[Vwdiesel] More Quantum questions?

[mark shepherd]

Hi Bill,
If you need to refind TDC you can use the wire method, or seeing as that is 
a struggle to do accurately due to the almost stationary piston at TDC, I'd 
go for a version of what you suggested:

With cam cover off, turn engine until, by inspection, one cam lobe on #1 or 
#4 valve is opening. At this point slacken cam sprocket so that engine and 
pump can turn but leave cam still. If this point is unstable for the cam, 
then turn cam until cam lobe fully open. Gently rotate engine until piston 
rests on valve. Make a snowpeg/tippex mark on the flywheel through the TDC 
aperture.
Forget marking injection pump as this is both less accurate and will be lost 
information when you readjust the pump.
Rotate engine other way until  piston again rests on the same valve. Make 
your second mark on the fly wheel.

Using the teeth on the flywheel to interpolate, an extremely accurate TDC 
can be found.
Correct original timing mark for the diesel is an oval with a line through 
it.
Contrast with gasser flywheels, that have the oval for TDC and the timing 
mark line elsewhere eg 6 degrees BTDC.
Replacement alternative manufacturer flywheels naturally, don't have correct 
TDC marks, as they don't know what vehicle they are going on.

Now you can reset cam with a flat bar , and re-aline it to TDC on the 
flywheel. Then go through the pump timing proceedure.

Mark


----- Original Message ----- 
From: "William J Toensing" <toensing at wildblue.net>
To: <vwdiesel at vwfans.com>
Sent: Sunday, January 17, 2010 12:14 AM
Subject: [Vwdiesel] More Quantum questions?


>
> In attempting to clean  rust off the flywheel,  I accidentally erased the 
> "O" TDC mark on my flywheel. Is there a way to find & mark TDC on my 
> flywheel without removing the head to see when the #1 piston is at maximum 
> height? In attempting to re-time my engine I apparently moved the timming 
> off enough so that when I turn the engine over by hand, either clock wise 
> or contra clockwise, a piston hits a valve & you can't turn the engine 
> further. I have not tried to force it. I wonder if I could find TDC by 
> marking on the IP gear how far in either direction I could go till I hit a 
> valve with a piston, & mark TDC as half ways between these two points? Or 
> is TDC more than or less than half way between these two points? I just 
> checked & there are four gear points between the point where the piston 
> hits a valve.
> My suggestion would be to mark in a more permanent manor such as drilling 
> a small hole at TDC before doing any timming adjustments on the engine. If 
> I am wrong, please correct me.
> Bill Toensing, Nevada City, CA
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