Fix It

Explore » home» bore » cylinders » how » to » How to Bore Cylinders

---

How to Bore Cylinders

Boring out cylinders is a major part of any engine overhaul, whether the engine belongs to a car, truck or motorcycle. Mechanics who build hot rods bore out cylinders to increase engine displacement and horsepower. Engines that are worn out also get their cylinders bored out to restore functionality and extend service life. Worn cylinder walls permit oil to get into the chamber and cause smoky exhaust and high oil consumption. Loss of compression also results from "out of true" cylinders. Cylinders must generally be bored out at a machine shop with special equipment.

Instructions

1

Remove the engine from the vehicle. The engine must be completely stripped down to its core. Remove all exterior components, cylinder heads, intakes, and exhaust manifolds. Use the engine hoist to lift the engine from the vehicle and mount it to the engine stand.

2

Remove all interior engine parts. Remove the flywheel, core plugs, crankshaft, camshaft connecting rods and pistons. Use the steam cleaner to thoroughly clean the engine on the inside and out.

3

Bore the cylinders. Use the cylinder boring machine to bore the cylinders to the desired specifications. Take special care not to bore the cylinder walls too thin. This runs the risk of making the walls too close to the coolant and oil passages and causing an engine failure.

4

Hone the cylinders. Using the honing tool and stones, smooth out the cylinder walls. This ensures that the pistons and rings travel through each stroke evenly. After honing the cylinders, wash each one out with soapy water to remove any abrasives that have embedded into the walls.

5

Reassemble the engine and install the engine into the vehicle. When reassembling the engine, use new rings on the pistons as the old ones may be worn. You can also take this opportunity to upgrade other engine components like the camshaft, intake manifold and valve train.