REMOVAL & INSTALLATION
See Figures 1, 2, 3, 4, 5, 6, 7 and 86 Cylinder Engine
- Disconnect the negative battery cable.
- Drain the cooling system and the crankcase oil.
- Remove the cylinder head.
- Remove the oil pan, the oil pump inlet tube and the oil pump.
- Turn the crankshaft until the piston to be removed is at the bottom of its travel and place a cloth on the piston head to collect any filings. Using a ridge reaming tool, remove any ridge of carbon or any other deposit from the upper cylinder walls where piston travel ends. Do not cut into the piston ring travel area more than 1 / 32 in. (0.8mm) while removing the ridge.
- Mark all of the connecting rod caps so that they can be reinstalled in the original positions from which they are removed and remove the connecting rod bearing cap. Also identify the piston assemblies as they, too, must be reinstalled in the same cylinder from which removed.
- With the bearing caps removed, the connecting rod bearing bolts are potentially damaging to the cylinder walls during removal. To guard against cylinder wall damage, install 4 in. (101mm) or 5 in. (127mm) lengths of 3 / 8 in. (9.5mm) rubber tubing onto the connecting rod bolts. These will also protect the crankshaft journal from scratches when the connecting rod is installed, and will serve as a guide for the rod.
- Squirt some clean engine oil into each cylinder before removing the pistons. Using a wooden hammer handle, push the connecting rod and piston assembly out of the top of the cylinder (pushing from the bottom of the rod). Be careful to avoid damaging both the crank journal and the cylinder wall when removing the rod and piston assembly.
- Before installing the piston/connecting rod assembly, be sure to clean all gasket mating surfaces, oil the pistons, piston rings and the cylinder walls with light engine oil.
- Be sure to install the pistons in the cylinders from which they were removed. The connecting rod and bearing caps are numbered from 1 to 6 beginning at the front of the engine. The numbers on the connecting rod and bearing cap must be on the same side when installed in the cylinder bore. If a connecting rod is ever transposed from one engine or cylinder to another, new bearings should be fitted and the connecting rod should be numbered to correspond with the new cylinder number. The notch on the piston head goes toward the front of the engine.
- Make sure the ring gaps are properly spaced around the circumference of the piston. Make sure rubber hose lengths are fitted to the rod bolts. Fit a piston ring compressor around the piston and slide the piston and connecting rod assembly down into the cylinder bore, pushing it in with the wooden hammer handle. Push the piston down until it is only slightly below the top of the cylinder bore. Guide the connecting rods onto the crankshaft bearing journals carefully, using the rubber hose lengths, to avoid damaging the crankshaft.
- Check the bearing clearance of all the rod bearings, fitting them to the crankshaft bearing journals.
- After the bearings have been fitted, apply a light coating of engine oil to the journals and bearings.
- Turn the crankshaft until the appropriate bearing journal is at the bottom of its stroke, then push the piston assembly all the way down until the connecting rod bearing seats on the crankshaft journal. Be careful not to allow the bearing cap screws to strike the crankshaft bearing journals and damage them.
- After the piston and connecting rod assemblies have been installed, check the connecting rod side clearance on each crankshaft journal.
- Prime and install the oil pump and the oil pump intake tube, then install the oil pan.
- Reassemble the rest of the engine in the reverse order of disassembly.
- Disconnect the negative battery cable.
- Drain the cooling system and the crankcase oil.
- Remove the intake manifold.
- Remove the cylinder heads.
- Remove the oil pan.
- Remove the oil pump.
- Turn the crankshaft until the piston to be removed is at the bottom of its travel, then place a cloth on the piston head to collect filings.
- Remove any ridge of deposits at the end of the piston travel from the upper cylinder bore, using a ridge reaming tool. Do not cut into the piston ring travel area more than 1 / 32 in. (0.8mm) when removing the ridge.
- Make sure that all of the connecting rod bearing caps can be identified, so they will be reinstalled in their original positions.
- Turn the crankshaft until the connecting rod that is to be removed is at the bottom of its stroke and remove the connecting rod nuts and bearing cap.
- With the bearing caps removed, the connecting rod bearing bolts are potentially damaging to the cylinder walls during removal. To guard against cylinder wall damage, install 4-5 in. (102-127mm) lengths of 3 / 8 in. (0.8mm) rubber tubing onto the connecting rod bolts. These will also protect the crankshaft journal from scratches when the connecting rod is installed, and will serve as a guide for the rod.
- Squirt some clean engine oil into each cylinder before removing the piston assemblies. Using a wooden hammer handle, push the connecting rod and piston assembly out of the top of the cylinder (pushing from the bottom of the rod). Be careful to avoid damaging both the crank journal and the cylinder wall when removing the rod and piston assembly.
- Remove the bearing inserts from the connecting rod and cap if the bearings are to be replace, and place the cap onto the piston/rod assembly from which it was removed.
- Install the piston/rod assemblies in the same manner as that for the 6 cylinder engine. See the previous procedure for details.
- The connecting rod and bearing caps are numbered from 1 to 4 in the right bank and from 5 to 8 in in the left bank, beginning at the front of the engine. The numbers on the rod and cap must be on the same side when they are installed in the cylinder bore. Also, the largest chamfer at the bearing end of the rod should be positioned toward the crank pin thrust face of the crankshaft and the notch in the head of the piston faces toward the front of the engine.
- See the appropriate component procedures in this section to assemble the engine.
See Figures 9 and 10
All of the Ford engines covered in this guide utilize pressed-in wrist pins, which can only be removed by an arbor press. The piston/connecting rod assemblies should be taken to an engine specialist or qualified machinist for wrist pin removal and installation.
A piston ring expander is necessary for removing the piston rings without damaging them; any other method will result in the rings being bent, scratched or distorted, or the piston itself being damaged. When the rings are removed, clean the ring grooves using an appropriate ring groove cleaning tool, using care not to cut too deeply. Thoroughly clean all carbon and varnish from the piston with solvent.
Inspect the pistons for scuffing, scoring, cracks, pitting, or excessive ring groove wear. If these are evident, the piston must be replaced.
The piston should also be checked in relation to the cylinder diameter. Using a telescoping gauge and micrometer, or dial gauge, measure the cylinder bore diameter perpendicular (90°) to the piston pin, 2 1 / 2 in. (63.5mm) below the cylinder block deck (surface where the block mates with the heads). Then, with the micrometer, measure the piston, perpendicular to its wrist pin on the skirt. The difference between the two measurements is the piston clearance. If the clearance is within specification or slightly below (after the cylinders have been bored or hones), finish honing is all that is necessary. If the clearance is excessive, try to obtain a slightly larger piston to bring clearance to within specifications. If this is not possible, obtain the first oversize piston and hone (or if necessary, bore) the cylinder to size. Generally, if the cylinder bore is tapered 0.005 in. (0.127mm) or more, or is out-of-round 0.003 in. (0.076mm) or more, it is advisable to rebore for the smallest possible oversize piston and rings.
After measuring, mark the pistons with a felt tip pen for reference when assembling.
Cylinder honing and/or boring should be performed by a reputable, professional mechanic with the proper equipment. In some cases, clean-up honing can be done with the cylinder block in the car, but most excessive honing and all cylinder boring must be done with the block stripped and removed from the vehicle.Measuring Pistons
See Figures 11 and 12
Check used piston-to-cylinder bore clearance as follows:
- Measure the cylinder bore diameter with a telescope gauge.
- Measure the piston diameter. When measuring the pistons for size or taper, measurements must be made with the piston pin removed.
- Subtract the piston diameter from the cylinder bore diameter to determine piston-to-bore clearance.
- Compare the piston-to-bore clearances obtained with those clearances recommended in the chart. Determine if the piston-to-bore clearance is in the acceptable range.
- When measuring taper, the largest reading must be at the bottom of the skirt.
- If the used piston is not acceptable, check the service piston size and determine if a new piston can be selected. Service pistons are available in standard, high limit and standard oversize.
- If the cylinder bore must be reconditioned, measure the new piston diameter, then hone the cylinder bore to obtain the preferred clearance.
- Mark the piston to identify the cylinder for which it was fitted.
See Figure 13
- When cylinders are being honed, follow the manufacturer's recommendations for the use of the hone.
- Occasionally, during the honing operation, the cylinder bore should be thoroughly cleaned and the selected piston checked for correct fit.
- When finish-honing a cylinder bore, the hone should be moved up and down at a sufficient speed to obtain a very fine uniform surface finish in a cross-hatch pattern of approximately 45-65° included angle. The finish marks should be clean but not sharp, free from imbedded particles and torn or folded metal.
- Permanently mark the piston for the cylinder to which it has been fitted and proceed to hone the remaining cylinders.
Thoroughly clean the bores with hot water and detergent. Scrub well with a stiff bristle brush and rinse thoroughly with hot water. It is extremely essential that a good cleaning operation be performed. If any of the abrasive material is allowed to remain in the cylinder bores, it will rapidly wear the new rings and cylinder bores. The bores should be swabbed several times with light engine oil and a clean cloth and then wiped with a clean dry cloth. CYLINDERS SHOULD NOT BE CLEANED WITH KEROSENE OR GASOLINE! Clean the remainder of the cylinder block to remove the excess material spread during the honing operation.Piston Ring End-Gap
See Figure 14
Piston ring end-gap should be checked while the rings are removed from the pistons. Incorrect end-gap indicates that the wrong size rings are being used; ring breakage could occur.
Compress the piston rings to be used in a cylinder, one at a time, into that cylinder. Squirt clean oil into the cylinder, so that the rings and the top 2 in. (51mm) of cylinder wall are coated. Using an inverted piston, press the rings approximately 1 in. (25mm) below the deck of the block. Measure the ring end-gap with the feeler gauge, and compare to the ring gap specification in this section. Carefully pull the ring out of the cylinder and file the ends squarely with a fine file to obtain the proper clearance.
See Figure 15
Check the pistons to see that the ring grooves and oil return holes have been properly cleaned. Slide a piston ring into its groove, and check the side clearance with a feeler gauge. Make sure you insert the gauge between the ring and its lower land (lower edge of the groove), because any wear that occurs forms a step at the inner portion of the lower land. If the piston grooves have worn to the extend that relatively high steps exist on the lower land, the piston should be replaced, because these will interfere with the operation of the new rings and ring clearance will be excessive. Piston rings are not furnished in oversize widths to compensate for ring groove wear.
Install the rings on the piston, lowest ring first, using a piston ring expander. There is a high risk of breaking or distorting the rings, or scratching the piston, if the rings are installed by hand or other means.
Position the rings on the piston. Spacing of the various piston ring gaps is crucial to proper oil retention and even cylinder wear. When installing new rings, refer to the installation diagram furnished with the new parts.