Acura 13101-PH7-000 Piston A (STD)

Prior to removing the piston and connecting rod assemblies, the cylinder head(s), oil pan, oil pump pick-up tube, and bearing cap bridge must be taken off. Use your fingernail to check for any ridge at the upper limit of ring travel, approximately 1/4-inch down from the top of each cylinder. If ridges are present due to carbon deposits or cylinder wear, they must be completely removed with a ridge reamer before the pistons are taken out to avoid breakage. Once the ridges are cleared, turn the engine upside-down with the crankshaft facing up. Before removing the connecting rods, check the side clearance with feeler gauges, ensuring the play is eliminated. If the endplay exceeds the service limit, new connecting rods may be necessary, and if new rods or a new crankshaft are installed, the endplay might need to be adjusted. Mark the connecting rods and caps with a center punch to indicate their associated cylinders, as the existing numbers indicate rod bore size. Loosen the connecting rod cap nuts gradually until they can be removed by hand, then take off the number one connecting rod cap and bearing insert without dropping the insert. To protect the crankshaft journal and cylinder wall during piston removal, slip a short length of plastic or rubber hose over each connecting rod cap bolt. Remove the bearing insert and push the connecting rod/piston assembly out through the top of the engine, using a wooden hammer handle to apply pressure on the upper bearing surface. If resistance is encountered, ensure all ridges have been removed. Repeat this process for the remaining cylinders. After removal, reassemble the connecting rod caps and bearing inserts in their respective rods and install the cap nuts finger tight to prevent accidental damage to the bearing surfaces. Avoid separating the pistons from the connecting rods.

New piston rings constitute the only material to use for installation during reassembly after the inspection process begins. The piston/connecting rod assemblies require cleaning before obtaining new piston rings and removing the original rings from pistons. The piston ring tool must be employed to take out the rings from each piston with great caution to prevent damage. A hand-held wire brush together with fine emery cloth should be used to remove all carbon residue from the top of the piston. The use of wire brushes attached to drill motors is not recommended since this could damage the soft piston material. A piston ring groove cleaning tool needs to be used to eliminate carbon buildup in the ring grooves instead of relying on a portion of the old ring since this method ensures carbon extraction without hurting the metal structure. The cleaning process should finish with air compression drying which must clear all openings in the rods including oil return holes and oil holes. The replacement of new pistons becomes unnecessary unless the engine block needs reboring as a matter of damage prevention though new rings must be installed for each rebuild of the engine. You should inspect each piston to detect cracking, scoring, burned areas alongside scuffing and holes since these overheating signs might need you to examine the cooling followed by lubrication systems thoroughly. The detection of small pits on engine parts indicates coolant leakage which requires immediate attention to stop its recurrence during engine rebuild. Check piston ring side clearance through multiple measurements with a new piston ring and proper feeler gauge positioning around each groove while selecting the correct ring for every groove and excessive clearance requires new pistons. The bore measurement along with the piston diameter should match correctly to determine piston-to-bore clearance and standard markings on engine block and pistons should be checked. An angle-90-degree measurement of piston skirt across the surface will determine piston-to-bore clearance by subtracting piston diameter from bore diameter; excessive clearance requires block rebores along with new pistons and rings. The inspection of piston pin-to-rod clearance requires twisting the piston and rod together in different directions since noticeable movement suggests significant wear that requires resizing with new pins at a professional automotive machine shop. Connectors with pistons should be submitted to automotive machine shops for detecting bend and twist before proceeding with disassembly unless replacing parts. The inspection of connecting rods should include a check for cracks and damage followed by rod cap removal to evaluate bearing surfaces for nicks and scratches before replacing old bearings while tightening caps finger tight until new rods need installation during rebuilding campaigns for connecting rod knock.