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Timing marks.

Posted: Mon Nov 10, 2008 6:29 am
by Hexadane
Can anyone maybe help me? our 1972 1800 bus had a service recently and the engine cleaner used washed the marks right off, im looking for a clear photo/diagram of where the marks are id greatly appreciate it :wink:

Re: Timing marks.

Posted: Mon Nov 10, 2008 9:47 am
by Blitzkrieg
I'd like to know the answer to this as well. My 1800 had a scale, but with all the marks wiped off as well :shock:

Hey, and if you ever rip out the engine and do a conversion, please keep me mind :wink:

Re: Timing marks.

Posted: Mon Nov 10, 2008 11:05 am
by Tony Z
Its actually very easy to put the marks back on. Primary school maths.

Measure the diameter of the pulley and multiply by 3.1415 - this gives you the circumferance.
Divide this by 360 and this now tells you how far apart each degree is from the other.

Put your engine onto TDC and mark off you zero mark. To the right on the pulley is before TDC and to the left (anticlockwise) is after. Remember, the pulley rotates clockwise from the engine bay when you look at it.

So if the circumf of the pulley is 360mm and you divide this by 360 degrees, then each degree is 1mm apart (if pulley is 720, then they are 2mm apart). Measure from TDC 8mm or 10mm or whatever it is depending on your timing and mark this.
Now with these 2 marks, take a file and file into your pulley a small V to indicate the mark and this wont get washed off.



If you have to find TDC, then do the following
Pull out a spark plug
thread in a bolt into the plug hole so that it reaches into the cylinder.
Turn the engine slowly by hand until you feel a piston touch the bolt (cover it in electrical tape to prevent any small nicks into the piston)
Mark this position on the pulley.
Turn the engine the other way until the piston softly touches again
Mark this position on the pulley.
TDC is exactly in the middle of these two positions.

Re: Timing marks.

Posted: Mon Nov 10, 2008 4:32 pm
by Hexadane
Thank you very much now i can sort the timing again and not go on guess :-)

ill keep it in mind next conversion i do ;-)

Re: Timing marks.

Posted: Tue Nov 11, 2008 6:11 am
by Ron&Gill
That is the simplest and most beautiful method of finding TDC I have ever read. Simple, accurate, beautiful. Thanks mon!

Re: Timing marks.

Posted: Tue Nov 11, 2008 8:54 am
by Tony Z
Cool, no problems....

Re: Timing marks.

Posted: Tue Nov 11, 2008 9:11 am
by vader
Well when you stuck in a boring port in the ass end of the world with nothing to do the whole day you come up with "flowery" explanations. hehehe

Good one Chrome Dome old buddy...