Crankshaft end play is a delicate balance.
Too much crankshaft thrust can lead to lead to engine damage, but too little thrust bearing clearance can cause problems as well. If endplay is too tight, the crankshaft can bind and result in serious damage to the engine block.
But tight thrust bearing is relatively easy to fix if you know the right technique.
In today’s video, our friends at Summit Racing continue their Engine Building 101 video series by showing you how to polish your thrust bearing to gain clearance and increase oil film strength on the bearing.
Using an LS engine build as an example, the Summit team removes the bearing and crankshaft from the engine to their tabletop. With emery cloth and oil, they remove a small amount of surface area from the thrust bearing by using a figure-eight pattern.
After cleaning the bearing with acetone, they use a micrometer to measure bearing thickness and do some additional work to achieve the final clearance needed for a high-load engine.