Author Topic: A65L Crankshaft welded sludge trap access  (Read 391 times)

0 Members and 1 Guest are viewing this topic.

Charles R

  • Star
  • *
  • Posts: 16
    • View Profile
A65L Crankshaft welded sludge trap access
« on: 01 November, 2017, 12:35:08 »
A65L 1970 (last of oil-in-tank)

Has anyone seen this before?  See photo of welded up sludge trap access (yes I know, it's a bit rusty too, but one thing at a time!).
I can't understand why anyone would wish to weld up the entry point when it could simply have a threaded cap fitted (loctited if thought necessary).
Now I've got the problem of what to do about it.

There are three obvious options:
1. buy a replacement crankshaft - not easy & quite expensive even as a used item (would need regrinding, new shells, etc)
2. re-machine the hole and tap it (difficult alignment problem) - also quite expensive as expect it to take about 3 hours
3. ignore the weld and fit it as it is!  (I will be fitting a cartridge oil filter, so sludge should not be an issue.)

Any comments or suggestions?

Cheers, Charles
« Last Edit: 01 November, 2017, 13:13:54 by Charles R »

JulianS

  • Empire Star
  • *****
  • Posts: 559
  • A10
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #1 on: 01 November, 2017, 13:30:37 »
I would not advise option 3 - firstly you do not know what is already contained in the sludge trap and secondly you do not know if the oilway from the main bearing journal has not been blocked or restricted by the welding.

Charles R

  • Star
  • *
  • Posts: 16
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #2 on: 01 November, 2017, 15:58:01 »
Thanks for the reply Julian.

I was intending to use a compressed air line to give it a good blow through after putting in some scavenging oil and letting it rest for a day or two.
After that I was going to set up a feed to the bushed bearing feed hole and see how freely the oil moves through to each big end.

BUT before all that I'm going to try and drill through the weld using tools in my shed.  I need to jury rig my bench drill press so it hangs over the bench then set up a solid table under it to give me the necessary clearance to hold the crankshaft under the drill bit.  Setting up will not be simple!

I still don't know why it was welded!

Cheers Charles

JulianS

  • Empire Star
  • *****
  • Posts: 559
  • A10
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #3 on: 01 November, 2017, 16:51:37 »
Sometimes the sludge build up is so hard it needs a drill or other mechanical means to move it, or so I have found. I would not rely on any solvent to loosen it or the small oil holes in the journal to allow the all effluent to escape.

The plugs were often removed with a hammer and cold chisel which often destroyed them and sometimes resulted in damage to the edges of the hole in the crankweb.

Mike Farmer

  • Royal Star
  • ***
  • Posts: 220
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #4 on: 01 November, 2017, 19:17:53 »
Hi

Do you know anyone with about a 3' pillar drill. You would then only have to align the crank. Where are you.

Mike 8)

Charles R

  • Star
  • *
  • Posts: 16
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #5 on: 02 November, 2017, 11:41:36 »
Mike

I don't know anyone locally with a floor standing pillar drill or anything approaching it.
I live near Halesworth/Harleston on the Suffolk/Norfolk border.

I'm still intrigued as to why it was welded.  This would have been done about 40 years ago and the motor has never been used since.  Perhaps there was a school of opinion that the sludge trap was not useful if an external filter was fitted but, even so, why weld the hole up?

Cheers, Charles

Mike Farmer

  • Royal Star
  • ***
  • Posts: 220
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #6 on: 02 November, 2017, 11:54:32 »
 :)

I discussed this with a local machinist today complete with piktur etc. Prob not a cheap job.

My thoughts for what its worth and what I would most likely do, and if this is frowned upon I understand.

Figuring that you're unlikely to need to do this again.

I would drill the weld, clean it completely and then weld it up again. Even suggesting this goes a bit against the grain but it would sort any faults inside the hole as well. Duff threads etc,

Finally please don't anybody threaten to lynch  for this suggestion.

Mike 8) 8) 8)

JulianS

  • Empire Star
  • *****
  • Posts: 559
  • A10
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #7 on: 02 November, 2017, 12:51:57 »
Even with an external filter there will still be some build up in the sludge trap.

I would think that it was welded as a bodge job, because the original plug was wrecked when removed and/or the face of the crankweb was damaged during removal and/or plug removed by drilling and the threads in the crankshaft were damaged in the process.

The plugs were secured by centre punching the edge and these marks often needed drilling to allow the plug to be unscrewed.

Mike Farmer

  • Royal Star
  • ***
  • Posts: 220
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #8 on: 02 November, 2017, 16:17:18 »
hi.

yep definitely a bodge job. cant see any other reason. some clown welded the locknut on the oil drive worm on my A50 prob they had tried to turn the nut the wrong way. Tuff really but that's life with something that's changed hands a zillion times.

Mike 8) 8) 8) 8) 8

Bess

  • Silver Star
  • ****
  • Posts: 255
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #9 on: 02 November, 2017, 16:29:52 »
Hi Mike,
            If after removing the welded section and you cant salvage the threads, my suggestion would be to make up a blank and braze it back. It could be removed easily removed if needed next rebuild.

Best wishes...

Charles R

  • Star
  • *
  • Posts: 16
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #10 on: 02 November, 2017, 16:50:12 »
Thank you all for your thoughts.

I would like to drill through and discover what's lurking:
 a. have they left the sludge trap still in there?
 b. is it clean in there?
 c. can the thread be reinstated?  (By the way, anyone know the thread size & type?)

Depending on what's found, ideally I'd like to reinstate the thread and fit a sludge trap plus plug.  Otherwise, as has been mentioned, seal it up again without a sludge trap so as to allow an external cartridge filter to do its job.

Cheers, Charles

JulianS

  • Empire Star
  • *****
  • Posts: 559
  • A10
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #11 on: 02 November, 2017, 17:00:37 »
7/8 x 20tpi.

Charles R

  • Star
  • *
  • Posts: 16
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #12 on: 02 November, 2017, 17:05:08 »
Thanks Julian

Which thread type?  Whitworth?

Cheers, Charles

JulianS

  • Empire Star
  • *****
  • Posts: 559
  • A10
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #13 on: 02 November, 2017, 17:07:26 »
Think it is cycle.

Mike Farmer

  • Royal Star
  • ***
  • Posts: 220
    • View Profile
Re: A65L Crankshaft welded sludge trap access
« Reply #14 on: 02 November, 2017, 19:28:35 »
Hi

Yep if it becomes necessary then I agree Brazing would be better than welding.

Mike 8)