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techtalk:ref:tools135 [2018/05/29 04:05] – [For Finding Piston Top Dead Center (TDC)] hippysmacktechtalk:ref:tools135 [2024/01/24 03:45] (current) – hippysmack
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 ====== REF: Tools - 135 ====== ====== REF: Tools - 135 ======
 ====== For Finding Piston Top Dead Center (TDC) ====== ====== For Finding Piston Top Dead Center (TDC) ======
-  * 1986-2003 stock flywheels up until 2004 have their own TDC marks. [[techtalk:evo:engctl01#ignition_timing_-_all_models_thru_2003|Refer to this article regarding which symbol represents TDC on them]].  +See related procedures for [[techtalk:ref:svcproc22#reftroubleshooting_-_engine_-_05|Finding TDC of the Piston]] in the REF section of the Sportsterpedia. 
-  * 2004 and later (or 03 and prior engines with 04 and later Sportster / Buell crankshaft upgrades) will not have a TDC mark on the flywheel. + 
 ===== With the Head On: ===== ===== With the Head On: =====
  
 ==== Using a Straw ==== ==== Using a Straw ====
 +This is not accurate enough to find True TDC. \\ 
 +However, true TDC is not always necessary to find depending on circumstance. \\
 +You can use a straw through the spark plug hole to measure when the piston is close to TDC with the rocker box on or off. \\
 +The straw is soft enough that you won't risk breaking anything if it gets squished between the piston and the head / valves. \\ 
 +See procedure and cautions for [[techtalk:ref:svcproc22#find_tdc_using_a_straw|Finding TDC with a straw]] in the REF section of the Sportsterpedia.
  
 +|A straw in plug hole for finding TDC ((photo by Hippysmack))| 
 +|{{techtalk:ref:tools:tdc_with_straw_-_single_or_dual_plug_heads_by_hippysmack.jpg?direct&300|}}|
  
-  * You can use a straw through the spark plug hole to measure when the piston is close to TDC with the rocker box on or off. When done, it can only be regarded as an approximate setting however. The piston is only at TDC once for a very short length of time until the rod rolls back over to the down-stroke.  It is difficult if near impossible to set exact TDC with a straw. But, unless you are creating a new timing mark or finely setting cam or ignition timing, this is an easy way to accomplish TDC. +==== Using a Piston Stop and Degree Wheel ==== 
-  * The straw is soft enough that you won't risk breaking anything if it gets squished between the piston and the head. +See procedure and cautions for [[techtalk:ref:svcproc22#find_true_tdc_using_a_piston_stop_and_a_degree_wheel|Finding TDC with a Piston Stop and a Degree Wheel]] in the REF section of the Sportsterpedia. \\
-  * For best results, hold the straw loosely while picking up on it periodically to keep it from getting stuck (which will affect your measurements).  +
-  * Using a straw with the engine assembled: +
-    * This is best handled with the bike on a lift (or at least the rear tire off the ground) and the transmission in the highest gear while rotating the rear tire in the forward direction. +
-  * Using a straw with the primary and / or gearcase cover(s) off: +
-    * The rear tire doesn't have to be lifted as you can put the transmission in neutral and turn the engine over with the shaft nut on either side. +
-  * It's also best done with two people (one turning the rear tire and one manning the straw). However, it can be done by one person watching the straw rise with the piston and then switching to one hand on the straw and the other nudging the rear tire to feel when the straw goes down. +
-  * **Caution**: Turning the rear tire while the transmission is engaged will produce up and down movement of the entire bike, make sure it is tied down and secured before attempting to rotate the tire.+
  
-|Straw in plug hole for single or dual plug heads ((photo by Hippysmack))|Alternative location with dual plug heads \\ (better location, less binding of the straw). ((photo by Hippysmack))| +|Engine calibration and set-up kit: Includes a piston stop, gauge extender, adapters and a TDC whistle. (piston stop shown installed) ((photos by rocketmangb of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-engine-conversions/172487-tools?t=1846392))||| 
-|{{techtalk:ref:tools:tdc_with_straw_-_single_or_dual_plug_heads_by_hippysmack.jpg?direct&300|}}|{{techtalk:ref:tools:tdc_with_straw_1_by_hippysmack.jpg?direct&300|}}|+|{{:techtalk:ref:tools:engine_calibration_and_setup_kit_1_by_rocketmangb.jpg?direct&300|}}|{{:techtalk:ref:tools:engine_calibration_and_setup_kit_2_by_rocketmangb.jpg?direct&300|}}|{{:techtalk:ref:tools:engine_calibration_and_setup_kit_3_by_rocketmangb.jpg?direct&300|}}| 
 + 
 +==== Using a TDC Whistle ==== 
 + 
 +Basically, you install whistle in the spark plug hole, rotate the engine and wait for the whistle to blow. \\  
 +There is a distinct difference in the sound of the whistle between the 2 TDCs from your finger. \\  
 +Just like the finger method above, a TDC whistle only works when disassembling. \\ 
 +(or rather only works if the pushrods are installed) \\ 
 +It doesn't work when assembling. \\ 
 +Every up stroke has compression when assembling and the valvetrain isn't hooked up and working. \\ 
 +See procedure for [[techtalk:ref:svcproc22#find_compression_using_a_tdc_whistle|Finding compression with a TDC whistle]] in the REF section of the Sportsterpedia. \\ 
 + 
 +|  14 mm and 12 mm TDC whistles ((photo by Hippysmack))  |  12 mm TDC whistle ((photo by Hippysmack))  | 
 +|{{:techtalk:ref:tools:tdc_whistles_by_hippysmack.jpg?direct&300|}}|{{:techtalk:ref:tools:tdc_whistle_2_by_hippysmack.jpg?direct&300|}}|
  
 ===== With the Head Off ===== ===== With the Head Off =====
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 |{{techtalk:ref:tools:dial_depth_gauge_3_by_hippysmack.jpg?direct&300|}}|{{techtalk:ref:tools:dial_depth_gauge_4_by_hippysmack.jpg?direct&300|}}|{{techtalk:ref:tools:dial_depth_gauge_5_by_hippysmack.jpg?direct&300|}}| |{{techtalk:ref:tools:dial_depth_gauge_3_by_hippysmack.jpg?direct&300|}}|{{techtalk:ref:tools:dial_depth_gauge_4_by_hippysmack.jpg?direct&300|}}|{{techtalk:ref:tools:dial_depth_gauge_5_by_hippysmack.jpg?direct&300|}}|
 |:::|Double check the reading before proceeding|Double check the reading before proceeding|  |:::|Double check the reading before proceeding|Double check the reading before proceeding| 
 +
 +====== Spark Plug Hole Adapters ======
 +**For Dial Indicators and Piston Stops**: \\
 +
 +You can break the ceramic out of a spare spark plug and drill / tap the side walls for screws. \\ 
 +Then insert a 1" dial indicator in the middle of the plug. \\
 +The indicator is a slip fit in the middle of the hole and then snug the screw up against it to lock it in place. ((Ranchero50 of the XLFORUM https://www.xlforum.net/forum/sportster-motorcycle-forum/sportster-motorcycle-motor-engine/sportster-motorcycle-engine-conversions/172487-tools?t=1846392)) \\
  
 \\ \\

Trace: • IH: Engine Mechanicals - Sub-01A