Timing and TDC... type 4 confusion
-
fredc125
- Posts: 41
- Joined: Tue Jul 18, 2017 3:14 am
Timing and TDC... type 4 confusion
After many hours of research I'm still not finding the answers I need so I'll ask them here. Yes I'm a newbie. I need to figure out the timing on my type 4 2.0 ltr. and more specifically the "0" degrees TDC position of the crank. I have two questions: 1) My fan pulley has only one mark on it, a big notch on the back side of the pulley rim. Would this be at 0 degrees TDC or is it offset to some predesignated number of degrees like say 28 degrees BTDC or 7.5 or 10 ? 2) I've read that aligning the pulley mark with the split in the case will find TDC but now I have a scale on the motor with a "0" on it indicating TDC and this is not lined up with the split of the case. I assume the scale is showing me TDC but can't ignore the fact that there might be another trick secret that only VW folks seem to know that makes all my assumptions null and void. Is "0" on the scale TDC ? I've read that I can find #1 TDC by watching the valves but when both valves close on the compression stroke the pulley can still be rotated quite a bit before the valves show any new movement, enough so that I couldn't imagine being able determine the "0" degrees mark location by the valve actuation. I just want to understand the basics before I move on to set the timing. Thanks for reading this, any help would be greatly appreciated.
-
Deefer66
- Posts: 24
- Joined: Fri Dec 06, 2019 12:32 am
Re: Timing and TDC... type 4 confusion
With the engine together, if you want the true TDC you need to get something in the spark plug hole long enough to stop the piston. Some use a mod8fied pkugvwith a bolt fixed in or through it.
Carefully bring the piston up to this 'stop' and mark the pulley..go back the other way almost a full revolution and the piston will hit the 'stop' again.. Mark the pulley... TDC will be half way between your two marks.
Sent from my SM-G930F using Tapatalk
Carefully bring the piston up to this 'stop' and mark the pulley..go back the other way almost a full revolution and the piston will hit the 'stop' again.. Mark the pulley... TDC will be half way between your two marks.
Sent from my SM-G930F using Tapatalk
-
Deefer66
- Posts: 24
- Joined: Fri Dec 06, 2019 12:32 am
Re: Timing and TDC... type 4 confusion
.. just looking at old photos.
Red circle is the dent I had on the back face of the pulley/fan. This lines up with the 0 on the scale. The other marks I put on for TDC when building it line up with the case and can be seen through the inspection hole in the top of the fan housing
Sent from my SM-G930F using Tapatalk
Red circle is the dent I had on the back face of the pulley/fan. This lines up with the 0 on the scale. The other marks I put on for TDC when building it line up with the case and can be seen through the inspection hole in the top of the fan housing
Sent from my SM-G930F using Tapatalk