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TDC TOOL

PostPosted: Thu Oct 15, 2015 7:24 pm
by kennystag
Hi all,
Anybody used TDC tool, are the any good for checking the timing.
Cheers
Stag
http://www.ebay.co.uk/itm/TDC-FINDER-TO ... 2ee6f384b8

Re: TDC TOOL

PostPosted: Thu Oct 15, 2015 7:33 pm
by dickie
I use one. It's ok, but use it as a stop rather than to find tdc itself, if you know what I mean.

The piston barely moves for a few degrees either side of tdc, so you need an accurate dial gauge to find tdc.

Re: TDC TOOL

PostPosted: Thu Oct 15, 2015 7:50 pm
by gaz_powell
I bought one but to be honest the calibration/measurement part is useless as already stated. Just make a stop from a spark plug (see stickys book) cost you 15 minutes and does the same job for the positive stop method (which I use all the time)

Re: TDC TOOL

PostPosted: Thu Oct 15, 2015 9:42 pm
by Tractorman
You could make one with an old spark plug and an m8 nut and bolt.

Re: TDC TOOL

PostPosted: Thu Oct 15, 2015 11:53 pm
by Storkfoot
I have always used one of those. But, you do have to rock the flywheel back and forth and have a keen eye.

The reason being that when you get near TDC the flywheel will keep turning but the "stop" stops moving. I gauge the midpoint between the "stop" stopping moving and then starting again. But, I check this point several times before I am sure I have TDC.

Many people favour measuring the midpoint between TDC and BDC. Personally, I think that is more liable to be wrong but it's all personal choice.

Re: TDC TOOL

PostPosted: Fri Oct 16, 2015 8:42 am
by Tractorman
Storkfoot wrote:I have always used one of those. But, you do have to rock the flywheel back and forth and have a keen eye.

The reason being that when you get near TDC the flywheel will keep turning but the "stop" stops moving. I gauge the midpoint between the "stop" stopping moving and then starting again. But, I check this point several times before I am sure I have TDC.

Many people favour measuring the midpoint between TDC and BDC. Personally, I think that is more liable to be wrong but it's all personal choice.


That's right the dwell point can be several degrees on the flywheel that is why IMO a fixed one set a few degrees before TDC is more accurate.

Re: TDC TOOL

PostPosted: Sat Oct 17, 2015 3:18 pm
by Dimitrios_231
Not always possible,
but...
...if the engine is out,I prefer this method.

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Re: TDC TOOL

PostPosted: Sat Oct 17, 2015 4:22 pm
by kennystag
Excellent you can’t go wrong with a dial gauge. If I fit electronic ignition I will use my dial gauge. I like the gauge stand, did you made it up yourself.
Cheers
Stag

Re: TDC TOOL

PostPosted: Sat Oct 17, 2015 4:57 pm
by Dimitrios_231
Cheers,it is an original workshop tool for 125/150 and 175 cylinder studs spacing.

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I also have a vintage TDC tool like the one that you described, next to a modern piston stop,
it is not as accurate as the dial gauge but it works.

Image

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This one is a remade for 200cc blocks.

Image

Re: TDC TOOL

PostPosted: Sat Oct 17, 2015 5:13 pm
by kennystag
Cracking tools mate,
I think I will have a go at making a dial gauge stand. I made a TDC tool with an old spark plug, same spec as in stickys book, but the dial gauge is the way to go for getting the timing set properly.
Cheers
Stag