Crankshaft bearings provide a lot of information about the shape of the thrust bearing and its diameter. The dimension of a bearing can be measured with a nonium saddle like this or by exact measurement with a ruler. Once you have determined the bearing dimensions, you can use the bearing locator function to find out if your bearing is larger.
Each engine has its own bearing clearance, so the measurement method does not change, but you have the option of measuring both the bearing clearance and the thrust bearing with the Honda B18C engine you get.
So we have to talk about the thrust bearing, which is the part of the engine that is responsible for the performance, and not just the bearing clearance.
The thrust bearing is used to support the crankshaft and to avoid over movements. The reason we need thrust bearings is that they eliminate movement forward, backward, and longitudinally in and out of the crankshaft when the engine is running, or when a clutch is engaged or disengaged. Crankshaft thrust carriers offer a good degree of thrust clearance as well as speed and torque indication.
Depending on the engine design, the thrust bearing can be placed on top or bottom of the crankshaft or integrated into a specific main bearing unit.
This creates a slight cone at the line parts, which creates an oil wedge that supports the crank pin.
The thrust bearing now has a tapered edge that conveys the oil wedge, and its surface is generally flat, facing the flat thrust range of the crank. Since oil is fed into the thrust bearings in the crankshaft gap, they also have grooves that allow oil from the radial bearings to seep into the thrust bearing surface and create a lubricating film.
The thick wall shell bearings mounted on the engine have a clearance that can be adjusted by installing a washer between the semi-bearing and the thrust bearing surface.
Heavy loads on the engine can lead to wear on the main bearing and therefore lubricating oil cannot be retained. The ovality of the crankpins can lead to an increase in the freedom of storage and to the obliteration of the bearing.
The crankpin is measured by the external micrometer at three different positions along the length of the bolt. The measurement of the crankpin can be performed with the inner and outer micrometers at the same position on the crank pin.
It is very difficult to measure the play radially because it has to be done with tapered roller bearings. Instead, define the inner play with a tapered roller bearing and measure in the radial direction. The best method of measuring the clearance of the bearing is to use an external micrometer, where the bearings have a torque as shown.
However, this method is not suitable for large, heavy industrial bearings and will not work with them. IRC is total motion and you can check the tapered roller bearing by hand, but it will cause a lot of damage to the bearings.
It is very difficult to measure the play in a radial direction because it is done with tapered roller bearings. Instead, define the inner play with a tapered roller bearing and measure it from the outside.
The only truly reliable way to do this is to install a flywheel on the back of the crank and use a tool that holds the flywheel to block the crankshaft. You can check the tapered roller bearing manually, but this method does not work with large industrial bearings. Dipstick – bearing clearance is also a good way to control the main bearing to prevent a crank from turning off the block and the rod spigot when damaged by plastinate.
The thrust of the main bearing directs the load of the engine, also called thrust, from the clutch drive to the front and back. The thrust decreases when you drive hard and heavy with a clutch, especially in hard – and – heavy – driven vehicles.
If you are too tight or loose, you can replace the thickness of the thrust bearing to meet the desired specifications.
Before installing the main crankshaft cap, you must thoroughly lubricate the exposed main bearing and thrust bearing surface. Once you have positioned the main bearings and caps, tighten to a minimum (approx. 10 – 15 lbs lb) after factory setting – recommended tightening sequence. Instead of simply installing your main bearings and thrust bearings, spend a few extra minutes tightening both the main caps and fasteners to factory-set torque values to maximize thrust – bearing life.
Always follow the recommendations of your crankshaft and bearing manufacturer when using aftermarket components. GM recommends a tightening sequence of at least 10 – 15 lbs after factory setting.
A more accurate way to measure this is to attach a dial indicator that reads the crank snout and the rear crank flange. Pull the crank forwards and backward and mount it on the back of the recorder ring and record its measurement by holding the cranks forward or backward under slight pressure to eliminate thrust clearance.
Attach it to the top of the crank and rotate it to note the dial display while holding it forward / backward under the slightest pressure, eliminating thrust spaces.