 110,4
Russia V-92C2 1000 2000 150/180 38,2 12 11,8 141,6
Poland V46-TK PZ Volya 1000 2000 150/180 38,2 12 11,8 141,6
Germany MB873 1500 2600 170/175 38,2 15,2 10,9 165,7
Germany MT883 1500 3000 144/140 47,7 14 16,4 229,6
Britain C12V 1200 Perkins 1200 2300 135/152 27,4 11,7 18 210,6
Israel AVDS 1790-9A 1200 2400 146/146 26,1 11,7 15,4 180,2
China X150-960 960 2200 150/160 29,3 11,7 11,6 135,7
Better <13 <14 <170
Kharkov engine design bureau
RELIABILITY AND LIFE OF TANK DIESEL ENGINES
CRITERIA COMPARATIVE TABLE
Heat emission, Volume and Mass of Power Pack
Country & Engine Tank Power, Rot. Size D/L, Op. Q, dQ PP PP Nv, d Mn, d
HP freq., mm volume, taus.kca Volume, mass, kg hp/kub. kg/hp
r/min l l/hr kub.m m
Ukraine 5TDFMA T-72 Upg 1050 2850 120/ 2x120 13,6 285 2% 3,0 2900 350 -10% 2,8 10%
Ukraine 6TD-2 Oplot 1200 2600 120/ 2x120 16,3 340 21% 3,1 3000 387 Base 2,5 Base
Ukraine 6TD-3 1400 2850 120/ 2x120 16,3 410 46% 3,2 3100 438 13% 2,2 -11%
Russia V-46-6 T-72 780 2000 150/180 38,2 280 Base 3,2 3200 244 -37% 4,1 64%
Russia V-92C2 T-90 1000 2000 150/180 38,2 365 30% 3,2 3300 313 -19% 3,3 32%
Poland V46-TK PZ Volya PT-91 1000 2000 150/180 38,2 420 50% 3,2 3400 313 -19% 3,4 36%
Germany MB873 Leopard-2 1500 2600 170/175 38,2 580 107% 7,2 6150 208 -46% 4,1 64%
Germany MT883 Leopard-2 1500 3000 144/140 47,7 520 86% 4,3 5440 349 -10% 3,6 45%
Britain C12V 1200 Perkins Challenger-2 1200 2300 135/152 27,4 445 59% 5,0 4400 240 -38% 3,7 47%
Israel AVDS 1790-9A Merkava-3 1200 2400 146/146 26,1 425 52% 7,5 6500 160 -59% 5,4 117%
China X150-960 Type 80 960 2200 150/160 29,3 350 25% 3,2 3300 300 -23% 3,4 38%
Kharkov engine design bureau
RELIABILITY AND LIFE OF LIGHT ARMOURED VEHICLES DIESEL ENGINES
CRITERIA COMPARATIVE TABLE
Country Engine type Power, Rotation Piston Piston Operatio Mass, Kvm, Av. Pe, Bar Life Veng, d Nv eng, Q, d Ne
HP Frequen Diam stoke, n kg kg/l Piston crite-ria, kub. Veng hp/kub. t.kkal/h cool
cy, r/min eter, mm volume, Speed x=Vp*Pe m m
mm liter Vp, m/s
Россия УТД-20 300 2600 150 150 15,9 665 41,8 13 6,5 84,9 0,73 Base 412,2 108,0 Base
Россия УТД-29 500 2600 150 150 26,5 850 32,1 13 6,5 84,9 0,77 6% 651,1 180,0 67%
США VTA-903Т 600 2600 140 121 14,8 1035 69,9 10,46 14,0 146,8 1,49 105% 401,4 213,3 98%
США 6V53T 264 2800 98,5 114,3 5,22 750 143,7 10,67 8,1 86,7 0,80 10% 329,0 93,9 -13%
ФРГ МВ-883-EaSa 600 2200 165 175 22,4 1250 55,8 12,8 11,0 140,3 1,41 94% 424,5 242,4 124%
Англия CV8TCA 550 2300 135 152 17,4 1292 74,3 11,65 12,4 144,1 1,71 135% 321,3 222,2 106%
Франция HS115-2 280 3000 110 108 8,2 625 76,2 10,8 10,2 110,6 0,81 11% 345,3 100,0 -7%
Украина 3ТД-2 400 2600 120 2x120 8,15 800 98,2 10,4 8,5 88,3 0,68 -6% 585,6 120,0 11%
Better 50…100 <13 <14 <120
Kharkov engine design bureau
UNIFICATION OF ENGINES AND PROSPECT OF FURTHER DEVELOPMENT.
Engines of TD series have the same standard size (cylinder diameter - 120mm, piston
stroke - 120 mm). Particular modifications are given below (The achieved level of power of each
modification is not limited and can be increased by 20% depending on the requirements):
Engine name Power, hp Rated speed, Qty of Purpose
min -1 cylinders
3TD-1 280 2800 3 BTR-70
BTR - 80
BMP- 1
3TD-2 400 2600 3
BMP- 2
BTR - 50
3TD-3 500 2600 3 BTR - 4
3TD-4 600 2600 3 BMP- 3
5TDF 700 2800 5 tank Т- 64
5TDFM 850 2800 5 Tank
BМ "Bulat"
Tank
5TDFMA 1050 2850 5
BМ "Bulat-2"
Т-72, Т-55
6TD-1 1000 2800 6 Tank Т-80UD
6TD-2 1200 2600 6 Tank Т-84,
"Oplot"
6TD-3 1400 2850 6
Kharkov engine design bureau
The comparative analysis demonstrates the superiority of tanks equipped with the
power pack compartment having two-stroke engines of TD family in available
power, which determines the weight and dimension characteristics of the
combat vehicle, mobility, dimension of silhouette to be hit.
CONCLUSION.
During development of the prospective models and upgrading
of the available armoured vehicles it is reasonable to use
two-stroke opposed-piston engines of TD-type as it ensures
the overwhelming advantages in comparison with
competitors
