TDC TOOL

[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

[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.

[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)

[Tractorman]

You could make one with an old spark plug and an m8 nut and bolt.

[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.

[Tractorman]

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.

[Dimitrios_231]

Not always possible,
but...
...if the engine is out,I prefer this method.

[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

[Dimitrios_231]

Cheers,it is an original workshop tool for 125/150 and 175 cylinder studs spacing.



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.





This one is a remade for 200cc blocks.

[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