How is the maximum oil pressure determined?
The oil pressure limit is determined from load or crankshaft speed measurements that are already available in the engine control system. These measurement data can be sent to the instrument subsystem via a MUX system as described with respect to Fig. 8.5 and over an IVN.
How to split the case and replace crank bearings?
There’s your transmission, your crank. We’re going to go ahead and pull the transmission out. That’s your countershaft, your main shaft. Make sure and try to keep them all together, all your shift forks, then lay them out. Make sure and check for washers in your shift drum also. Now is a good time to check for wear on your cogs.
What’s the difference between oil film and static bearing clearance?
In a running engine, cylinder pressure pushes downward on the piston, reducing that 0.001-inch figure. A loaded connecting rod at peak cylinder pressure will reduce that oil film clearance to as small as 0.0002-inch. With a static bearing clearance of 0.002-inch that means the upper half of the rod bearing has 0.0198-inch worth of clearance.
What happens to the bearings when oil pressure goes down?
But if there is a sudden loss of oil pressure and flow, especially at high RPM, the protective film can disappear in an instant. Once that happens, you get metal-to-metal contact between the bearing and journal surfaces, which causes scuffing, increased friction and heat.
How big is the oil film clearance on a cylinder?
A loaded connecting rod at peak cylinder pressure will reduce that oil film clearance to as small as 0.0002-inch. With a static bearing clearance of 0.002-inch that means the upper half of the rod bearing has 0.0198-inch worth of clearance.
There’s your transmission, your crank. We’re going to go ahead and pull the transmission out. That’s your countershaft, your main shaft. Make sure and try to keep them all together, all your shift forks, then lay them out. Make sure and check for washers in your shift drum also. Now is a good time to check for wear on your cogs.
What causes oil windage in a crankcase?
As blow-by saturates the crankcase atmosphere with super-heated oil, it chokes the air inside the crankcase, coating the crank, rods and pistons with a heavy layer of lubricant – far more than these parts need. Of course, a direct contributor to oil windage is excess/over-filled oil levels.
How does crankcase pressure affect engine oil leak?
Engine Crankcase Pressure and Engine Oil Leaks. Another factor effecting crankcase pressure is Blow-by. Blow-by is when combustion gases leak past the seal created by the piston, piston rings and cyliner wall. These blow-by gases move past the seal and into the crankcase area, and this will increase the crankcase pressure.
What happens when you blow by the crankcase?
Windage can slow down your engine’s operation and, again if left unchecked, can cause unusual wear patterns in the cylinder walls. As blow-by saturates the crankcase atmosphere with super-heated oil, it chokes the air inside the crankcase, coating the crank, rods and pistons with a heavy layer of lubricant – far more than these parts need.