Ford E9TZ-6108-DB Piston

Prior to removing the piston and connecting rod assemblies, the cylinder heads, oil pan, and oil pickup must be taken off. First, completely remove the ridge at the top of each cylinder using a ridge reaming tool, following the manufacturer's instructions, as failure to do so may result in piston breakage. After the ridges are removed, turn the engine upside down so the crankshaft is facing up. Before removing the connecting rods, check the endplay with feeler gauges, ensuring the play is eliminated; if the endplay exceeds the service limit, new connecting rods may be necessary. Check the connecting rods and caps for identification marks, and if they are not marked, use a small center punch to create indentations. Loosen each connecting rod cap nut half a turn until they can be removed by hand, then take off the number one connecting rod cap and bearing insert, ensuring not to drop the bearing insert. To protect the crankshaft journal and cylinder wall, slip a short length of plastic or rubber hose over each connecting rod cap bolt before removing the piston. Push the connecting rod and piston assembly out through the top of the engine, using a wooden hammer handle to assist, and if resistance is felt, verify that all ridge material has been removed. Repeat this process for the remaining cylinders, and after removal, reassemble the connecting rod caps and bearing inserts in their respective rods, installing the cap nuts finger tight to prevent accidental damage to the bearing surfaces.

Before installing the piston and connecting rod assemblies, ensure the cylinder walls are clean, the top edge of each cylinder is chamfered, and the crankshaft is in place. Remove the connecting rod cap from the number one connecting rod, take out the old bearing inserts, and wipe the bearing surfaces with a clean, lint-free cloth. Clean the back side of the new upper bearing half and lay it in place in the connecting rod, ensuring the tab fits into the recess without hammering it in or nicking the bearing face. Clean the back side of the remaining bearing insert and install it in the rod cap, again ensuring the tab fits into the recess without applying lubricant. Position the piston ring gaps at intervals around the piston and slip a section of plastic or rubber hose over each connecting rod cap bolt. Lubricate the piston and rings with clean engine oil, attach a piston ring compressor, and leave the skirt protruding about 1/4-inch to guide the piston into the cylinder. Rotate the crankshaft until the number one connecting rod journal is at bottom dead center and apply engine oil to the cylinder walls. With the notch or arrow on top of the piston facing the front of the engine, gently insert the piston/connecting rod assembly into the number one cylinder bore, resting the bottom edge of the ring compressor on the engine block, and tap the top edge to ensure contact. Carefully tap on the top of the piston with a wooden hammer handle while guiding the connecting rod into place on the crankshaft journal, maintaining downward pressure on the ring compressor to prevent the piston rings from popping out. Once installed, check the connecting rod bearing oil clearance before permanently bolting the rod cap in place. Cut a piece of Plastigage slightly shorter than the width of the connecting rod bearing and lay it on the number one connecting rod journal. Clean the connecting rod cap bearing face, remove the protective hoses, and install the rod cap, ensuring the mating marks align. Tighten the nuts to the specified torque in three steps, avoiding any crankshaft rotation during this process. Remove the rod cap carefully to avoid disturbing the Plastigage, compare the width of the crushed Plastigage to the scale on the container to obtain the oil clearance, and ensure it meets specifications. If the clearance is incorrect, check for dirt or oil between the bearing inserts and the connecting rod or cap, and recheck the journal diameter. Scrape off any Plastigage material carefully without scratching the bearing, then apply a uniform layer of clean moly-base grease or engine assembly lube to both bearing faces. Slide the connecting rod back into place on the journal, remove the protective hoses, install the rod cap, and tighten the nuts to the specified torque, again working up to it in three steps. Repeat the procedure for the remaining piston/connecting rod assemblies, keeping all components clean and ensuring the correct piston is used for each cylinder with the notch facing the front of the engine. After all assemblies are installed, rotate the crankshaft by hand to check for binding, and finally, check the connecting rod end play against specifications to ensure it is correct, addressing any issues with resizing if necessary.

Before the inspection can be done, the piston/connecting rod assemblies have to be washed, the original piston rings have to be taken off the pistons and new piston rings always have to be installed. The rings on the pistons should be retrieved with a piston ring installation tool without scratching the ring or piston. Remove all the carbon deposits that stick to the head of the piston with the aid of a hand held wire brush or fine emery cloth, but it is recommended that you avoid using a wire brush that has been fixed in a motor since doing this will erode the surface of the piston. Carbon build-up in the ring grooves needs to be cleaned, using a piston ring groove cleaner, or as a last resort, a section of an old ring, should not scrape any metal off the grooves nor cause any damage. Upon the removal of the deposits, wash the piston/rod assemblies with solvent and blow the assemblies using compressed air such that the oil return holes are clear. If pistons and the cylinder walls are not badly scratched and worn and engine block has not been rebored, new pistons may not be needed, however always new piston rings should be fitted in the engine during rebuild. All pistons must be examined for evidence of cracks, scoring or scutting, particularly in areas where there may be signs of overheating or abnormal combustion; also patterns of corrosion suggesting coolant leaks. Check the side clearance of each of the pistons rings by using the feeler gauge on three points of each of the grooves and making sure the correct ring is used in each groove. To check the piston-to-bore clearance some bore measurements and piston diameters should be made in order to detect the accurate clearance. In the event that the clearance is outside the specifications, then the block should be rebored, pistons and piston rings changed. It can be checked that phenomenon of piston-to-rod clearance by attempting to twist the piston and rod in opposite directions; which would show definite looseness that would demand adjustment. If pistons are to be separated from the connecting rods, then the latter has to be sent for assessment of bend and twist at an automotive machine shop. Also, discover the connecting rods are cracked or damaged in some way, or can be slightly loosened so that the rod caps can be removed for inspection of the bearing surfaces for any nicks or scratches and bearings replaced before proceeding.

With the arrow or notches on top of the piston facing the front of the engine, gently insert the piston/connecting rod assembly into the number one cylinder bore and rest the bottom edge of the ring compressor on the engine block.

Slip a short length of plastic or rubber hose over each connecting rod cap bolt to protect the crankshaft journal and cylinder wall as the piston is removed.

Position the piston ring gaps - Lubricate the piston and rings with engine oil.

Clean the back side of the other bearing insert, install it in the rod cap, ensure the tab on the bearing fits into the recess in the cap, and do not apply any lubricant. The mating surfaces of the bearing and connecting rod must be perfectly clean and oil-free when assembled.

If ridges are present, you should use a ridge reamer to eliminate them.

No, new pistons may not be necessary, but new piston rings are recommended for engine rebuilding.

If the pistons must be removed from the connecting rods for any reason, they should be taken to an automotive machine shop. While they are there, have the connecting rods checked for bend and twist, since automotive machine shops have special equipment for this purpose. Note: Unless new pistons or connecting rods must be installed, do not disassemble the pistons and connecting rods.