VR6 Glock
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сорри, украл на вортексе, так что все по-английски.
The following is a copy of the original VR6 tech manual, with notes where applicable.
Service Training
Self-Study Program 402
Volkswagen of America, Inc.
Sevice Training
Printed in U.S.A.
Printed 12/91
Part # WSP 521-402-00
All rights reserved. All information contained
in this manual is based on the latest product
information available at the time of printing.
The right is reserved to make changes at any
time without notice.
Always check Technical Bulletins and the mirofiche
system for information that may supersede any
information included in this manual.
*** Introduction ***
Volkswagen has developed a new six-cylinder engine called the VR-6.
This 2.8-liter engine is unique in that the V-angle between cylinder
banks is 15° rather than the 60° or 90° found in most conventional
V-6 engine designs.
The engine features a cast-iron crankcase, one light alloy crossflow
cylinder head with two valves per cylinder operated by chain-driven
overhead camshafts.
All fuel and ignition requirements of the VR-6 engine are controlled
by the Bosch Motronic M2.9 Engine Management System.
This Engine Management System features an air mass sensor, dual knock
sensors for cylinder-selective ignition knock regulation, and Lambda
regulation.
Exhaust gases are channeled through a 3-way catalytic converter.
*** Engine Specifications ***
Engine code: AAA
Design: Four-stroke, internal combustion engine in "Vee"/in-line
Displacement: 2.8 liter
Bore diameter: 81.0 mm
Stroke: 90.0 mm
**note this is listed as 90.3mm elsewhere
"Vee" angle: 15°
Compression ratio: 10:1
Fuel and ignition systems: Bosch Motronic M2.9
Emission control: Lambda control with catalytic converter
The name, VR-6 come from a combination of Vee and the German word
Reihenmotor. The combination of the two can be roughly translated
as "in-line Vee."
Volkswagen has designed the 15° VR-6 to take advantage of
conventional in-line six-cylinder engine features (single cylinder
head, narrow width and excellent balancing) with the advantages
of a V-6 engine design (short overall length and compactness).
*** VR-6 ***
The VR-6 was specifically designed for transverse installation
in front-wheel-drive vehicles. By using the narrow 15° VR-6 engine,
it was possible to install a six-cylinder engine in existing
Volkswagen models.
*** V-6 Conventional Design ***
A wider V-6 engine of conventional design would have required
lengthening existing vehicles to provide enough crumple zone
between the front of the vehicle and the engine, and between
the engine and the passenger cell.
Using the narrow VR-6 engine will help Volkswagen meet current
and future front-end crash standards.
*** Overview ***
The drop-forged steel, six-throw crankshaft runs in seven main
bearings. The connecting rod journals are offset 22° to one
another.
Overhead camshafts (one for each bank of cylinders) operate the
hydraulic valve lifters which, in turn, open and close the 39.0-mm
intake valves and 34.3-mm exhaust valves.
Because of the special VR-6 cylinder arrangement with two rows
of combustion chambers in the same cylinder head, the intake
runners between the two cylinder banks are of varying lengths.
The difference in intake length is compensated in the overhead
intake manifold. Each runner is 420 mm long.
Exhaust gases are channeled from two 3-branch cat-iron exhaust
manifolds into a sheathed Y-pipe. From there, they are channeled
into a single flow before passing over the heated Oxygen Sensor
and then to the catalytic converter.
The oil pump driveshaft is driven by the intermediate shaft.
Fuel injectors of the Bosch M2.9 Engine Management System are
mounted behind the bend of the intake manifolds. Besides being
the optimum location for fuel injection, this location also helps
shield the injectors during a frontal impact.
The water pump housing is cast integral with the engine crankcase.
In addition to the belt-driven water pump, VR-6 engine will use
an auxiliary electric pump to circulate water while the engine is
running and during the cooling fan after-run cycle.
In the interest of environmental friendliness, a replaceable oil
filter cartridge is used on the VR-6 engine.
The sump-mounted oil pump is driven via the intermediate shaft.
An oil pressure control valve is integrated in the pump.
*** Crankcase ***
The crankcase is made from Perlitic gray cast iron with micro-alloy.
Two banks of three cylinders are arranged at a 15° axial angle from
the crankshaft.
The cylinder bores are 81 mm in diameter with a spacing of 65 mm
between cylinders. They are staggered along the length of the
engine block to allow the engine to be shorter and more compact
than conventional V-6 engines.
The centerline of the cylinders are also offset from the centerline
of the crankshaft by 12.5 mm.
To accommodate the offset cylinder placement and narrow "Vee"
design, the connecting rod journals are offset 22° to each other.
This also allows the use of a 120° firing interval between cylinders.
The firing order is: 1, 5, 3, 6, 2, 4
*** Cylinder Head ***
The aluminum crossflow cylinder head is manufactured in a permanent
mold casting. The combustion-chamber side of the head is hardened
through a separate chill casting
Twenty stretch bolts are used to retain the cylinder head to the block.
These bolts are accessible even with the camshafts installed.
However, it is necessary to retorque the bolts after installation.
Holes for bolts, numbers 12 and 20 are sleeved to make cylinder head
installation easier.
To help optimize flow through the cylinder head, the area above the
valve seats has been machined. Valve shaft diameter has been reduced
to 7.0 mm during development.
Cylinders 1, 3, and 5 have short intake runners and long exhaust
runners while cylinders 2, 4, and 6 have long intake runners and
short exhaust runners.
A crossflow cylinder head has allowed the use of a single cylinder
exhaust manifold rather than a manifold for each bank.
*** Combustion Chamber ***
The surface of the combustion side of the cylinder head is flat.
The combustion chamber is formed by the shape of the piston head.
Ten different piston designs were tested during development of the
VR-6 engine.
The result of these tests was the selection of a slanted piston
head within eccentric trough. The trough is offset from the center
of the piston by 4.0 mm.
Compression gap height (at TDC) is 1.5 mm. the compression ratio is
10:1.
*** Chain tensioners ***
Operated by oil pressure and spring tension.
The camshafts are driven by a two-stage chain-drive system located
on the flywheel side of the engine.
Chains were selected to drive the valve train in consideration of
a Diesel version of the VR-6 engine.
A single chain (lower) is driven by the crankshaft which, in turn,
drives an intermediate sprocket and shaft at a ratio of 3:4.
The intermediate shaft sprocket drives the camshafts via a double
roller chain (upper) at a ratio of 2:3. A double roller chain is
used to drive the camshaft sprockets because it must transfer more
torque than the lower chain.
The specific gear ratio selection was chosen in order to keep the
camshaft sprocket size small. This helps keep the overall engine
height to a minimum.
Chain tension is maintained by two chain tensioners. The upper
chain tensioner is hydraulically operated by engine oil pressure
and spring tension.
The lower chain tensioner (with mechanical lock) is operated by
spring tension and lubricated with engine oil.
Chain flutter is prevented by guide rails on the slack side of
both chains.
The following is a copy of the original VR6 tech manual, with notes where applicable.
Service Training
Self-Study Program 402
Volkswagen of America, Inc.
Sevice Training
Printed in U.S.A.
Printed 12/91
Part # WSP 521-402-00
All rights reserved. All information contained
in this manual is based on the latest product
information available at the time of printing.
The right is reserved to make changes at any
time without notice.
Always check Technical Bulletins and the mirofiche
system for information that may supersede any
information included in this manual.
*** Introduction ***
Volkswagen has developed a new six-cylinder engine called the VR-6.
This 2.8-liter engine is unique in that the V-angle between cylinder
banks is 15° rather than the 60° or 90° found in most conventional
V-6 engine designs.
The engine features a cast-iron crankcase, one light alloy crossflow
cylinder head with two valves per cylinder operated by chain-driven
overhead camshafts.
All fuel and ignition requirements of the VR-6 engine are controlled
by the Bosch Motronic M2.9 Engine Management System.
This Engine Management System features an air mass sensor, dual knock
sensors for cylinder-selective ignition knock regulation, and Lambda
regulation.
Exhaust gases are channeled through a 3-way catalytic converter.
*** Engine Specifications ***
Engine code: AAA
Design: Four-stroke, internal combustion engine in "Vee"/in-line
Displacement: 2.8 liter
Bore diameter: 81.0 mm
Stroke: 90.0 mm
**note this is listed as 90.3mm elsewhere
"Vee" angle: 15°
Compression ratio: 10:1
Fuel and ignition systems: Bosch Motronic M2.9
Emission control: Lambda control with catalytic converter
The name, VR-6 come from a combination of Vee and the German word
Reihenmotor. The combination of the two can be roughly translated
as "in-line Vee."
Volkswagen has designed the 15° VR-6 to take advantage of
conventional in-line six-cylinder engine features (single cylinder
head, narrow width and excellent balancing) with the advantages
of a V-6 engine design (short overall length and compactness).
*** VR-6 ***
The VR-6 was specifically designed for transverse installation
in front-wheel-drive vehicles. By using the narrow 15° VR-6 engine,
it was possible to install a six-cylinder engine in existing
Volkswagen models.
*** V-6 Conventional Design ***
A wider V-6 engine of conventional design would have required
lengthening existing vehicles to provide enough crumple zone
between the front of the vehicle and the engine, and between
the engine and the passenger cell.
Using the narrow VR-6 engine will help Volkswagen meet current
and future front-end crash standards.
*** Overview ***
The drop-forged steel, six-throw crankshaft runs in seven main
bearings. The connecting rod journals are offset 22° to one
another.
Overhead camshafts (one for each bank of cylinders) operate the
hydraulic valve lifters which, in turn, open and close the 39.0-mm
intake valves and 34.3-mm exhaust valves.
Because of the special VR-6 cylinder arrangement with two rows
of combustion chambers in the same cylinder head, the intake
runners between the two cylinder banks are of varying lengths.
The difference in intake length is compensated in the overhead
intake manifold. Each runner is 420 mm long.
Exhaust gases are channeled from two 3-branch cat-iron exhaust
manifolds into a sheathed Y-pipe. From there, they are channeled
into a single flow before passing over the heated Oxygen Sensor
and then to the catalytic converter.
The oil pump driveshaft is driven by the intermediate shaft.
Fuel injectors of the Bosch M2.9 Engine Management System are
mounted behind the bend of the intake manifolds. Besides being
the optimum location for fuel injection, this location also helps
shield the injectors during a frontal impact.
The water pump housing is cast integral with the engine crankcase.
In addition to the belt-driven water pump, VR-6 engine will use
an auxiliary electric pump to circulate water while the engine is
running and during the cooling fan after-run cycle.
In the interest of environmental friendliness, a replaceable oil
filter cartridge is used on the VR-6 engine.
The sump-mounted oil pump is driven via the intermediate shaft.
An oil pressure control valve is integrated in the pump.
*** Crankcase ***
The crankcase is made from Perlitic gray cast iron with micro-alloy.
Two banks of three cylinders are arranged at a 15° axial angle from
the crankshaft.
The cylinder bores are 81 mm in diameter with a spacing of 65 mm
between cylinders. They are staggered along the length of the
engine block to allow the engine to be shorter and more compact
than conventional V-6 engines.
The centerline of the cylinders are also offset from the centerline
of the crankshaft by 12.5 mm.
To accommodate the offset cylinder placement and narrow "Vee"
design, the connecting rod journals are offset 22° to each other.
This also allows the use of a 120° firing interval between cylinders.
The firing order is: 1, 5, 3, 6, 2, 4
*** Cylinder Head ***
The aluminum crossflow cylinder head is manufactured in a permanent
mold casting. The combustion-chamber side of the head is hardened
through a separate chill casting
Twenty stretch bolts are used to retain the cylinder head to the block.
These bolts are accessible even with the camshafts installed.
However, it is necessary to retorque the bolts after installation.
Holes for bolts, numbers 12 and 20 are sleeved to make cylinder head
installation easier.
To help optimize flow through the cylinder head, the area above the
valve seats has been machined. Valve shaft diameter has been reduced
to 7.0 mm during development.
Cylinders 1, 3, and 5 have short intake runners and long exhaust
runners while cylinders 2, 4, and 6 have long intake runners and
short exhaust runners.
A crossflow cylinder head has allowed the use of a single cylinder
exhaust manifold rather than a manifold for each bank.
*** Combustion Chamber ***
The surface of the combustion side of the cylinder head is flat.
The combustion chamber is formed by the shape of the piston head.
Ten different piston designs were tested during development of the
VR-6 engine.
The result of these tests was the selection of a slanted piston
head within eccentric trough. The trough is offset from the center
of the piston by 4.0 mm.
Compression gap height (at TDC) is 1.5 mm. the compression ratio is
10:1.
*** Chain tensioners ***
Operated by oil pressure and spring tension.
The camshafts are driven by a two-stage chain-drive system located
on the flywheel side of the engine.
Chains were selected to drive the valve train in consideration of
a Diesel version of the VR-6 engine.
A single chain (lower) is driven by the crankshaft which, in turn,
drives an intermediate sprocket and shaft at a ratio of 3:4.
The intermediate shaft sprocket drives the camshafts via a double
roller chain (upper) at a ratio of 2:3. A double roller chain is
used to drive the camshaft sprockets because it must transfer more
torque than the lower chain.
The specific gear ratio selection was chosen in order to keep the
camshaft sprocket size small. This helps keep the overall engine
height to a minimum.
Chain tension is maintained by two chain tensioners. The upper
chain tensioner is hydraulically operated by engine oil pressure
and spring tension.
The lower chain tensioner (with mechanical lock) is operated by
spring tension and lubricated with engine oil.
Chain flutter is prevented by guide rails on the slack side of
both chains.