Determining top dead center
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If the engine is a short block on the stand, you can determine TDC with a simple homemade piston stop made from a strap of metal bolted across two head bolt holes, with the strap drilled and tapped for an adjustable bolt/nut assembly. A dial indicator can also be used on a fixture that bridges the bore or on a magnetic base. This would be an ideal time to note the piston-to-deck clearance for use in computing the static compression ratio and quench distance. | If the engine is a short block on the stand, you can determine TDC with a simple homemade piston stop made from a strap of metal bolted across two head bolt holes, with the strap drilled and tapped for an adjustable bolt/nut assembly. A dial indicator can also be used on a fixture that bridges the bore or on a magnetic base. This would be an ideal time to note the piston-to-deck clearance for use in computing the static compression ratio and quench distance. | ||
| − | If the engine | + | If the engine has the heads on, use a spark plug-type piston stop tool. If there is a timing tab present, use it to mark the position with. If no tab, use a length of stiff wire that's attached to the engine to use to show the positions. This may be made easier by using a degree wheel or a timing tape on the outer ring of the damper. |
| + | #Set the plug hole-mounted piston stop to contact the piston close to TDC | ||
| + | #Rotate engine until the stop just contacts the piston- mark the location | ||
| + | #Then rotate in the opposite direction until the piston is stopped | ||
| + | #Half way between the two marks is approximately TDC | ||
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[[File:TDC1.jpg |thumb|left|Strap-type and spark plug-type piston stop tools]] | [[File:TDC1.jpg |thumb|left|Strap-type and spark plug-type piston stop tools]] | ||
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