Mercury E6TZ-6108-FB Piston

Before full disassembly of the piston and connecting rod assemblies there are few components that need to be detached,the cylinder head, the oil pan and the oil pump. First, eliminate the ridge at the top of each cylinder utilizing a ridge reaming tool because the existence of this ridge is dangerous to the pistons when undertaking the removal processes. After clearing the ridges, inversion of the engine is done with crank shaft upwards. When disconnecting the connecting rods, it will be necessary to check the end play with feeler gages; it should readily be possible to insert the thickness of a feeler gage between the first connecting rod and the crankshaft throw; if the end play is excessive, it may be necessary to replace the connecting rods. Locate the connecting rods and the caps with the marks; in case the latter ones are missing, the engineer shall apply a center punch to put an indentation of the cylinders' number. Turn the connecting rod cap nuts gradually to be unfastened by hand; then take off the first connecting rod cap and the bearing insert without dropping the latter. For each of the connecting rod cap bolts to be removed, slip in a short length of plastic or rubber hose over the bolt before gently pounding the connecting rod/piston assembly out through the top of the engine, using a wooden or plastic hammer handle only. In case of resistance make sure that all the ridge material has been cleared. Perform it for the rest of the cylinders and once they are removed, fit back the connecting rod caps and bearing inserts to their corresponding rods and tighten the cap nuts only with fingers to avoid the wear and tear of the bearing surfaces.

Before the inspection process can be done the piston/connecting rod assemblies have to be cleaned and most especially the original piston rings should be taken off the pistons during the inspection and replacement process to ensure that new piston rings are always used. Take the rings using a piston ring expander in order to remove them from the pistons without damaging them. Clean up all that carbon from the crown of the piston using a hand-held wire brush or fine emery cloth so as not to damage the soft material of the piston through work of a wire brush mounted in a drill motor. Use a tool to clean the piston ring groove that is a metallic scraper to remove carbon from the ring grooves, or a part from the old piston ring if a tool cannot be obtained but make sure do not bend the metal or scratch the grooves. If the deposits are removed, clean the piston/rod assemblies with the solvent, blow with the compressed air to dry while making sure that the oil return holes are free. Some conditions that may not require new piston but require the new pistons rings are; If the pistons are not damaged or excessively worn and if the engine block is not rebored then new set of pistons may not be necessary but new set of piston rings must always be used when reconditioning the engine. Check each piston for cracks, scoring, scuffing, holes and burned areas since these are sings of overheating, abnormal combustion or spark knock; all of which require a detailed examination of the cooling and lubrication systems. Pinpoint corrosion can indicate coolant seepage that must be corrected to avoid a recurrence in the rebuilt engine. The piston ring side clearance must be measured with feeler gauges in several positions along each groove while using the correct ring for the groove and if the side clearance is beyond permissible limits, new piston will have to be used. A piston-to-bore clearance should be determined by measuring the bore and piston diameter correctly and calculating the clearance; if the clearance is too great the block will have to be rebored, with new pistons and rings. Check the piston to rod clearances by rotating both the piston and the rod and if there's too much play the assemblies have to be machined, often a task for an automotive machine shop, rebore and new pins may be required. However, if pistons have to be, for instance, removed from the connecting rods, they should also be taken to an automotive machine shop to check for bend and twist. Last, you should inspect connecting rods for cracks and other damages-to do that remove the rod caps, check the bearing surfaces for nicks, or scratches, replace the old bearings, and, finally, fasten the caps.

Careful should be taken to see that the cylinder walls are free from rust and the top edge of each cylinder are deburred while fixing the piston and the connecting rod, crank shaft must be fixed. Pry the connecting rod cap off, on the number one connecting rod withdraw the old bearing inserts and clean the bearing surfaces thoroughly using a clean, lint-free cloth. Before final assembly, it is advisable to clean the back side of the new upper bearing half and put it in place in the connecting rod such that the tang will slide into the correct slot without having to hammer it or damage the bearing face in the process. Clean the back side of the other bearing insert and put it into the rod cap such that the tang rests on the slot but you do not apply any lubrication. Place the gaps of the piston ring around the piston and slide a part of a plastic or rubber hose over one of the connecting rod cap bolts. Apply clean engine oil on the piston and rings, fit on the piston ring compressor; keep a 1/4-inch lip on skirt to ease the piston into the cylinder. Turn the crankshaft anticlockwise until the number one connecting rod journal coincides with bdc and lubricate the cylinder walls with engine oil. With the notch on top of the piston facing the front of the engine, gently position the piston/connecting rod assembly into number one cylinder bore so that the bottom edge of the ring compressor lays on the engine block, tap the top edge of the ring compressor. Gently strike the top of the piston lightly with a wooden or plastic hammer handle and at the same time, still holding the ring compressor down, smooth the connecting rod over the crankshaft journal and align the piston boss with the next corresponding hole in the cylinder liner. After the assembly has been installed than check the oil clearance of the connecting rod bearing before final tightening of the rod cap. Take a strip of Plastigage somewhat shorter than the bearing width of the connecting rod and place it on the number one connecting rod journal, next, clean the connecting rod cap bearing face, and remove the protective hoses before fitting the rod cap in a manner that the marked faces align. Ensure to tighten nuts to the required torque in three stages without causing rotation of the crankshaft. Take off the rod cap gently, because the movement of Plastigage may be affected, compare the width of the squashed Plastigage with that marked on the container to get the oil clearance, and check the required value. Incase the clearance is incorrect, feel for dirt or oil lying between the bearing insert and the connecting rod or any cap on it, also measure the journal diameter again. Remove any Plastigage from the rod journal and part of the bearing face gently without causing any scratch and then apply a thin film of new moly-base grease or fresh engine assembly lube on both the surfaces. Simply slide the connecting rod back into the position on the journal, detach the protective hoses, screw the rod cap back into position and finally tighten the nuts to the torque; but just like in the initial tightening of the nuts, gradually increase the torque in sequences of three. Perform the same for rest of the piston-connecting rod assembly, holding the bearing inserts and connecting rods clean, make sure to fit right piston at each cylinder with the notch in front of the engine and lubricate the piston well and then fit the ring compressor correctly over it. After all assemblies are installed, take the crankshaft and try to rotate it by hand to check for excessive binding; finally, check the con rod end float by feeling the movement at the big end, the measured endfloat should be correct; if new con rods or a new crankshaft was assembled to the engine, the endfloat may require adjustment, by taking the rods to an automotive machine shop for reboring.

Before installing piston/connecting rod assemblies, ensure clean cylinder walls, chamfered top edge of each cylinder, and crankshaft in place. Remove cap from end of number one connecting rod, wipe original bearing inserts' surfaces. Place upper and lower bearing inserts in connecting rod and cap, align tabs. Position piston ring gaps, lubricate piston and rings with oil. Use ring compressor to insert assembly into number one cylinder bore, tap piston into place, guide connecting rod onto crankshaft journal. Check connecting rod bearing oil clearance with Plastigage before bolting rod cap. Tighten nuts to specified torque, check Plastigage for oil clearance, scrape off traces if correct. Apply moly-base grease or assembly lube to bearing faces, slide connecting rod back into place. Repeat procedure for remaining pistons/connecting rods. Rotate crankshaft to check for binding, verify connecting rod endplay, resize rods if necessary at machine shop.

To prepare for piston/connecting rod assembly removal, check for ridges at the upper limit of ring travel using your fingernail and, if present, use a ridge reamer to eliminate them before attempting to remove the piston/connecting rod assemblies. Ensure the tool doesn't cut into the ring travel area more than 1/32-inch. Once ridges are addressed, turn the engine upside-down with the crankshaft facing up. Before removing connecting rods, check the side clearance with a dial indicator or feeler gauges, ensuring it falls within the specified limits; excessive clearance may require new connecting rods or crankshaft repair. Mark connecting rods and caps for identification, then gradually loosen the connecting rod cap nuts or bolts and remove them by hand. Remove the connecting rod cap and bearing insert, protecting the crankshaft with hose sections if studs are present. Push the connecting rod/piston assembly out through the top of the engine using a wooden or plastic hammer handle, ensuring any resistance is double-checked for ridge removal. Repeat for remaining cylinders. After removal, reassemble connecting rod caps and bearing inserts in their respective rods, securing cap nuts finger tight, and avoid separating pistons from connecting rods.

Clean piston/rod assemblies, replace piston rings. Use ring installation tool to extract rings without damaging pistons. Remove carbon deposits from piston tops with wire brush or emery cloth. Clean ring grooves with groove cleaning tool. Inspect pistons for cracks, scoring, scuffing, overheating, or abnormal combustion. Check for piston corrosion indicating coolant leakage. Measure ring side clearance and piston-to-bore clearance. Resize pistons if needed. Inspect connecting rods for cracks or damage, replace if necessary.

Prior to removing the piston and connecting rod assemblies, the cylinder head(s), oil pan, and oil pump (except for 3.8L V6 models) must be removed. 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 special tool, following the manufacturer's instructions, as failure to do so may result in piston breakage. After removing the cylinder ridges, turn the engine upside-down with the crankshaft facing up. Before removing the connecting rods, check the endplay with feeler gauges, ensuring that the play is removed between the first connecting rod and the crankshaft throw; if the endplay exceeds the service limit, new connecting rods will be necessary, and if new rods or a new crankshaft are installed, the endplay may need to be adjusted. 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 by 1/2-turn until they can be removed by hand, then take off the number one connecting rod cap and bearing insert without dropping the bearing 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 that all ridges have been removed from the cylinder. Repeat this process for the remaining cylinders. After removal, reassemble the connecting rod caps and bearing inserts in their respective connecting rods and install the cap nuts finger tight, leaving the old bearing inserts in place until reassembly to prevent accidental damage to the connecting rod bearing surfaces. Avoid separating the pistons from the connecting rods.

Prior to inserting the piston and connecting rod combination then the cylinder walls should be smooth, top edge of each cylinder relieved and the crankshaft fitted. Take off the cap from number one connecting rod and note the marks that were made while taking off then clean the bearing surfaces of the con rod with a clean lint free cloth. Remove the new upper bearing insert from its container and wash the back side then fit it into the connecting rod with the tab side, do not hammer the tab into the recess. Do the same for the other bearing insert of the rod cap , and ensure that all the mating surfaces are clean and free from oil. Place the gaps of the piston ring to the piston, put a hose over each connecting rod cap bolt, and then apply some drops of clean engine oil to the piston and the rings, and then place a piston ring compressor placing the skirt out so as to direct the piston onto the cylinder. Bore the number one connecting rod journal down to the bottom dead center and lubricate the cylinder walls with engine oil. Place the piston/connecting rod assembly into the cylinder bore so that the arrow, or notches, on the piston face points toward the front of the engine and gently hit the top of the ring compressor so that it makes contact with the block. Gently strike the piston with the wooden end of a hammer to help guide the connecting rod onto the crankshaft journal without a force that will harm the piston or the rings. Again, using Plastigage, it is recommended to check the connecting rod-bearing oil clearance after the installation provided that the bearing faces are clean, a uniform layer of grease or assembly lube is applied and by tightening the nuts to the prescribed torque, the rod cap is reinstalled. The same process follows for the rest of the assembly in which the bearing inserts and the connecting rods should be clean, the piston/rod assembly should be correct and the cylinder walls and bearing faces should be lubricated. After final installation of the last assembly, rotate the crankshaft and feel for binding, and then, check the connecting rod end play and if it correct as well as need to check the connecting rod end play especially if new components are installed.