Timeline for 4 stroke valve timing diagram: if valves are open during TDC, wouldn't they hit the piston?
Current License: CC BY-SA 3.0
8 events
| when toggle format | what | by | license | comment | |
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| Jul 26, 2017 at 13:19 | comment | added | Mauro | @Danny - additionally some engines have variable valve timing which can open and close valves earlier based on a number of mechanism (variators, double cam profiles, hydraulic valves) in all cases they are still synchronised to the crankshaft | |
| Jul 26, 2017 at 13:13 | comment | added | Mauro | @Danny - This image on wikipedia shows an animation of how valves open and close in relation to a pistons movement | |
| Jul 26, 2017 at 11:50 | comment | added | Danny | So if both valves are closed in piston is all the way to the top that is top dead centerCorrect | |
| Jul 7, 2014 at 2:03 | comment | added | Bob Cross♦ | @midnightBlue, you are right: the engine has to be perfectly calibrated in an interference engine. Otherwise, there could be contact between piston and valve (which is, as you might imagine, bad). | |
| Jul 7, 2014 at 1:37 | comment | added | Pᴀᴜʟsᴛᴇʀ2♦ | @midnightBlue ... Please see edits. Believe me when I say, it's a complicated mess, it is. Also, make sure you read the last sentence, it is very true. | |
| Jul 7, 2014 at 1:34 | history | edited | Pᴀᴜʟsᴛᴇʀ2♦ | CC BY-SA 3.0 |
added 331 characters in body
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| Jul 6, 2014 at 20:55 | comment | added | midnightBlue | I still am not sure I fully understand. Even if the valve takes time to open and close, say in my example the intake valve that begins to opens at 12 degrees before TDC, the intake valve would be somewhat open when it reaches TDC no? Or is it perfectly calibrated that when it is actually open fully, the piston is beyond the TDC point so as not to hit the valve? | |
| Jul 6, 2014 at 15:03 | history | answered | Pᴀᴜʟsᴛᴇʀ2♦ | CC BY-SA 3.0 |
