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Re: Timing


On 31 Mar 2006 at 9:23, ken2k wrote:

> I just had the engine in my 71 square rebuilt. It ran ok but when i got it
> home and tried to check the timing it was way off, i had to set it by feel
> and ear. Now it runs great, the best it ever did but the timing mark is at
> about 11 oclock, if TDC is 0 degress. It has dual  carbs, not original, but
> balanced etc. What does this mean? is it a cause for concern or shoud i just
> be glad it runs well. Incidentally, before he rebuilt it the distributor was
> off 180 degrees.

There are a couple of things to be aware of here. One is that it is quite 
possible to time an engine by ear in such a way that it runs and sounds great 
but is really hard on the engine. Too much advance will do this, and in our 
case you don't want to go over more than about 32 deg advance total under load.

As to your observation, it's possible that you're looking at the wrong timing 
mark. For a '71 the timing marks look like

|     | | |

and the leftmost mark is TDC. If your timing marks don't look like this then 
TDC is elsewhere.

It's possible that your distributor mech advance is stuck. This is common and 
makes it necessary to compromise and set the idle timing high so that the 
timing is closer at speed. This is not a good compromise at all, so the best 
thing to do is to send the dist to me to be repaired. If yours is stuck, this 
will make a HUGE difference.

You can tell if yours is stuck by watching the timing marks move as you 
increase the rpms. They should move dramatically. If not, it's stuck. You can 
also test this by just grabbing the rotor by hand and twisting it CW. It should 
move a ways smoothly and then snap back smartly when you release it. Ignore any 
play in the drive dog and gear.

If he rebuilt it right, then the drive gear is back in there correctly now. 
We'll hope that's the case. Some people will correct this in the distributor, 
but this is a mistake, because you'll forget about it and then a different dist 
won't work right someday and you'll be confused all over again.

-- 
Jim Adney
jadney@vwtype3.org
Madison, WI 53711-3054
USA

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