Genuine Pontiac Fiero Piston

Pontiac Fiero Piston Parts Questions & Experts Answers

• Piston & Piston Pinion Assembly, (Std)
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  Q: What steps must be taken to prepare piston/connecting rod assemblies for inspection on Pontiac Fiero?

  A: However, before the inspection process can be conducted the piston/connecting rod assemblies have to be cleaned and the original Piston Rings have to be taken off the piston, new piston rings should be fitted during the assembling process. There should be use of a piston ring installation tool while removing the rings so as not to cause damage on the pistons. Finally, every speck of carbon must be removed from the crown of the piston with a hand-held wire brush or fine emery cloth; wire brush operated with a motor drill is to be avoided because the material of the piston is very soft. There should be a piston ring groove cleaning tool which cleans the carbon deposits on the grooves A piece of an old ring can be used if the groove cleaning tool is not available but it has to be done cautiously so as not to manufacture grooves on the surface. After surface cleaning the piston/rod assemblies should be dried appropriately and then examined to ascertain if the oil return holes are open. In the case that the pistons are not worn out or damaged in such a way that they cannot be restored through hone and sizing then new pistons will not be needed. Every piston should be checked for crack or score or scuff or hole or burnt area as such defects show that the engine might have overheated or combusted abnormally and the cooling system as well as the lubrication system should then be checked. Some signs of rusting were observed predominantly as pits and therefore may have been attributed to leakage of the coolant into the combustion chamber which will need to be fixed in future to avoid such occurrences. The piston ring side clearance should be gauged using a feeler gauge, the measurement should be taken at four points around the groove and in the case that the clearance is beyond what is allowed, then new pistons will be needed. The bore and piston diameter have to also be measured to check the piston-to-bore clearance to ensure that they are matched; if there is excessive clearance then rebore and new pistons are required. Rocker / piston-to-rod clearance are to be determined by rotating one part in one (piston) direction and the other (rod) in the opposite direction; the end play felt is the clearance, and should show a significant amount of play to warrant adjustment. If pistons have to be replaced because of worn out or damaged ones or if the pins are loose, then they should be taken to an automotive mechanics for renewal or reconditioning of connecting rods should also be taken for rectification of such flaws as bentness. Last but not the least, the connecting rods must also be checked for any signs of cracks and damages; the old bearing inserts have to be removed and cleaned thoroughly but for this purpose, they can be temporarily unbolted and taken out.