TIMING GEARS

lostmind
lostmind Expert Adviser
edited November -1 in HUDSON

I have three new old stock fiber timing gears for sale.
The package is marked 41-51 six & eight cyl.
These match up to the used eight cyl. one in the photo.
Believe they are 20 degree?

Price is $15.00 each plus shipping

The used Hudson gear is $10.00 plus ship.

Email tunentime@ hotmail.com

Thanks Roy

Comments

  • Old Fogey UK
    Old Fogey UK Expert Adviser
    Oh shoot !!! I've just paid a heck of a lot more for one !
    The one on the right looks like the one I've just bought for my 1934 H8.
    If it will fit a 34, please let me know and you've sold one as a spare will be useful.
  • lostmind
    lostmind Expert Adviser
    Old Fogey, I think your gear has a different pitch
    on the teeth angle.This box is marked 20 degree
    but as you can see its not printed on.
    Somebody with more knowledge on this might help us out.
    Thanks Roy
  • bob ward
    bob ward Senior Contributor
    Early timing gears had a 14.5° pressure angle, the later ones had a 20° pressure angle, I'm not sure what year the change over occurred.

    Disregarding the technicalities of what the pressure angle is, importantly, it does subtly vary the shape of the gear teeth. This means that if you do mix them up, ie a 14.5° crank gear with a 20° cam gear or vice versa, you will get premature gear wear and failure.
  • Old Fogey UK
    Old Fogey UK Expert Adviser
    edited September 2011
    bob ward wrote:
    Early timing gears had a 14.5° pressure angle, the later ones had a 20° pressure angle, I'm not sure what year the change over occurred.

    Disregarding the technicalities of what the pressure angle is, importantly, it does subtly vary the shape of the gear teeth. This means that if you do mix them up, ie a 14.5° crank gear with a 20° cam gear or vice versa, you will get premature gear wear and failure.

    My initial problem was that my engine rebuilder used a new alloy timing gear from the Railton Owners Club with the old crank gear in my engine. The result was a severe graunching noise. So I bought a NOS set of both from Geoff Moore of the ROC.
    The box for the timing gear has 20 degrees written on it but it's been added at a later date with a felt pen. There's nothing at all on the box of the cam gear and nothing stamped on either gear themselves. However, Geoff said they're a matched set and I've taken his word on this.
    Is there a way of checking the angle of the gears ? I'm about to fit Geoff's set this weekend.
  • Huddy42
    Huddy42 Senior Contributor
    If you can tell me the thicness of the fibre gear and the number stamped on the steel gear I can tell you what you have.

    The early gears were thinner than the later 20 deg gears.All in all I think there were three thickness gears used over the years.
  • bob ward
    bob ward Senior Contributor
    Old Fogey UK wrote:

    Is there a way of checking the angle of the gears ?

    Not readily. It is possible but specialist gear measuring equipment is necessary.

    I do have an early NOS 14.5° fibre timing gear if you get desperate.

    Some info on how pressure angle changes gear tooth shape.
    http://shopswarf.orconhosting.net.nz/spur.html
This discussion has been closed.

Categories

In this Discussion