Timing Gears + & - Markings

[Winston Teague]

Hi all, we are well and truly stuck into rebuilding an early coil bottom end. It has a 1 5/16 crank (without the oh-so-useful cutaway notches for knocking out the main bearings). The timing gears are both badly chipped and unserviceable. They are not marked with a mesh correction +/- figure and neither is the crankcase. I suspect that all the bits are original to the case ( the crank and flywheel are numbers matching). Does it pre-date meshing figures or does it mean that it is, in effect, +/- 0.00 thou?
If the latter does anyone have a good pair of zero gears available please?

All the best, Winston & Patrick Teague

[Ian Williams]

I have not seen an unmarked case, std ones through my hands have a zero with a diagonal like through it, have encountered a great many un marked gears though. I think we have long established that as all gears will be worn the best way when rebuilding an engine is to mix and match gears until an acceptable amount of lash is present. Also worth repeating that any wear peaks near the end of the teeth should be carefully removed otherwise gears will ride on these initially giving a false impression of lash, the teeth will also point load on these ridges and in many cases break as a result. Once you think you have fiddled around and found what appears to be a good set bluing is wise and can often reveal the true meshing picture.