BF Products in Focus 2nd edition 09/2014 (082016) Item number 50 020 042-02 Edited by: Motorservice, Technical Market Support Layout and production: Motorservice, Marketing DIE NECKARPRINZEN GmbH, Heilbronn This document must not be reprinted, duplicated or translated in full or in part without our prior written consent or without reference to the source of the material. All content including pictures and diagrams is subject to alteration. No liability accepted. Published by: © MS Motorservice International GmbH 2 | Products in Focus Technology and service with tradition Contents Page Crankshafts 4 Camshafts 6 Connecting rods 8 Cylinder heads 10 Water pumps 12 Oil pumps 14 Flywheels 16 Crankcases 18 Products in Focus | 3 Crankshafts Product range • Forged crankshafts for: - truck engines - industrial engines - gas engines - engines for agricultural and forestry machines • Crankshaft accessories: - toothed wheels - bearing rings - counterweight bolts Crankshafts in Focus • The crankshaft in the engine has the • To ensure high quality standards, most the crankshaft accessories are also task of converting the up and down BF crankshafts are produced on own replaced. movement of the pistons into a rotary tools and are subject to stringent motion with the aid of the connecting checks. rods. This torque is transmitted to the • Due to the high levels of stress flywheel. encountered in the utility vehicle sector, • Two types of crankshaft are produced, BF follows the OE specifications and cast and forged, with integrated or offers predominantly forged bolted-on counterweights. The pistons, crankshafts. connecting rods and crankshaft together • To ensure the durability of the newly form the crank mechanism. installed crankshaft, we recommend that 4 | Products in Focus Forged counterweights Bolted-on counterweights Twisted connecting rod journals e. g. OM 611 4-cylinder in-line engine e. g. OM 335 6-cylinder in-line engine To allow for other crankshaft angles at the connecting rod journals, the crankshaft is heated again after forging and twisted at the main bearing points. e. g. OM 906 6-cylinder in-line engine Offset connecting rod journals Two connecting rods per connecting rod e.g. OM 501 6-cylinder V engine journal e.g. OM 422 8-cylinder V engine Products in Focus | 5 Camshafts Product range • Camshafts for truck, industrial and gas engines • Engines for agricultural and forestry machines • Camshaft accessories, such as - valve tappets - push rods - rocker arms - rocker arm brackets Camshafts in Focus • The camshaft is driven by the crankshaft the push rods and rocker arms, in turn • To preserve the durability of newly via the drive gear, and in turn controls governing the exchange of gas in the installed camshafts, we recommended the valve train of the engine. The engine. replacing the following parts at the same camshaft helps to ensure that the intake • New generation truck engines have time: and exhaust valves open and close at overhead camshafts. In-line engines - tappet pre-determined times. have a maximum of two camshafts, - push rods • The duration of opening, valve stroke V engines may be fitted with as many as - gasket set and movement of the valve on opening four camshafts. - camshaft bearings and closing are determined by the shape • The camshafts are subject to bending - rocker arm of the cam. and torsion forces. To withstand these • Camshafts are fitted below the high levels of strain over the long term, crankcase in approximately 60% of all the camshafts in the BF product range truck and industrial engines. The intake have been designed with high strength and outlet cams control the intake and properties. Camshafts may be cast or exhaust valves of the cylinder head via forged, depending on their intended purpose. 6 | Products in Focus Standard camshaft Intake camshaft Outlet camshaft The camshaft actuates both the intake and If two camshafts are used, the intake The exhaust valves are actuated by the exhaust valves. camshafts actuate the intake valves only. outlet camshaft as well as the intake To ensure maximum cylinder fill, the cam camshaft. Exhaust valves often have stroke of the intake camshafts is typically a shorter cam stroke than intake greater than that of the exhaust camshafts, which can be attributed to the camshafts. higher pressure difference at the exhaust for discharging combusted gases. 2 3 1 4 5 1 Valve 2 Valve-spring 3 Rocker arm 4 Push rod 6 5 Tappet 6 Camshaft Combined camshaft Overhead camshafts Bottom-mounted camshafts 3 cams for PLD fuel injection systems: Where camshafts are overhead, the Where camshafts are bottom-mounted, • intake cams valves are opened directly by the cams the tappets and push rods transfer the • outlet cams via the tappets, rocker arms or finger stroke of the camshaft to the rocker arms. • cams as pump and nozzle unit drive type rockers. Overhead camshafts are The rocker arms push open the valves used only with multiple cylinder against the force of the valve springs. heads. Products in Focus | 7 Connecting rods Product range • Parallel and trapezoidal connecting rods - Cracked - Toothed - Sawed • Accessories: - connecting rod bolts - conrad bush Connecting rods in Focus • Connecting rods form the link between • The connecting rod is mounted on the • Connecting rods must be replaced if they the crankshaft and the pistons and crankshaft crankpin via conrod bearing are broken or bent, or if the mountings of transfer the gas and inertial forces to the shells. The large connecting rod eye is the connecting rod are deformed. crankpins on the crankshaft. The divided for mounting on the crankshaft. If the other connecting rods are free from connecting rod pushes and pulls the The connecting rod often has a bore damage, the connecting rods in utility piston into and out of the cylinder. between the small and the large vehicles can also be replaced • The small, undivided connecting rod eye connecting rod eye for supplying the individually, providing the same type is on the piston side for mounting the piston pin with lubricating oil. used. piston bolt has a connecting rod bearing • The connecting rod is forged from steel, bush. with either alloyed steel or annealed steel used depending on the strain. 8 | Products in Focus Straight separation Angled separation Straight and angled separation Cracked joint faces Milled or polished joint faces For very large crankpins, connecting rods Cracked connecting rods are initially Another procedure for producing the may be separated at an angle. This is produced as a single unit, then given break connecting rod bearing cap is separation necessary to allow the connecting rod to lines (sinter rods) or laser notches (steel or cutting. The large connecting rod eye is slide into the cylinder, in spite of the large connecting rods) and split (cracking) into cut apart, the joint faces are then milled or connecting rod eye. When using two parts. Both parts are screwed together polished. The connecting rod bearing cap connecting rods with angled separation, when the connecting rods are assembled, is then fixed with locating bolts or pins. the installation position must be observed, with the point of fracture ensuring that the especially in in-line engines. rods fit together precisely. Connecting rods and connecting rod caps must always be used together on account of their breakage geometry, they cannot be interchanged. Cracked connecting rods offer more advantages in terms of strength, cost and production accuracy. Once assembled, the joint faces are barely visible. Connecting rods and connecting rod caps fit together very precisely, thus allowing maximum force transmission. Parallel and tapered connecting rods Ever-increasing combustion pressures are Parallel Usable area increasing the stresses on piston pin connecting rod mountings on connecting rods. To better absorb higher forces, the usable area of the connecting rod bearings has been increased by using tapered connecting rods. Tapered connecting rod Products in Focus | 9 Cylinder heads Product range • Comprehensive range of cylinder heads for all conventional truck engines and to suit various Euro standards. • Accessories: - cylinder head bolts - valve springs - valve spring retainers - valves - valve seat inserts Cylinder heads in Focus • In combustion engines, the cylinder • The cylinder head is one of the more • The combustion process that takes place head sits above the pistons in the complex components of a motor, in the cylinder exerts a high amount of combustion chamber. requiring complex manufacturing force on the cylinder head, so it is vital • The cylinder head is positioned above processes. In addition to holding the that the tightening torques of cylinder the cylinder block and the head gasket. described components, the cylinder head bolts always match those specified • The cylinder head accommodates the head also has to fulfil the following by the manufacturer. key components for mechanical control tasks: • The tightening sequence of the cylinder of the gas exchange, including: - sealing the combustion chamber head bolts is important for preventing - intake and exhaust ducts for charge - absorbing the combustion power deformations. If the manufacturer’s exchange process - supplying the moving components of instructions are not observed, harmful - valves and accessories the valve train deformations may occur on the cylinder - rocker arms or finger type rockers - heat dissipation through coolant head, on the cylinder of the cylinder - tappets channels and cooling liquid with water- head gasket or on the valve seat inserts. cooled motors, or via large-scale cooling fins (blower) with air-cooled motors. 10 | Products in Focus Single cylinder heads Multiple cylinder heads • The majority of truck engines feature Multiple cylinder heads are typically used single cylinder heads. in passenger vehicles and in new • There are various types, e.g. water- generation truck engines. V engines with cooled cylinder heads from grey cast multiple cylinder heads have one cylinder iron (see picture left) and air-cooled head for each cylinder line. In engines with cylinder heads from aluminium multiple cylinder heads, camshafts are (see picture right).