3 timing holes?

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NickCowley
Posts: 1
Joined: 03 Aug 2003, 01:33
Location: United Kingdom
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3 timing holes?

Post by NickCowley »

Hi all.
You seem like a knowledgable lot so maybe you can tell me why there appear to be three timing holes in the flywheel[?]
One must be TDC, so which one, and what are the other two?
Any thoughts appreciated.
Thanks,
Nick.
Dave Burns
Posts: 1915
Joined: 14 May 2001, 05:30
Location: United Kingdom
My Cars:
x 2

Post by Dave Burns »

Timing is carried out with No.4 piston at TDC, early engines have a plug in the head next to No.4 injector, you can unscrew it and use a probe (don't use a short probe incase you drop it) to touch the piston crown and determine TDC, your flywheel peg will then go into the appropriate hole.
If there isn't a probing hole in the head it gets a bit more difficult to find TDC, then the only way is to loosen No.4 injector (injector body, not just its pipe) and turn the engine until air can be heard escaping past the injector, (you must have the camshaft in the timed position to ensure No.4 cylinder's valves are closed, if not you won't be able to feel compression building) this tells you the rising piston is on its compression stroke, you want the top of this stroke for timing.

You should be able to feel TDC close enough to be able to insert the timing peg in the flywheel, as the crankshaft will become very easy to turn for a few degrees about TDC as there is no resistance from moving pistons.
<font color="red">WARNING, timing is set with No.4 piston at TDC this is at the cam belt end</font id="red">, do not get this mixed up.
Be warned also, there is no position on the camshaft that will allow the crankshaft to go through one complete revolution, there will always be a valve in the way so turn the crank slowly in case you come up against one, I'm assuming you have got the belt off and have completely lost the timing.
Dave
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