Why does the exhaust not line up with timing chain Marks?
Why does the exhaust not line up with timing chain Marks?
The confusion is that the exhaust cam seems way far clockwise and also doesn’t line up with the timing chain marks. Not to mention, the car has never thrown codes and performance is unaffected (155mph on the Autobahnen). I didn’t know that there was this much tolerance before interference.
How to calculate the duration of intake valve timing event?
To calculate the duration of any intake valve timing event, add 180° to the intake opening and closing time. For example, if an intake valve opens at 12° before top dead center (BTDC) and closes at 40° after bottom dead center (ABDC), the duration of the valve timing event is 232°. Exhaust timing follows a similar calculation.
How often do timing marks have to line up?
They only have to line up with your timing it at DTC. That’s normal. The marks line up about every 20 to 30 rotations. Put the new chain on and line ’em up. Then turn it over twice to be sure you’re OK and they won’t be lined up. It’s OK. They only have to line up with your timing it at DTC.
How to calculate the intake and exhaust centerlines?
From this you can calculate the intake and exhaust centerlines. To find the intake lobe centerline, divide the intake duration by two and subtract the indicated intake opening point as shown in our example with the Comp XE274 example. Sometimes you find a very mild or stock cam where the IO occurs after TDC (ATDC).
The confusion is that the exhaust cam seems way far clockwise and also doesn’t line up with the timing chain marks. Not to mention, the car has never thrown codes and performance is unaffected (155mph on the Autobahnen). I didn’t know that there was this much tolerance before interference.
How to line up timing marks, no belt on?
Very good writeup, but just one clarification. On #6, rotate the engine and check the crank and cam pully marks for correct alignment. The belt marks will take many revolutions to all line up exactly as you installed the belt. A couple of rotations is all that is required to know you have it right.
Is it normal for the timing marks to be off?
I’m shocked thst the cam would be out of phase and in this direction, no less. That’s normal. The marks line up about every 20 to 30 rotations. Put the new chain on and line ’em up. Then turn it over twice to be sure you’re OK and they won’t be lined up. It’s OK. They only have to line up with your timing it at DTC. Correct correct.
How are the timing marks on a Toyota Tundra determined?
The camshafts position, relative to crankshaft position, determines whether or not the pistons are on their intake, compression, power, or exhaust strokes.Since each piston reaches it’s own TDC once per crankshaft revolution, 1 piston out of 8 is at TDC for every 45 degrees of crankshaft rotation.
