Determining top dead center
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VERIFYING TOP DEAD CENTER AT THE DAMPER/POINTER WITH THE ENGINE ASSEMBLED. | VERIFYING TOP DEAD CENTER AT THE DAMPER/POINTER WITH THE ENGINE ASSEMBLED. | ||
| − | First off, the large round hub | + | First off, the large round hub attached to the front of the crankshaft is called a harmonic damper by some and a harmonic balancer or simply "balancer" OR "damper" by others. |
| − | If it is bolted to the | + | If it is bolted to the crankshaft of an engine that is internally balanced, then it serves only the function of being a harmonic damper, dampening vibrations set up in the crankshaft as a result of the rod journal springing back and forth from the forces applied to it during operation. |
| − | If it is bolted to the | + | If it is bolted to the crankshaft of an engine that is externally balanced, then it serves the dual purpose of damper and balancer. |
Unless the engine has been unaltered and is "as built" by the manufacturer, you have no idea if the TDC notch on the ring matches the timing pointer attached to the block or front cover, even if the outer ring has not slipped at all. | Unless the engine has been unaltered and is "as built" by the manufacturer, you have no idea if the TDC notch on the ring matches the timing pointer attached to the block or front cover, even if the outer ring has not slipped at all. | ||
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In this exercise, you will install a piston stop tool into #1 spark plug hole (driver's side front on a Chevy/MOPAR, passenger's side front on a Ford). If you use the damper/balancer retaining bolt to turn the crank and turn the crank counter-clockwise, you risk loosening the bolt in the crank that retains the harmonic damper. Then you have to get your buddy to crawl under and hold a large flat-blade screwdriver into the flexplate/flywheel ring gear teeth and jam it against the bellhousing to keep the engine from turning while you tighten the bolt back (60 ft/lbs on a SBC, 85 ft/lbs on a BBC). | In this exercise, you will install a piston stop tool into #1 spark plug hole (driver's side front on a Chevy/MOPAR, passenger's side front on a Ford). If you use the damper/balancer retaining bolt to turn the crank and turn the crank counter-clockwise, you risk loosening the bolt in the crank that retains the harmonic damper. Then you have to get your buddy to crawl under and hold a large flat-blade screwdriver into the flexplate/flywheel ring gear teeth and jam it against the bellhousing to keep the engine from turning while you tighten the bolt back (60 ft/lbs on a SBC, 85 ft/lbs on a BBC). | ||
| − | Another risk is in stripping the threads or breaking the bolt off if you use the damper bolt to turn the engine over. If you feel resistance, or if the bolt tightens more as you attempt to turn the | + | Another risk is in stripping the threads or breaking the bolt off if you use the damper bolt to turn the engine over. If you feel resistance, or if the bolt tightens more as you attempt to turn the crankshaft- you will need to use a remote starter switch or turn the damper by hand (plugs out) or turn the flexplate/flywheel from beneath the vehicle. |
Far better to just turn the crank clockwise only (keeping the bolt tight) and sidestep a problem before it occurs. Been there, done that. The following tool also solves this problem. Remove the crank pulley and bolt it onto the damper/balancer ............. | Far better to just turn the crank clockwise only (keeping the bolt tight) and sidestep a problem before it occurs. Been there, done that. The following tool also solves this problem. Remove the crank pulley and bolt it onto the damper/balancer ............. | ||
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