1. DURABILITY

The combination of Cylinder block & Cylinder head has to withstand :

a. mechanical forces

b. gas forces

c. thermal load in combination with thermal stress

Only the Monoblock-design offers an unlimited flow of cooling water especially in the top area of the cylinder ( see picture 02 )and a stress-free allocation of the cylinder-liners ( see picture 03), while all conventional designed engines have an interruption due to a deck-plate on the cylinder block and cylinder head which is necessary to press the cyl.head-gasket.

In addition there is very limited access for the cooling water also because of the cyl.head-bolts and all the material around. In such designs ( see picture 01 ), the liners receive a "cold" deformation up to 40 microns ( while the STEYR-Monoblock guarantees a "cold & hot " cylinder quality of max. 8 microns ( max. deformation < 0,008 mm )

Conventional Engine Heat radiation STEYR MONOBLOCK cooling system

This results in several significant advantages:

· optimal cooling of the critical "hot spot" ( around 20mm below of the top end of the cylinder )

· no stress between cyl.head and cyl.block due to different materials or temperature levels

· no deformation ( "Ovalisation") on the valve seat rings ð optimal cooling of the valve on the seat ring due to a perfect "all around " contact ð ever lasting valves & seat rings

· lowest oil consumption due a perfect roundness of the cylinder liner – as machined, without of forces, stresses and deformation from the cyl.head bolts

2. SERVICEABILITY

It was the aim of STEYR's Engineering Team to create an engines with superior durability and the

best possible design features in combination with proven, heavy duty materials have been applied

like

· case hardened steel for the cam-shaft

· roller type rocker arms

· hard-metal plated cam-followers, casted from Cobalt-alloyed precision casting

· gas-nitrided cranck-shaft, made from tempered forging steel

· Inlet & Outlet valves from Nimonic (unrivalled heat-and corrosion resistant )

· Valve seats from Stellit-material ( very heat resistant )

· Gallery cooled " oil jet " pistons with steel ring carriers

· Copper-alloyed greycast for exceptional fracture toughness

Ø to achieve - without any compromise – a most durable core engine, most simple to maintain

without any need for repair in the core-power unit !

3. FEED-BACK from the field:

STEYR "Monoblock"-engines are operated in the field since 1990. They are most times used in very tough applications, were high dynamics & response, low weight, high power density and exceptional reliability are asked for.

Just some very interesting applications should be highlighted:

· Military off-road vehicles ( having NATO-approval ) in Austria, Chile, China, France, Germany, Italy, Nigeria, Russia, Sweden, Venezuela….

· Special boats for Police, Coast Guard ( US Coast Guard approved ), Special Forces…

· Light Commercial Vehicles up to 600.000 km in operation

· Commercial operated Water-Ski & Wakeboard-boats with >2000 hrs. / year

· Commercial operated Parasailing boats with >1600 hrs./ year

· Cold start conditions for vehicles down to –45 Celsius

· Hot climate conditions for boat engines up to +45 Celsius

WITHOUT ANY QUESTION: A STEYR IS YOUR BEST CHOICE !

Rudolf Mandorfer

Chief Executive