Determining top dead center
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There are a multitude of different dampers and timing pointer locations on a small block Chevy. Refer to [[Timing Tabs and Damper TDC Lines SBC]] for more on them. Other engines can refer to a service manual. | There are a multitude of different dampers and timing pointer locations on a small block Chevy. Refer to [[Timing Tabs and Damper TDC Lines SBC]] for more on them. Other engines can refer to a service manual. | ||
| − | The whole reason for doing this operation in the first place is to be able to time the engine with a timing light and know '''''absolutely''''' that the timing is correct. The elastomeric material that connects the outer inertia ring of the harmonic damper/balancer to the inner hub of the damper/balancer which presses onto the snout of the crankshaft begins to break down over time due to ozone in the atmosphere and oil and fuel or other foreign materials which may find their way onto the material. | + | The whole reason for doing this operation in the first place is to be able to time the engine with a timing light and know '''''absolutely''''' that the timing is correct. The elastomeric material that connects the outer inertia ring of the harmonic damper/balancer to the inner hub of the damper/balancer which presses onto the snout of the crankshaft begins to break down over time due to ozone in the atmosphere and oil and fuel or other foreign materials which may find their way onto the material. When this happens, the outer ring may slip circumferentially in relation to the inner hub, rendering any attempt to time the engine with a timing light futile. Even though this operation you are about to do will bring the timing marks back to correct for the time being, there is no guarantee that the ring will not slip further after a while. You also have no idea if the timing pointer matched the inertia ring in the first place if the engine has been disassembled and reassembled by someone else in its lifetime. If you want to bulletproof the operation, then start with a new or rebuilt damper and use the correct timing pointer for that damper. |
| − | + | ===Checking the outer damper ring for movement=== | |
| + | [[File:Damper line.jpg|left|400px]]Draw a sharpie line as shown in the image below. When the timing light is pointed at the TDC line, the sharpie line will also be seen. By revving the engine and running it at different speeds, if the outer ring is loose, the line on the outer ring will be seen to move independently of the line on the inner hub. | ||
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| − | + | ==Rebuilt dampers== | |
| + | One noted place to buy a rebuilt damper/balancer is [http://www.damperdoctor.com/ Damper Doctor]. They disassemble stock, OEM production dampers, clock the hub to the ring and reassemble the unit with new elastomeric material pressed together under tremendous hydraulic pressure. An 8" damper for a 350 Chevy can be had for a mere $32.95 (ca. 2012), deal of the century!!!! | ||
| − | The option is a used damper/balancer that may be clocked worse than the one you have or an aftermarket damper/balancer that will cost more money and may not have been correctly machined on the inner hub diameter. Some of these | + | The option is a used damper/balancer that may be clocked worse than the one you have or an aftermarket damper/balancer that will cost more money and may not have been correctly machined on the inner hub diameter. Some of these Chinese dampers being sold are either oversize or undersize for the production crank snout diameter. The damper/balancer MUST BE A SNUG PRESS-FIT on the crank in order to properly transfer harmonics from the crankshaft to the damper/balancer hub. |
On a street engine or a drag race engine down to 11.00 E.T. in the quarter mile, an OEM-type damper/balancer may be used legally. At 10.99 E.T., an aftermarket SFI-18.1 damper/balancer is required. | On a street engine or a drag race engine down to 11.00 E.T. in the quarter mile, an OEM-type damper/balancer may be used legally. At 10.99 E.T., an aftermarket SFI-18.1 damper/balancer is required. | ||
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==Resources== | ==Resources== | ||
| − | ;Crankshaft Coalition Wiki articles | + | ;Crankshaft Coalition Wiki articles'''<nowiki>:</nowiki>''' |
| − | :*[http://www.crankshaftcoalition.com/wiki/Adjusting_hydraulic_lifters Adjusting hydraulic lifters] | + | *[http://www.crankshaftcoalition.com/wiki/Adjusting_hydraulic_lifters Adjusting hydraulic lifters] |
| − | + | *[http://www.crankshaftcoalition.com/wiki/Valve_train_points_to_check Valve train points to check] | |
| − | + | *[[How to install a distributor]] | |
| + | *[[Timing Tabs and Damper TDC Lines SBC]] | ||
| + | *[[How To Make A Timing Tape]] | ||
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[[Category:Engine]] | [[Category:Engine]] | ||
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