Estimating timing chain wear
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(→Checking for "jumped timing": add text, link, minor clean up) |
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==Checking for "jumped timing"== | ==Checking for "jumped timing"== | ||
To check for jumped timing: | To check for jumped timing: | ||
| − | + | *If the distributor was moved, put it back to where it was when the engine was running correctly. | |
| − | + | *Take the plugs out so the engine is easy to turn over by using a socket on the damper bolt. | |
| − | + | *Bring the line on the damper to TDC on the timing tab. | |
| − | + | *Remove the distributor cap and note where the rotor is pointing- on a V8 it should be close to either #1 or #6. If it isn't, the timing has jumped, providing the timing marks are correct. | |
| + | |||
| + | In cases where the timing has been disturbed or the engine has not run yet and it's suspected the cam phasing to be wrong, the following method from Comp Cams can be used to degree the cam. This will show if there's any error in the way the cam was ground, or a problem w/the timing set: | ||
| + | |||
| + | ===Camshaft degreeing instructions=== | ||
| + | The reason for degreeing a camshaft is to check that it is phased correctly to the crank. Some things that may cause the cam to be out of phase are: | ||
| + | * Cam or crank gear marked incorrectly | ||
| + | * Incorrectly machined keyways. | ||
| + | * Misaligned cam gear dowel pin/bolt holes. | ||
| + | * Improper machining of camshaft. | ||
| + | * Accumulation of machining tolerances | ||
| + | |||
| + | ====Equipment needed:==== | ||
| + | * Degree wheel, or at least a [http://www.crankshaftcoalition.com/wiki/How_to_make_a_timing_tape '''timing tape'''] on the damper | ||
| + | * A stiff wire pointer attached to the block. A coat hangar or welding/brazing rod will work. | ||
| + | * Dial indicator with enough range to measure full cam lift | ||
| + | * Magnetic or attachable base to affix the dial indicator | ||
| + | * [http://www.crankshaftcoalition.com/wiki/Determining_top_dead_center Top Dead Center] (TDC) stop. | ||
| + | * Solid lifter to fit the engine, or a hydraulic lifter made solid by stacking washers in it or filling with grease. | ||
| + | |||
| + | ====Intake centerline method==== | ||
| + | This method of cam degreeing is not he only way to degree a cam, nor is it considered to be the most accurate. But in this case and for this application it is plenty accurate enough and is quicker, too. | ||
| + | |||
| + | All that is required is finding TDC, then turning the crank in the normal direction of rotation until reaching the point where #1 intake valve is at its maximum lift. | ||
| + | |||
| + | [[Media:Degreeing instructions.pdf|'''Degreeing instructions here''']], about 2/3 down the page. | ||
==Timing set types== | ==Timing set types== | ||
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