Author Topic: Cam wheel marking for 2 3/4  (Read 3527 times)

0 Members and 1 Guest are viewing this topic.

Offline Chris54

  • Full Member
  • **
  • Join Date: May 2013
  • Posts: 72
  • Location: Copthorne, West Sussex
Cam wheel marking for 2 3/4
« on: 04 May 2015 at 07:22 »
Hi All

Can any of you shed some light on the markings on 2 3/4

I am rebuilding several engines and have a bunch of cam wheels that are marked up as 5, 5A or 5B

Is there a difference in the valve timing, would the B be the best to use as its probably the latest version, most improved.

Does anyone actually know, is there any literature on the subject.

Thanks in advance, Chris



Offline Doug

  • Global Moderator
  • ****
  • Join Date: Mar 2004
  • Posts: 3542
  • Location: Pennsylvania, USA

Offline Chris54

  • Full Member
  • **
  • Join Date: May 2013
  • Posts: 72
  • Location: Copthorne, West Sussex
Re: Cam wheel marking for 2 3/4
« Reply #2 on: 05 May 2015 at 07:32 »
Hi Doug
Many thanks for that, will study with interest

Chris

Offline Hutch

  • Senior Member
  • ***
  • Join Date: Nov 2012
  • Posts: 226
  • Location: Queensland, Australia
Re: Cam wheel marking for 2 3/4
« Reply #3 on: 05 May 2015 at 23:17 »
Hi Chris and Doug,
I found these cam timing diagrams in the The Douglas handbook 1916. This shows the timing of the "S" cam and "5" cam for 1915. No reference to how much lift each had tho'. Interesting the spelling of  "shewing" which I assume should be "showing"?

The "5" cam appears to be reasonable sporty and might have been in the "TT" models? No separate part number appears to be indicated in the parts list for the "S" or "5" cam.

Picture to follow as I'm having issues uploading the file......
Cheers

Ian

Offline Hutch

  • Senior Member
  • ***
  • Join Date: Nov 2012
  • Posts: 226
  • Location: Queensland, Australia
Re: Cam wheel marking for 2 3/4
« Reply #4 on: 06 May 2015 at 07:19 »
Not as high a resolution as i was trying before, but hopefully good enough to read.

Offline Hutch

  • Senior Member
  • ***
  • Join Date: Nov 2012
  • Posts: 226
  • Location: Queensland, Australia
Re: Cam wheel marking for 2 3/4
« Reply #5 on: 06 May 2015 at 07:20 »
and the number 5 cam

Offline Chris54

  • Full Member
  • **
  • Join Date: May 2013
  • Posts: 72
  • Location: Copthorne, West Sussex
Re: Cam wheel marking for 2 3/4
« Reply #6 on: 07 May 2015 at 06:52 »
Hi Ian

Ah light is being shed on the subject, we now have timing charts for the "S", "5", and "5B", just need the "5A", then to make a choice on which to use, the "5A" looks to have longer duration and more overlap.

The choice, safe, sporty or original, so a question, which one in a 1914 model U.

Cheers Chris 

Offline veikko1

  • Full Member
  • **
  • Join Date: Nov 2014
  • Posts: 39
  • Location: Finland
Re: Cam wheel marking for 2 3/4
« Reply #7 on: 07 May 2015 at 21:13 »
Hello Chris
I have looking, that you have 1914 model U. I repair similar model, and I am intersting see any pictures from your project.  Regards Veikko

 

motorcycle