UMP-4215 engines have a traditional design, which has been produced by Volga Motors OJSC for a long time
- an aluminum cylinder block with a lower camshaft, a valve stem drive through rocker arms, a camshaft gear drive, an aluminum head with intake and exhaust channels on one side.
The main structural difference between the 4215 engines and the ZMZ-4025 and ZMZ-4026 engines is that they have an aluminum block with cast thin-walled liners made of special wear-resistant cast iron (ICHG-ZZM).
The nominal diameter of the sleeves is 100 mm. The piston stroke remains the same -92 mm.
The working volume of the engine cylinders has been increased by increasing the piston diameter
Longitudinal section of the engine is shown in the figure.
An aluminum clutch housing is bolted to the rear end of the block.
Pistons are cast from aluminum alloy. Each of them has two compression and one oil scraper rings.
Compression rings - cast iron, top - chrome-plated, bottom - tin-plated.
Piston pins are of a floating type, they are held from axial movement by retaining spring rings.
Steel, forged, I-section connecting rods with a split lower head, the cover of which is fastened with two bolts and nuts.
A bronze bushing is pressed into the upper (piston head) of the connecting rod.
Crankshaft cast iron, cast, full support, with counterweights, dynamically balanced assembly with a flywheel and installed in the cylinder block on five split main plain bearings.
The main and connecting rod bearings are made in the form of liners made of steel tape coated with anti-friction aluminum-tin alloy.
The shaft is held against axial displacement by two thrust rings, which are installed on both sides of the front main bearing.
The ends of the crankshaft are sealed with rubber cuffs. A hub is pressed on the front toe of the crankshaft, to which a damper pulley is bolted.
Cylinder head cast from aluminum alloy. Cast iron seats and ceramic-metal valve bushings are pressed into it.
The head is attached to the block with ten studs and nuts through a metal-asbestos gasket. On the right side, the exhaust manifold and intake pipeline are attached to the head.
Camshaft cast iron, installed in bored holes in the lower part of the cylinder block.
At its front end, on the key, a textolite or polyamide helical drive gear is installed.
The camshaft cams, when it rotates, act on cylindrical pushers that are installed in the holes of the block.
Aluminum push rods with steel spherical tips actuate valve rockers mounted on a common fixed steel axle.
On the short arm of the rocker there is a screw with a lock nut for adjusting the clearance in the valve actuator.
Thin-walled bronze bushings are pressed into the rocker holes.
The valves are made of heat resistant steel.
Each valve is equipped with two right-handed and left-handed springs and is installed in a ceramic-metal guide bush made of sintered copper-iron-graphite powder with molybdenum disulfide.
The valve stems are sealed with rubber baffle caps that prevent oil from entering the combustion chambers.
The top of the block head is closed with a stamped steel cover.
Combined lubrication system - under pressure and spray.
Under pressure, the main and connecting rod bearings of the crankshaft, camshaft bearings, rocker bushings, upper tips of the push rods are lubricated.
The gears of the camshaft drive and the drive of auxiliary units are lubricated with a jet of oil, and the rest of the parts are splash lubricated.
The cylinder walls are additionally lubricated by a jet of oil, which is ejected from the hole in the lower head of the connecting rod.
The gear oil pump is driven together with the ignition distributor sensor by a screw gear from the camshaft.
The pump body is aluminum, and its working spur gears are made of sintered metal.
Oil is drawn by a pump from a stamped steel sump through a mesh oil intake, then it passes the pump, a full-flow filter and is fed into the oil line.
The oil pressure in the system is limited by the pressure reducing valve.