Puppeteer

Author Topic: Lister CS 6/1 as form of rehab  (Read 8196 times)

mikenash

  • Sr. Member
  • ****
  • Posts: 407
    • View Profile
Re: Lister CS 6/1 as form of rehab
« Reply #165 on: September 16, 2018, 09:33:10 PM »
"greater manufacturing tolerances".  A generous term

ajaffa1

  • Hero Member
  • *****
  • Posts: 541
    • View Profile
Re: Lister CS 6/1 as form of rehab
« Reply #166 on: September 16, 2018, 09:46:21 PM »
Much easier to make shim washers in various thicknesses than to get your manufacturing tolerances right!

Bob

ajaffa1

  • Hero Member
  • *****
  • Posts: 541
    • View Profile
Re: Lister CS 6/1 as form of rehab
« Reply #167 on: September 17, 2018, 08:34:51 AM »
Well guys here is the info as promised. The gear on the crankshaft and The idler gear mesh very well and the faces are parallel. (please see photo) The camshaft gear is out of alignment towards the injector pump end by 20 thou, probably nothing to worry about.

The injector pump cam lobe is out off alignment, in the opposite direction, by about 30 thou. I have tossed the thick gasket I purchased and cut a thin paper replacement, this reduces the 30 thou to about 10 thou, hopefully within tolerance. (see pic)

The camshaft end float using the old worn bush and end cap now comes in at 25 thou. (see photo) I will take a very small skim off the end cap because it is pitted with rust and then turn a new cast iron bush to give me 5 thou of end float. I will also be taking a skim off the worn end of the camshaft(IP end) before turning the new Oilite bush to fit.

I have checked the lash in the timing gears, I have about 5 thou between the idler gear and the crankshaft pinion gear. I have about 10 thou between the idler gear and the camshaft gear. (done with feeler gauges)
I am thinking a new idler spigot with an off set of around 25 to 30 thou should get me in the ball park.

Advice please,

Bob



glort

  • Hero Member
  • *****
  • Posts: 1996
    • View Profile
Re: Lister CS 6/1 as form of rehab
« Reply #168 on: September 17, 2018, 12:16:58 PM »

Are these problems caused by wear or manufacturing defects Bob?

If it's manufacturing on a genuine lister, makes you wonder how bad 'Roids must be!

ajaffa1

  • Hero Member
  • *****
  • Posts: 541
    • View Profile
Re: Lister CS 6/1 as form of rehab
« Reply #169 on: September 17, 2018, 11:10:45 PM »
Hey Glort, It`s a mixture of wear and manufacturing defects.

The first issue was the new crankshaft and bush bearings being too short and having 30 thou of end float, without any gaskets under the bearing housings. Had to cut shims to get the end float down to 5 thou and use a liquid gasket. The crankshaft gear now aligns well with the original idler gear.

The second issue is wear in the idler gear and spigot which leaves me with 5 thou of lash with the crankshaft gear and 10 thou lash with the camshaft. I am sure this can be resolved with an offset spigot bolt.

The third issue is the alignment between the idler gear and the camshaft gear. This must be a manufacturing error on the original Lister! (please don`t throw things  ;D ) The wear in the steel bush and keeper have actually improved the alignment.

The last issue is the position of the new cam lobe for the injector pump. It is not centered under the injector roller. I have reduced the problem by using a much thinner gasket but it is still not right. I could get it spot on by adjusting the steel bush and keeper at the other end of the camshaft but this makes the gear alignment worse. I have wondered if this misalignment is deliberate allowing the non meshing 30 thou of the camshaft to act as an oil thrower to lubricate the brass bush and injector pump roller.

Anyone thinking they can repair a Lister cs by simply swapping worn parts for new Indian parts is going to be very disappointed, the tolerances and dimensions just don`t match.
Thoughts please.

Bob


ajaffa1

  • Hero Member
  • *****
  • Posts: 541
    • View Profile
Re: Lister CS 6/1 as form of rehab
« Reply #170 on: September 20, 2018, 07:32:28 AM »
Managed to get access to a mate`s lathe today, so I turned down the injector pump end of the camshaft by 25 thou. Turned a new bush from an over sized piece of Oilite. I am not going to bother to cut an oiler groove in this bush as the original didn`t have one and lasted for nearly sixty years.

I`ll have a go at an off set spigot for the idler gear tomorrow. I managed to salvage a suitable piece of steel from an old Land Rover gearbox. It was so hard that I couldn`t mark it with a file so I put it in our wood burning stove overnight to anneal it, nice and soft now. I should be able to harden and temper it afterwards.

Bob